mips: Add some missing syscalls for mips32

[valgrind.git] / coregrind / m_debuginfo / zstddeclib.c

/**
 * \file zstddeclib.c
 * Single-file Zstandard decompressor.
 *
 * Generate using:
 * \code
 *      python combine.py -r ../../lib -x legacy/zstd_legacy.h -o zstddeclib.c zstddeclib-in.c
 * \endcode
 */
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (copied below) and
 * the GPLv2 (found in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/*
BSD License

For Zstandard software

Copyright (c) Meta Platforms, Inc. and affiliates. All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

 * Redistributions of source code must retain the above copyright notice, this
   list of conditions and the following disclaimer.

 * Redistributions in binary form must reproduce the above copyright notice,
   this list of conditions and the following disclaimer in the documentation
   and/or other materials provided with the distribution.

 * Neither the name Facebook, nor Meta, nor the names of its contributors may
   be used to endorse or promote products derived from this software without
   specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Settings to bake for the standalone decompressor.
 *
 * Note: It's important that none of these affects 'zstd.h' (only the
 * implementation files we're amalgamating).
 *
 * Note: MEM_MODULE stops xxhash redefining BYTE, U16, etc., which are also
 * defined in mem.h (breaking C99 compatibility).
 *
 * Note: the undefs for xxHash allow Zstd's implementation to coincide with
 * standalone xxHash usage (with global defines).
 *
 * Note: if you enable ZSTD_LEGACY_SUPPORT the combine.py script will need
 * re-running without the "-x legacy/zstd_legacy.h" option (it excludes the
 * legacy support at the source level).
 */
#define DEBUGLEVEL 0
#define MEM_MODULE
#undef  XXH_NAMESPACE
#define XXH_NAMESPACE ZSTD_
#undef  XXH_PRIVATE_API
#define XXH_PRIVATE_API
#undef  XXH_INLINE_ALL
#define XXH_INLINE_ALL
#define ZSTD_LEGACY_SUPPORT 0
#define ZSTD_STRIP_ERROR_STRINGS
#define ZSTD_TRACE 0
/* TODO: Can't amalgamate ASM function */
#define ZSTD_DISABLE_ASM 1

/* Include zstd_deps.h first with all the options we need enabled. */
#define ZSTD_DEPS_NEED_MALLOC
/**** start inlining common/zstd_deps.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* This file provides common libc dependencies that zstd requires.
 * The purpose is to allow replacing this file with a custom implementation
 * to compile zstd without libc support.
 */

/* Need:
 * NULL
 * INT_MAX
 * UINT_MAX
 * ZSTD_memcpy()
 * ZSTD_memset()
 * ZSTD_memmove()
 */
#ifndef ZSTD_DEPS_COMMON
#define ZSTD_DEPS_COMMON

#include "pub_core_basics.h"
#include "pub_core_mallocfree.h"
#include "pub_core_libcbase.h"

# define ZSTD_memcpy(d,s,l) VG_(memcpy)((d),(s),(l))
# define ZSTD_memmove(d,s,l) VG_(memmove)((d),(s),(l))
# define ZSTD_memset(p,v,l) VG_(memset)((p),(v),(l))


#endif /* ZSTD_DEPS_COMMON */

/* Need:
 * ZSTD_malloc()
 * ZSTD_free()
 */
#ifdef ZSTD_DEPS_NEED_MALLOC
#ifndef ZSTD_DEPS_MALLOC
#define ZSTD_DEPS_MALLOC

#include <stdlib.h>

#define ZSTD_free(p) VG_(free)((p))

#endif /* ZSTD_DEPS_MALLOC */
#endif /* ZSTD_DEPS_NEED_MALLOC */

/*
 * Provides 64-bit math support.
 * Need:
 * U64 ZSTD_div64(U64 dividend, U32 divisor)
 */
#ifdef ZSTD_DEPS_NEED_MATH64
#ifndef ZSTD_DEPS_MATH64
#define ZSTD_DEPS_MATH64

#define ZSTD_div64(dividend, divisor) ((dividend) / (divisor))

#endif /* ZSTD_DEPS_MATH64 */
#endif /* ZSTD_DEPS_NEED_MATH64 */

/* Need:
 * assert()
 */
#ifdef ZSTD_DEPS_NEED_ASSERT
#ifndef ZSTD_DEPS_ASSERT
#define ZSTD_DEPS_ASSERT

#include <assert.h>

#endif /* ZSTD_DEPS_ASSERT */
#endif /* ZSTD_DEPS_NEED_ASSERT */

/* Need:
 * ZSTD_DEBUG_PRINT()
 */
#ifdef ZSTD_DEPS_NEED_IO
#ifndef ZSTD_DEPS_IO
#define ZSTD_DEPS_IO

#include <stdio.h>
#define ZSTD_DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)

#endif /* ZSTD_DEPS_IO */
#endif /* ZSTD_DEPS_NEED_IO */

/* Only requested when <stdint.h> is known to be present.
 * Need:
 * intptr_t
 */
#ifdef ZSTD_DEPS_NEED_STDINT
#ifndef ZSTD_DEPS_STDINT
#define ZSTD_DEPS_STDINT

#include <stdint.h>

#endif /* ZSTD_DEPS_STDINT */
#endif /* ZSTD_DEPS_NEED_STDINT */
/**** ended inlining common/zstd_deps.h ****/

/**** start inlining common/debug.c ****/
/* ******************************************************************
 * debug
 * Part of FSE library
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * You can contact the author at :
 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */


/*
 * This module only hosts one global variable
 * which can be used to dynamically influence the verbosity of traces,
 * such as DEBUGLOG and RAWLOG
 */

/**** start inlining debug.h ****/
/* ******************************************************************
 * debug
 * Part of FSE library
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * You can contact the author at :
 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */


/*
 * The purpose of this header is to enable debug functions.
 * They regroup assert(), DEBUGLOG() and RAWLOG() for run-time,
 * and DEBUG_STATIC_ASSERT() for compile-time.
 *
 * By default, DEBUGLEVEL==0, which means run-time debug is disabled.
 *
 * Level 1 enables assert() only.
 * Starting level 2, traces can be generated and pushed to stderr.
 * The higher the level, the more verbose the traces.
 *
 * It's possible to dynamically adjust level using variable g_debug_level,
 * which is only declared if DEBUGLEVEL>=2,
 * and is a global variable, not multi-thread protected (use with care)
 */

#ifndef DEBUG_H_12987983217
#define DEBUG_H_12987983217

#if defined (__cplusplus)
extern "C" {
#endif


/* static assert is triggered at compile time, leaving no runtime artefact.
 * static assert only works with compile-time constants.
 * Also, this variant can only be used inside a function. */
#define DEBUG_STATIC_ASSERT(c) (void)sizeof(char[(c) ? 1 : -1])


/* DEBUGLEVEL is expected to be defined externally,
 * typically through compiler command line.
 * Value must be a number. */
#ifndef DEBUGLEVEL
#  define DEBUGLEVEL 0
#endif


/* recommended values for DEBUGLEVEL :
 * 0 : release mode, no debug, all run-time checks disabled
 * 1 : enables assert() only, no display
 * 2 : reserved, for currently active debug path
 * 3 : events once per object lifetime (CCtx, CDict, etc.)
 * 4 : events once per frame
 * 5 : events once per block
 * 6 : events once per sequence (verbose)
 * 7+: events at every position (*very* verbose)
 *
 * It's generally inconvenient to output traces > 5.
 * In which case, it's possible to selectively trigger high verbosity levels
 * by modifying g_debug_level.
 */

#if (DEBUGLEVEL>=1)
#  define ZSTD_DEPS_NEED_ASSERT
/**** skipping file: zstd_deps.h ****/
#else
#  ifndef assert   /* assert may be already defined, due to prior #include <assert.h> */
#    define assert(condition) ((void)0)   /* disable assert (default) */
#  endif
#endif

#if (DEBUGLEVEL>=2)
#  define ZSTD_DEPS_NEED_IO
/**** skipping file: zstd_deps.h ****/
extern int g_debuglevel; /* the variable is only declared,
                            it actually lives in debug.c,
                            and is shared by the whole process.
                            It's not thread-safe.
                            It's useful when enabling very verbose levels
                            on selective conditions (such as position in src) */

#  define RAWLOG(l, ...)                   \
    do {                                   \
        if (l<=g_debuglevel) {             \
            ZSTD_DEBUG_PRINT(__VA_ARGS__); \
        }                                  \
    } while (0)

#define STRINGIFY(x) #x
#define TOSTRING(x) STRINGIFY(x)
#define LINE_AS_STRING TOSTRING(__LINE__)

#  define DEBUGLOG(l, ...)                               \
    do {                                                 \
        if (l<=g_debuglevel) {                           \
            ZSTD_DEBUG_PRINT(__FILE__ ":" LINE_AS_STRING ": " __VA_ARGS__); \
            ZSTD_DEBUG_PRINT(" \n");                     \
        }                                                \
    } while (0)
#else
#  define RAWLOG(l, ...)   do { } while (0)    /* disabled */
#  define DEBUGLOG(l, ...) do { } while (0)    /* disabled */
#endif


#if defined (__cplusplus)
}
#endif

#endif /* DEBUG_H_12987983217 */
/**** ended inlining debug.h ****/

#if !defined(ZSTD_LINUX_KERNEL) || (DEBUGLEVEL>=2)
/* We only use this when DEBUGLEVEL>=2, but we get -Werror=pedantic errors if a
 * translation unit is empty. So remove this from Linux kernel builds, but
 * otherwise just leave it in.
 */
int g_debuglevel = DEBUGLEVEL;
#endif
/**** ended inlining common/debug.c ****/
/**** start inlining common/entropy_common.c ****/
/* ******************************************************************
 * Common functions of New Generation Entropy library
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 *  You can contact the author at :
 *  - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *  - Public forum : https://groups.google.com/forum/#!forum/lz4c
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */

/* *************************************
*  Dependencies
***************************************/
/**** start inlining mem.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef MEM_H_MODULE
#define MEM_H_MODULE

#if defined (__cplusplus)
extern "C" {
#endif

/*-****************************************
*  Dependencies
******************************************/
#include <stddef.h>  /* size_t, ptrdiff_t */
/**** start inlining compiler.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_COMPILER_H
#define ZSTD_COMPILER_H

#include <stddef.h>

/**** start inlining portability_macros.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_PORTABILITY_MACROS_H
#define ZSTD_PORTABILITY_MACROS_H

/**
 * This header file contains macro definitions to support portability.
 * This header is shared between C and ASM code, so it MUST only
 * contain macro definitions. It MUST not contain any C code.
 *
 * This header ONLY defines macros to detect platforms/feature support.
 *
 */


/* compat. with non-clang compilers */
#ifndef __has_attribute
  #define __has_attribute(x) 0
#endif

/* compat. with non-clang compilers */
#ifndef __has_builtin
#  define __has_builtin(x) 0
#endif

/* compat. with non-clang compilers */
#ifndef __has_feature
#  define __has_feature(x) 0
#endif

/* detects whether we are being compiled under msan */
#ifndef ZSTD_MEMORY_SANITIZER
#  if __has_feature(memory_sanitizer)
#    define ZSTD_MEMORY_SANITIZER 1
#  else
#    define ZSTD_MEMORY_SANITIZER 0
#  endif
#endif

/* detects whether we are being compiled under asan */
#ifndef ZSTD_ADDRESS_SANITIZER
#  if __has_feature(address_sanitizer)
#    define ZSTD_ADDRESS_SANITIZER 1
#  elif defined(__SANITIZE_ADDRESS__)
#    define ZSTD_ADDRESS_SANITIZER 1
#  else
#    define ZSTD_ADDRESS_SANITIZER 0
#  endif
#endif

/* detects whether we are being compiled under dfsan */
#ifndef ZSTD_DATAFLOW_SANITIZER
# if __has_feature(dataflow_sanitizer)
#  define ZSTD_DATAFLOW_SANITIZER 1
# else
#  define ZSTD_DATAFLOW_SANITIZER 0
# endif
#endif

/* Mark the internal assembly functions as hidden  */
#ifdef __ELF__
# define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func
#elif defined(__APPLE__)
# define ZSTD_HIDE_ASM_FUNCTION(func) .private_extern func
#else
# define ZSTD_HIDE_ASM_FUNCTION(func)
#endif

/* Enable runtime BMI2 dispatch based on the CPU.
 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default.
 */
#ifndef DYNAMIC_BMI2
  #if ((defined(__clang__) && __has_attribute(__target__)) \
      || (defined(__GNUC__) \
          && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \
      && (defined(__x86_64__) || defined(_M_X64)) \
      && !defined(__BMI2__)
  #  define DYNAMIC_BMI2 1
  #else
  #  define DYNAMIC_BMI2 0
  #endif
#endif

/**
 * Only enable assembly for GNUC compatible compilers,
 * because other platforms may not support GAS assembly syntax.
 *
 * Only enable assembly for Linux / MacOS, other platforms may
 * work, but they haven't been tested. This could likely be
 * extended to BSD systems.
 *
 * Disable assembly when MSAN is enabled, because MSAN requires
 * 100% of code to be instrumented to work.
 */
#if defined(__GNUC__)
#  if defined(__linux__) || defined(__linux) || defined(__APPLE__)
#    if ZSTD_MEMORY_SANITIZER
#      define ZSTD_ASM_SUPPORTED 0
#    elif ZSTD_DATAFLOW_SANITIZER
#      define ZSTD_ASM_SUPPORTED 0
#    else
#      define ZSTD_ASM_SUPPORTED 1
#    endif
#  else
#    define ZSTD_ASM_SUPPORTED 0
#  endif
#else
#  define ZSTD_ASM_SUPPORTED 0
#endif

/**
 * Determines whether we should enable assembly for x86-64
 * with BMI2.
 *
 * Enable if all of the following conditions hold:
 * - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM
 * - Assembly is supported
 * - We are compiling for x86-64 and either:
 *   - DYNAMIC_BMI2 is enabled
 *   - BMI2 is supported at compile time
 */
#if !defined(ZSTD_DISABLE_ASM) &&                                 \
    ZSTD_ASM_SUPPORTED &&                                         \
    defined(__x86_64__) &&                                        \
    (DYNAMIC_BMI2 || defined(__BMI2__))
# define ZSTD_ENABLE_ASM_X86_64_BMI2 1
#else
# define ZSTD_ENABLE_ASM_X86_64_BMI2 0
#endif

/*
 * For x86 ELF targets, add .note.gnu.property section for Intel CET in
 * assembly sources when CET is enabled.
 *
 * Additionally, any function that may be called indirectly must begin
 * with ZSTD_CET_ENDBRANCH.
 */
#if defined(__ELF__) && (defined(__x86_64__) || defined(__i386__)) \
    && defined(__has_include)
# if __has_include(<cet.h>)
#  include <cet.h>
#  define ZSTD_CET_ENDBRANCH _CET_ENDBR
# endif
#endif

#ifndef ZSTD_CET_ENDBRANCH
# define ZSTD_CET_ENDBRANCH
#endif

#endif /* ZSTD_PORTABILITY_MACROS_H */
/**** ended inlining portability_macros.h ****/

/*-*******************************************************
*  Compiler specifics
*********************************************************/
/* force inlining */

#if !defined(ZSTD_NO_INLINE)
#if (defined(__GNUC__) && !defined(__STRICT_ANSI__)) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
#  define INLINE_KEYWORD inline
#else
#  define INLINE_KEYWORD
#endif

#if defined(__GNUC__) || defined(__ICCARM__)
#  define FORCE_INLINE_ATTR __attribute__((always_inline))
#elif defined(_MSC_VER)
#  define FORCE_INLINE_ATTR __forceinline
#else
#  define FORCE_INLINE_ATTR
#endif

#else

#define INLINE_KEYWORD
#define FORCE_INLINE_ATTR

#endif

/**
  On MSVC qsort requires that functions passed into it use the __cdecl calling conversion(CC).
  This explicitly marks such functions as __cdecl so that the code will still compile
  if a CC other than __cdecl has been made the default.
*/
#if  defined(_MSC_VER)
#  define WIN_CDECL __cdecl
#else
#  define WIN_CDECL
#endif

/* UNUSED_ATTR tells the compiler it is okay if the function is unused. */
#if defined(__GNUC__)
#  define UNUSED_ATTR __attribute__((unused))
#else
#  define UNUSED_ATTR
#endif

/**
 * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant
 * parameters. They must be inlined for the compiler to eliminate the constant
 * branches.
 */
#define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR UNUSED_ATTR
/**
 * HINT_INLINE is used to help the compiler generate better code. It is *not*
 * used for "templates", so it can be tweaked based on the compilers
 * performance.
 *
 * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the
 * always_inline attribute.
 *
 * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline
 * attribute.
 */
#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5
#  define HINT_INLINE static INLINE_KEYWORD
#else
#  define HINT_INLINE FORCE_INLINE_TEMPLATE
#endif

/* "soft" inline :
 * The compiler is free to select if it's a good idea to inline or not.
 * The main objective is to silence compiler warnings
 * when a defined function in included but not used.
 *
 * Note : this macro is prefixed `MEM_` because it used to be provided by `mem.h` unit.
 * Updating the prefix is probably preferable, but requires a fairly large codemod,
 * since this name is used everywhere.
 */
#ifndef MEM_STATIC  /* already defined in Linux Kernel mem.h */
#if defined(__GNUC__)
#  define MEM_STATIC static __inline UNUSED_ATTR
#elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#  define MEM_STATIC static inline
#elif defined(_MSC_VER)
#  define MEM_STATIC static __inline
#else
#  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
#endif
#endif

/* force no inlining */
#ifdef _MSC_VER
#  define FORCE_NOINLINE static __declspec(noinline)
#else
#  if defined(__GNUC__) || defined(__ICCARM__)
#    define FORCE_NOINLINE static __attribute__((__noinline__))
#  else
#    define FORCE_NOINLINE static
#  endif
#endif


/* target attribute */
#if defined(__GNUC__) || defined(__ICCARM__)
#  define TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
#else
#  define TARGET_ATTRIBUTE(target)
#endif

/* Target attribute for BMI2 dynamic dispatch.
 * Enable lzcnt, bmi, and bmi2.
 * We test for bmi1 & bmi2. lzcnt is included in bmi1.
 */
#define BMI2_TARGET_ATTRIBUTE TARGET_ATTRIBUTE("lzcnt,bmi,bmi2")

/* prefetch
 * can be disabled, by declaring NO_PREFETCH build macro */
#if defined(NO_PREFETCH)
#  define PREFETCH_L1(ptr)  do { (void)(ptr); } while (0)  /* disabled */
#  define PREFETCH_L2(ptr)  do { (void)(ptr); } while (0)  /* disabled */
#else
#  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86)) && !defined(_M_ARM64EC)  /* _mm_prefetch() is not defined outside of x86/x64 */
#    include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
#    define PREFETCH_L1(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
#    define PREFETCH_L2(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T1)
#  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
#    define PREFETCH_L1(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
#    define PREFETCH_L2(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */)
#  elif defined(__aarch64__)
#    define PREFETCH_L1(ptr)  do { __asm__ __volatile__("prfm pldl1keep, %0" ::"Q"(*(ptr))); } while (0)
#    define PREFETCH_L2(ptr)  do { __asm__ __volatile__("prfm pldl2keep, %0" ::"Q"(*(ptr))); } while (0)
#  else
#    define PREFETCH_L1(ptr) do { (void)(ptr); } while (0)  /* disabled */
#    define PREFETCH_L2(ptr) do { (void)(ptr); } while (0)  /* disabled */
#  endif
#endif  /* NO_PREFETCH */

#define CACHELINE_SIZE 64

#define PREFETCH_AREA(p, s)                              \
    do {                                                 \
        const char* const _ptr = (const char*)(p);       \
        size_t const _size = (size_t)(s);                \
        size_t _pos;                                     \
        for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) { \
            PREFETCH_L2(_ptr + _pos);                    \
        }                                                \
    } while (0)

/* vectorization
 * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax,
 * and some compilers, like Intel ICC and MCST LCC, do not support it at all. */
#if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__) && !defined(__LCC__)
#  if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5)
#    define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
#  else
#    define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-vectorize\")")
#  endif
#else
#  define DONT_VECTORIZE
#endif

/* Tell the compiler that a branch is likely or unlikely.
 * Only use these macros if it causes the compiler to generate better code.
 * If you can remove a LIKELY/UNLIKELY annotation without speed changes in gcc
 * and clang, please do.
 */


#if __has_builtin(__builtin_unreachable) || (defined(__GNUC__) && (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)))
#  define ZSTD_UNREACHABLE do { assert(0), __builtin_unreachable(); } while (0)
#else
#  define ZSTD_UNREACHABLE do { assert(0); } while (0)
#endif

/* disable warnings */
#ifdef _MSC_VER    /* Visual Studio */
#  include <intrin.h>                    /* For Visual 2005 */
#  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
#  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
#  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
#  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
#  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
#endif

/*Like DYNAMIC_BMI2 but for compile time determination of BMI2 support*/
#ifndef STATIC_BMI2
#  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))
#    ifdef __AVX2__  //MSVC does not have a BMI2 specific flag, but every CPU that supports AVX2 also supports BMI2
#       define STATIC_BMI2 1
#    endif
#  elif defined(__BMI2__) && defined(__x86_64__) && defined(__GNUC__)
#    define STATIC_BMI2 1
#  endif
#endif

#ifndef STATIC_BMI2
    #define STATIC_BMI2 0
#endif

/* compile time determination of SIMD support */
#if !defined(ZSTD_NO_INTRINSICS)
#  if defined(__SSE2__) || defined(_M_AMD64) || (defined (_M_IX86) && defined(_M_IX86_FP) && (_M_IX86_FP >= 2))
#    define ZSTD_ARCH_X86_SSE2
#  endif
#  if defined(__ARM_NEON) || defined(_M_ARM64)
#    define ZSTD_ARCH_ARM_NEON
#  endif
#
#  if defined(ZSTD_ARCH_X86_SSE2)
#    include <emmintrin.h>
#  elif defined(ZSTD_ARCH_ARM_NEON)
#    include <arm_neon.h>
#  endif
#endif

/* C-language Attributes are added in C23. */
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute)
# define ZSTD_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
#else
# define ZSTD_HAS_C_ATTRIBUTE(x) 0
#endif

/* Only use C++ attributes in C++. Some compilers report support for C++
 * attributes when compiling with C.
 */
#if defined(__cplusplus) && defined(__has_cpp_attribute)
# define ZSTD_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
#else
# define ZSTD_HAS_CPP_ATTRIBUTE(x) 0
#endif

/* Define ZSTD_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute.
 * - C23: https://en.cppreference.com/w/c/language/attributes/fallthrough
 * - CPP17: https://en.cppreference.com/w/cpp/language/attributes/fallthrough
 * - Else: __attribute__((__fallthrough__))
 */
#ifndef ZSTD_FALLTHROUGH
# if ZSTD_HAS_C_ATTRIBUTE(fallthrough)
#  define ZSTD_FALLTHROUGH [[fallthrough]]
# elif ZSTD_HAS_CPP_ATTRIBUTE(fallthrough)
#  define ZSTD_FALLTHROUGH [[fallthrough]]
# elif __has_attribute(__fallthrough__)
/* Leading semicolon is to satisfy gcc-11 with -pedantic. Without the semicolon
 * gcc complains about: a label can only be part of a statement and a declaration is not a statement.
 */
#  define ZSTD_FALLTHROUGH ; __attribute__((__fallthrough__))
# else
#  define ZSTD_FALLTHROUGH
# endif
#endif

/*-**************************************************************
*  Alignment check
*****************************************************************/

/* this test was initially positioned in mem.h,
 * but this file is removed (or replaced) for linux kernel
 * so it's now hosted in compiler.h,
 * which remains valid for both user & kernel spaces.
 */

#ifndef ZSTD_ALIGNOF
# if defined(__GNUC__) || defined(_MSC_VER)
/* covers gcc, clang & MSVC */
/* note : this section must come first, before C11,
 * due to a limitation in the kernel source generator */
#  define ZSTD_ALIGNOF(T) __alignof(T)

# elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
/* C11 support */
#  include <stdalign.h>
#  define ZSTD_ALIGNOF(T) alignof(T)

# else
/* No known support for alignof() - imperfect backup */
#  define ZSTD_ALIGNOF(T) (sizeof(void*) < sizeof(T) ? sizeof(void*) : sizeof(T))

# endif
#endif /* ZSTD_ALIGNOF */

/*-**************************************************************
*  Sanitizer
*****************************************************************/

/**
 * Zstd relies on pointer overflow in its decompressor.
 * We add this attribute to functions that rely on pointer overflow.
 */
#ifndef ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
#  if __has_attribute(no_sanitize)
#    if !defined(__clang__) && defined(__GNUC__) && __GNUC__ < 8
       /* gcc < 8 only has signed-integer-overlow which triggers on pointer overflow */
#      define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR __attribute__((no_sanitize("signed-integer-overflow")))
#    else
       /* older versions of clang [3.7, 5.0) will warn that pointer-overflow is ignored. */
#      define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR __attribute__((no_sanitize("pointer-overflow")))
#    endif
#  else
#    define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
#  endif
#endif

/**
 * Helper function to perform a wrapped pointer difference without trigging
 * UBSAN.
 *
 * @returns lhs - rhs with wrapping
 */
MEM_STATIC
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
ptrdiff_t ZSTD_wrappedPtrDiff(unsigned char const* lhs, unsigned char const* rhs)
{
    return lhs - rhs;
}

/**
 * Helper function to perform a wrapped pointer add without triggering UBSAN.
 *
 * @return ptr + add with wrapping
 */
MEM_STATIC
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
unsigned char const* ZSTD_wrappedPtrAdd(unsigned char const* ptr, ptrdiff_t add)
{
    return ptr + add;
}

/**
 * Helper function to perform a wrapped pointer subtraction without triggering
 * UBSAN.
 *
 * @return ptr - sub with wrapping
 */
MEM_STATIC
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
unsigned char const* ZSTD_wrappedPtrSub(unsigned char const* ptr, ptrdiff_t sub)
{
    return ptr - sub;
}

/**
 * Helper function to add to a pointer that works around C's undefined behavior
 * of adding 0 to NULL.
 *
 * @returns `ptr + add` except it defines `NULL + 0 == NULL`.
 */
MEM_STATIC
unsigned char* ZSTD_maybeNullPtrAdd(unsigned char* ptr, ptrdiff_t add)
{
    return add > 0 ? ptr + add : ptr;
}

/* Issue #3240 reports an ASAN failure on an llvm-mingw build. Out of an
 * abundance of caution, disable our custom poisoning on mingw. */
#ifdef __MINGW32__
#ifndef ZSTD_ASAN_DONT_POISON_WORKSPACE
#define ZSTD_ASAN_DONT_POISON_WORKSPACE 1
#endif
#ifndef ZSTD_MSAN_DONT_POISON_WORKSPACE
#define ZSTD_MSAN_DONT_POISON_WORKSPACE 1
#endif
#endif

#if ZSTD_MEMORY_SANITIZER && !defined(ZSTD_MSAN_DONT_POISON_WORKSPACE)
/* Not all platforms that support msan provide sanitizers/msan_interface.h.
 * We therefore declare the functions we need ourselves, rather than trying to
 * include the header file... */
#include <stddef.h>  /* size_t */
#define ZSTD_DEPS_NEED_STDINT
/**** skipping file: zstd_deps.h ****/

/* Make memory region fully initialized (without changing its contents). */
void __msan_unpoison(const volatile void *a, size_t size);

/* Make memory region fully uninitialized (without changing its contents).
   This is a legacy interface that does not update origin information. Use
   __msan_allocated_memory() instead. */
void __msan_poison(const volatile void *a, size_t size);

/* Returns the offset of the first (at least partially) poisoned byte in the
   memory range, or -1 if the whole range is good. */
intptr_t __msan_test_shadow(const volatile void *x, size_t size);

/* Print shadow and origin for the memory range to stderr in a human-readable
   format. */
void __msan_print_shadow(const volatile void *x, size_t size);
#endif

#if ZSTD_ADDRESS_SANITIZER && !defined(ZSTD_ASAN_DONT_POISON_WORKSPACE)
/* Not all platforms that support asan provide sanitizers/asan_interface.h.
 * We therefore declare the functions we need ourselves, rather than trying to
 * include the header file... */
#include <stddef.h>  /* size_t */

/**
 * Marks a memory region (<c>[addr, addr+size)</c>) as unaddressable.
 *
 * This memory must be previously allocated by your program. Instrumented
 * code is forbidden from accessing addresses in this region until it is
 * unpoisoned. This function is not guaranteed to poison the entire region -
 * it could poison only a subregion of <c>[addr, addr+size)</c> due to ASan
 * alignment restrictions.
 *
 * \note This function is not thread-safe because no two threads can poison or
 * unpoison memory in the same memory region simultaneously.
 *
 * \param addr Start of memory region.
 * \param size Size of memory region. */
void __asan_poison_memory_region(void const volatile *addr, size_t size);

/**
 * Marks a memory region (<c>[addr, addr+size)</c>) as addressable.
 *
 * This memory must be previously allocated by your program. Accessing
 * addresses in this region is allowed until this region is poisoned again.
 * This function could unpoison a super-region of <c>[addr, addr+size)</c> due
 * to ASan alignment restrictions.
 *
 * \note This function is not thread-safe because no two threads can
 * poison or unpoison memory in the same memory region simultaneously.
 *
 * \param addr Start of memory region.
 * \param size Size of memory region. */
void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
#endif

#endif /* ZSTD_COMPILER_H */
/**** ended inlining compiler.h ****/
/**** skipping file: debug.h ****/
/**** skipping file: zstd_deps.h ****/


/*-****************************************
*  Compiler specifics
******************************************/
#if defined(_MSC_VER)   /* Visual Studio */
#   include <stdlib.h>  /* _byteswap_ulong */
#   include <intrin.h>  /* _byteswap_* */
#endif

/*-**************************************************************
*  Basic Types
*****************************************************************/
#if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
#  if defined(_AIX)
#    include <inttypes.h>
#  else
#    include <stdint.h> /* intptr_t */
#  endif
  typedef   uint8_t BYTE;
  typedef   uint8_t U8;
  typedef    int8_t S8;
  typedef  uint16_t U16;
  typedef   int16_t S16;
  typedef  uint32_t U32;
  typedef   int32_t S32;
  typedef  uint64_t U64;
  typedef   int64_t S64;
#else
# include <limits.h>
#if CHAR_BIT != 8
#  error "this implementation requires char to be exactly 8-bit type"
#endif
  typedef unsigned char      BYTE;
  typedef unsigned char      U8;
  typedef   signed char      S8;
#if USHRT_MAX != 65535
#  error "this implementation requires short to be exactly 16-bit type"
#endif
  typedef unsigned short      U16;
  typedef   signed short      S16;
#if UINT_MAX != 4294967295
#  error "this implementation requires int to be exactly 32-bit type"
#endif
  typedef unsigned int        U32;
  typedef   signed int        S32;
/* note : there are no limits defined for long long type in C90.
 * limits exist in C99, however, in such case, <stdint.h> is preferred */
  typedef unsigned long long  U64;
  typedef   signed long long  S64;
#endif


/*-**************************************************************
*  Memory I/O API
*****************************************************************/
/*=== Static platform detection ===*/
MEM_STATIC unsigned MEM_32bits(void);
MEM_STATIC unsigned MEM_64bits(void);
MEM_STATIC unsigned MEM_isLittleEndian(void);

/*=== Native unaligned read/write ===*/
MEM_STATIC U16 MEM_read16(const void* memPtr);
MEM_STATIC U32 MEM_read32(const void* memPtr);
MEM_STATIC U64 MEM_read64(const void* memPtr);
MEM_STATIC size_t MEM_readST(const void* memPtr);

MEM_STATIC void MEM_write16(void* memPtr, U16 value);
MEM_STATIC void MEM_write32(void* memPtr, U32 value);
MEM_STATIC void MEM_write64(void* memPtr, U64 value);

/*=== Little endian unaligned read/write ===*/
MEM_STATIC U16 MEM_readLE16(const void* memPtr);
MEM_STATIC U32 MEM_readLE24(const void* memPtr);
MEM_STATIC U32 MEM_readLE32(const void* memPtr);
MEM_STATIC U64 MEM_readLE64(const void* memPtr);
MEM_STATIC size_t MEM_readLEST(const void* memPtr);

MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val);
MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val);
MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32);
MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64);
MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val);

/*=== Big endian unaligned read/write ===*/
MEM_STATIC U32 MEM_readBE32(const void* memPtr);
MEM_STATIC U64 MEM_readBE64(const void* memPtr);
MEM_STATIC size_t MEM_readBEST(const void* memPtr);

MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32);
MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64);
MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val);

/*=== Byteswap ===*/
MEM_STATIC U32 MEM_swap32(U32 in);
MEM_STATIC U64 MEM_swap64(U64 in);
MEM_STATIC size_t MEM_swapST(size_t in);


/*-**************************************************************
*  Memory I/O Implementation
*****************************************************************/
/* MEM_FORCE_MEMORY_ACCESS : For accessing unaligned memory:
 * Method 0 : always use `memcpy()`. Safe and portable.
 * Method 1 : Use compiler extension to set unaligned access.
 * Method 2 : direct access. This method is portable but violate C standard.
 *            It can generate buggy code on targets depending on alignment.
 * Default  : method 1 if supported, else method 0
 */
#ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
#  ifdef __GNUC__
#    define MEM_FORCE_MEMORY_ACCESS 1
#  endif
#endif

MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }

MEM_STATIC unsigned MEM_isLittleEndian(void)
{
#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
    return 1;
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
    return 0;
#elif defined(__clang__) && __LITTLE_ENDIAN__
    return 1;
#elif defined(__clang__) && __BIG_ENDIAN__
    return 0;
#elif defined(_MSC_VER) && (_M_AMD64 || _M_IX86)
    return 1;
#elif defined(__DMC__) && defined(_M_IX86)
    return 1;
#else
    const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
    return one.c[0];
#endif
}

#if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)

/* violates C standard, by lying on structure alignment.
Only use if no other choice to achieve best performance on target platform */
MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; }

MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; }
MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; }

#elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)

typedef __attribute__((aligned(1))) U16 unalign16;
typedef __attribute__((aligned(1))) U32 unalign32;
typedef __attribute__((aligned(1))) U64 unalign64;
typedef __attribute__((aligned(1))) size_t unalignArch;

MEM_STATIC U16 MEM_read16(const void* ptr) { return *(const unalign16*)ptr; }
MEM_STATIC U32 MEM_read32(const void* ptr) { return *(const unalign32*)ptr; }
MEM_STATIC U64 MEM_read64(const void* ptr) { return *(const unalign64*)ptr; }
MEM_STATIC size_t MEM_readST(const void* ptr) { return *(const unalignArch*)ptr; }

MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(unalign16*)memPtr = value; }
MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(unalign32*)memPtr = value; }
MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(unalign64*)memPtr = value; }

#else

/* default method, safe and standard.
   can sometimes prove slower */

MEM_STATIC U16 MEM_read16(const void* memPtr)
{
    U16 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}

MEM_STATIC U32 MEM_read32(const void* memPtr)
{
    U32 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}

MEM_STATIC U64 MEM_read64(const void* memPtr)
{
    U64 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}

MEM_STATIC size_t MEM_readST(const void* memPtr)
{
    size_t val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}

MEM_STATIC void MEM_write16(void* memPtr, U16 value)
{
    ZSTD_memcpy(memPtr, &value, sizeof(value));
}

MEM_STATIC void MEM_write32(void* memPtr, U32 value)
{
    ZSTD_memcpy(memPtr, &value, sizeof(value));
}

MEM_STATIC void MEM_write64(void* memPtr, U64 value)
{
    ZSTD_memcpy(memPtr, &value, sizeof(value));
}

#endif /* MEM_FORCE_MEMORY_ACCESS */

MEM_STATIC U32 MEM_swap32_fallback(U32 in)
{
    return  ((in << 24) & 0xff000000 ) |
            ((in <<  8) & 0x00ff0000 ) |
            ((in >>  8) & 0x0000ff00 ) |
            ((in >> 24) & 0x000000ff );
}

MEM_STATIC U32 MEM_swap32(U32 in)
{
#if defined(_MSC_VER)     /* Visual Studio */
    return _byteswap_ulong(in);
#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
  || (defined(__clang__) && __has_builtin(__builtin_bswap32))
    return __builtin_bswap32(in);
#else
    return MEM_swap32_fallback(in);
#endif
}

MEM_STATIC U64 MEM_swap64_fallback(U64 in)
{
     return  ((in << 56) & 0xff00000000000000ULL) |
            ((in << 40) & 0x00ff000000000000ULL) |
            ((in << 24) & 0x0000ff0000000000ULL) |
            ((in << 8)  & 0x000000ff00000000ULL) |
            ((in >> 8)  & 0x00000000ff000000ULL) |
            ((in >> 24) & 0x0000000000ff0000ULL) |
            ((in >> 40) & 0x000000000000ff00ULL) |
            ((in >> 56) & 0x00000000000000ffULL);
}

MEM_STATIC U64 MEM_swap64(U64 in)
{
#if defined(_MSC_VER)     /* Visual Studio */
    return _byteswap_uint64(in);
#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
  || (defined(__clang__) && __has_builtin(__builtin_bswap64))
    return __builtin_bswap64(in);
#else
    return MEM_swap64_fallback(in);
#endif
}

MEM_STATIC size_t MEM_swapST(size_t in)
{
    if (MEM_32bits())
        return (size_t)MEM_swap32((U32)in);
    else
        return (size_t)MEM_swap64((U64)in);
}

/*=== Little endian r/w ===*/

MEM_STATIC U16 MEM_readLE16(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_read16(memPtr);
    else {
        const BYTE* p = (const BYTE*)memPtr;
        return (U16)(p[0] + (p[1]<<8));
    }
}

MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
{
    if (MEM_isLittleEndian()) {
        MEM_write16(memPtr, val);
    } else {
        BYTE* p = (BYTE*)memPtr;
        p[0] = (BYTE)val;
        p[1] = (BYTE)(val>>8);
    }
}

MEM_STATIC U32 MEM_readLE24(const void* memPtr)
{
    return (U32)MEM_readLE16(memPtr) + ((U32)(((const BYTE*)memPtr)[2]) << 16);
}

MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val)
{
    MEM_writeLE16(memPtr, (U16)val);
    ((BYTE*)memPtr)[2] = (BYTE)(val>>16);
}

MEM_STATIC U32 MEM_readLE32(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_read32(memPtr);
    else
        return MEM_swap32(MEM_read32(memPtr));
}

MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32)
{
    if (MEM_isLittleEndian())
        MEM_write32(memPtr, val32);
    else
        MEM_write32(memPtr, MEM_swap32(val32));
}

MEM_STATIC U64 MEM_readLE64(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_read64(memPtr);
    else
        return MEM_swap64(MEM_read64(memPtr));
}

MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64)
{
    if (MEM_isLittleEndian())
        MEM_write64(memPtr, val64);
    else
        MEM_write64(memPtr, MEM_swap64(val64));
}

MEM_STATIC size_t MEM_readLEST(const void* memPtr)
{
    if (MEM_32bits())
        return (size_t)MEM_readLE32(memPtr);
    else
        return (size_t)MEM_readLE64(memPtr);
}

MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val)
{
    if (MEM_32bits())
        MEM_writeLE32(memPtr, (U32)val);
    else
        MEM_writeLE64(memPtr, (U64)val);
}

/*=== Big endian r/w ===*/

MEM_STATIC U32 MEM_readBE32(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_swap32(MEM_read32(memPtr));
    else
        return MEM_read32(memPtr);
}

MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32)
{
    if (MEM_isLittleEndian())
        MEM_write32(memPtr, MEM_swap32(val32));
    else
        MEM_write32(memPtr, val32);
}

MEM_STATIC U64 MEM_readBE64(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_swap64(MEM_read64(memPtr));
    else
        return MEM_read64(memPtr);
}

MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64)
{
    if (MEM_isLittleEndian())
        MEM_write64(memPtr, MEM_swap64(val64));
    else
        MEM_write64(memPtr, val64);
}

MEM_STATIC size_t MEM_readBEST(const void* memPtr)
{
    if (MEM_32bits())
        return (size_t)MEM_readBE32(memPtr);
    else
        return (size_t)MEM_readBE64(memPtr);
}

MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val)
{
    if (MEM_32bits())
        MEM_writeBE32(memPtr, (U32)val);
    else
        MEM_writeBE64(memPtr, (U64)val);
}

/* code only tested on 32 and 64 bits systems */
MEM_STATIC void MEM_check(void) { DEBUG_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); }


#if defined (__cplusplus)
}
#endif

#endif /* MEM_H_MODULE */
/**** ended inlining mem.h ****/
/**** start inlining error_private.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* Note : this module is expected to remain private, do not expose it */

#ifndef ERROR_H_MODULE
#define ERROR_H_MODULE

#if defined (__cplusplus)
extern "C" {
#endif


/* ****************************************
*  Dependencies
******************************************/
/**** start inlining ../zstd_errors.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_ERRORS_H_398273423
#define ZSTD_ERRORS_H_398273423

#if defined (__cplusplus)
extern "C" {
#endif

/*===== dependency =====*/
#include <stddef.h>   /* size_t */


/* =====   ZSTDERRORLIB_API : control library symbols visibility   ===== */
#ifndef ZSTDERRORLIB_VISIBLE
   /* Backwards compatibility with old macro name */
#  ifdef ZSTDERRORLIB_VISIBILITY
#    define ZSTDERRORLIB_VISIBLE ZSTDERRORLIB_VISIBILITY
#  elif defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
#    define ZSTDERRORLIB_VISIBLE __attribute__ ((visibility ("default")))
#  else
#    define ZSTDERRORLIB_VISIBLE
#  endif
#endif

#ifndef ZSTDERRORLIB_HIDDEN
#  if defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
#    define ZSTDERRORLIB_HIDDEN __attribute__ ((visibility ("hidden")))
#  else
#    define ZSTDERRORLIB_HIDDEN
#  endif
#endif

#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
#  define ZSTDERRORLIB_API __declspec(dllexport) ZSTDERRORLIB_VISIBLE
#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
#  define ZSTDERRORLIB_API __declspec(dllimport) ZSTDERRORLIB_VISIBLE /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
#else
#  define ZSTDERRORLIB_API ZSTDERRORLIB_VISIBLE
#endif

/*-*********************************************
 *  Error codes list
 *-*********************************************
 *  Error codes _values_ are pinned down since v1.3.1 only.
 *  Therefore, don't rely on values if you may link to any version < v1.3.1.
 *
 *  Only values < 100 are considered stable.
 *
 *  note 1 : this API shall be used with static linking only.
 *           dynamic linking is not yet officially supported.
 *  note 2 : Prefer relying on the enum than on its value whenever possible
 *           This is the only supported way to use the error list < v1.3.1
 *  note 3 : ZSTD_isError() is always correct, whatever the library version.
 **********************************************/
typedef enum {
  ZSTD_error_no_error = 0,
  ZSTD_error_GENERIC  = 1,
  ZSTD_error_prefix_unknown                = 10,
  ZSTD_error_version_unsupported           = 12,
  ZSTD_error_frameParameter_unsupported    = 14,
  ZSTD_error_frameParameter_windowTooLarge = 16,
  ZSTD_error_corruption_detected = 20,
  ZSTD_error_checksum_wrong      = 22,
  ZSTD_error_literals_headerWrong = 24,
  ZSTD_error_dictionary_corrupted      = 30,
  ZSTD_error_dictionary_wrong          = 32,
  ZSTD_error_dictionaryCreation_failed = 34,
  ZSTD_error_parameter_unsupported   = 40,
  ZSTD_error_parameter_combination_unsupported = 41,
  ZSTD_error_parameter_outOfBound    = 42,
  ZSTD_error_tableLog_tooLarge       = 44,
  ZSTD_error_maxSymbolValue_tooLarge = 46,
  ZSTD_error_maxSymbolValue_tooSmall = 48,
  ZSTD_error_stabilityCondition_notRespected = 50,
  ZSTD_error_stage_wrong       = 60,
  ZSTD_error_init_missing      = 62,
  ZSTD_error_memory_allocation = 64,
  ZSTD_error_workSpace_tooSmall= 66,
  ZSTD_error_dstSize_tooSmall = 70,
  ZSTD_error_srcSize_wrong    = 72,
  ZSTD_error_dstBuffer_null   = 74,
  ZSTD_error_noForwardProgress_destFull = 80,
  ZSTD_error_noForwardProgress_inputEmpty = 82,
  /* following error codes are __NOT STABLE__, they can be removed or changed in future versions */
  ZSTD_error_frameIndex_tooLarge = 100,
  ZSTD_error_seekableIO          = 102,
  ZSTD_error_dstBuffer_wrong     = 104,
  ZSTD_error_srcBuffer_wrong     = 105,
  ZSTD_error_sequenceProducer_failed = 106,
  ZSTD_error_externalSequences_invalid = 107,
  ZSTD_error_maxCode = 120  /* never EVER use this value directly, it can change in future versions! Use ZSTD_isError() instead */
} ZSTD_ErrorCode;

/*! ZSTD_getErrorCode() :
    convert a `size_t` function result into a `ZSTD_ErrorCode` enum type,
    which can be used to compare with enum list published above */
ZSTDERRORLIB_API ZSTD_ErrorCode ZSTD_getErrorCode(size_t functionResult);
ZSTDERRORLIB_API const char* ZSTD_getErrorString(ZSTD_ErrorCode code);   /**< Same as ZSTD_getErrorName, but using a `ZSTD_ErrorCode` enum argument */


#if defined (__cplusplus)
}
#endif

#endif /* ZSTD_ERRORS_H_398273423 */
/**** ended inlining ../zstd_errors.h ****/
/**** skipping file: compiler.h ****/
/**** skipping file: debug.h ****/
/**** skipping file: zstd_deps.h ****/


/* ****************************************
*  Compiler-specific
******************************************/
#if defined(__GNUC__)
#  define ERR_STATIC static __attribute__((unused))
#elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#  define ERR_STATIC static inline
#elif defined(_MSC_VER)
#  define ERR_STATIC static __inline
#else
#  define ERR_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
#endif


/*-****************************************
*  Customization (error_public.h)
******************************************/
typedef ZSTD_ErrorCode ERR_enum;
#define PREFIX(name) ZSTD_error_##name


/*-****************************************
*  Error codes handling
******************************************/
#undef ERROR   /* already defined on Visual Studio */
#define ERROR(name) ZSTD_ERROR(name)
#define ZSTD_ERROR(name) ((size_t)-PREFIX(name))

ERR_STATIC unsigned ERR_isError(size_t code) { return (code > ERROR(maxCode)); }

ERR_STATIC ERR_enum ERR_getErrorCode(size_t code) { if (!ERR_isError(code)) return (ERR_enum)0; return (ERR_enum) (0-code); }

/* check and forward error code */
#define CHECK_V_F(e, f)     \
    size_t const e = f;     \
    do {                    \
        if (ERR_isError(e)) \
            return e;       \
    } while (0)
#define CHECK_F(f)   do { CHECK_V_F(_var_err__, f); } while (0)


/*-****************************************
*  Error Strings
******************************************/

const char* ERR_getErrorString(ERR_enum code);   /* error_private.c */

ERR_STATIC const char* ERR_getErrorName(size_t code)
{
    return ERR_getErrorString(ERR_getErrorCode(code));
}

/**
 * Ignore: this is an internal helper.
 *
 * This is a helper function to help force C99-correctness during compilation.
 * Under strict compilation modes, variadic macro arguments can't be empty.
 * However, variadic function arguments can be. Using a function therefore lets
 * us statically check that at least one (string) argument was passed,
 * independent of the compilation flags.
 */
static INLINE_KEYWORD UNUSED_ATTR
void _force_has_format_string(const char *format, ...) {
  (void)format;
}

/**
 * Ignore: this is an internal helper.
 *
 * We want to force this function invocation to be syntactically correct, but
 * we don't want to force runtime evaluation of its arguments.
 */
#define _FORCE_HAS_FORMAT_STRING(...)              \
    do {                                           \
        if (0) {                                   \
            _force_has_format_string(__VA_ARGS__); \
        }                                          \
    } while (0)

#define ERR_QUOTE(str) #str

/**
 * Return the specified error if the condition evaluates to true.
 *
 * In debug modes, prints additional information.
 * In order to do that (particularly, printing the conditional that failed),
 * this can't just wrap RETURN_ERROR().
 */
#define RETURN_ERROR_IF(cond, err, ...)                                        \
    do {                                                                       \
        if (cond) {                                                            \
            RAWLOG(3, "%s:%d: ERROR!: check %s failed, returning %s",          \
                  __FILE__, __LINE__, ERR_QUOTE(cond), ERR_QUOTE(ERROR(err))); \
            _FORCE_HAS_FORMAT_STRING(__VA_ARGS__);                             \
            RAWLOG(3, ": " __VA_ARGS__);                                       \
            RAWLOG(3, "\n");                                                   \
            return ERROR(err);                                                 \
        }                                                                      \
    } while (0)

/**
 * Unconditionally return the specified error.
 *
 * In debug modes, prints additional information.
 */
#define RETURN_ERROR(err, ...)                                               \
    do {                                                                     \
        RAWLOG(3, "%s:%d: ERROR!: unconditional check failed, returning %s", \
              __FILE__, __LINE__, ERR_QUOTE(ERROR(err)));                    \
        _FORCE_HAS_FORMAT_STRING(__VA_ARGS__);                               \
        RAWLOG(3, ": " __VA_ARGS__);                                         \
        RAWLOG(3, "\n");                                                     \
        return ERROR(err);                                                   \
    } while(0)

/**
 * If the provided expression evaluates to an error code, returns that error code.
 *
 * In debug modes, prints additional information.
 */
#define FORWARD_IF_ERROR(err, ...)                                                 \
    do {                                                                           \
        size_t const err_code = (err);                                             \
        if (ERR_isError(err_code)) {                                               \
            RAWLOG(3, "%s:%d: ERROR!: forwarding error in %s: %s",                 \
                  __FILE__, __LINE__, ERR_QUOTE(err), ERR_getErrorName(err_code)); \
            _FORCE_HAS_FORMAT_STRING(__VA_ARGS__);                                 \
            RAWLOG(3, ": " __VA_ARGS__);                                           \
            RAWLOG(3, "\n");                                                       \
            return err_code;                                                       \
        }                                                                          \
    } while(0)

#if defined (__cplusplus)
}
#endif

#endif /* ERROR_H_MODULE */
/**** ended inlining error_private.h ****/
#define FSE_STATIC_LINKING_ONLY  /* FSE_MIN_TABLELOG */
/**** start inlining fse.h ****/
/* ******************************************************************
 * FSE : Finite State Entropy codec
 * Public Prototypes declaration
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * You can contact the author at :
 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */

#if defined (__cplusplus)
extern "C" {
#endif

#ifndef FSE_H
#define FSE_H


/*-*****************************************
*  Dependencies
******************************************/
/**** skipping file: zstd_deps.h ****/


/*-*****************************************
*  FSE_PUBLIC_API : control library symbols visibility
******************************************/
#if defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1) && defined(__GNUC__) && (__GNUC__ >= 4)
#  define FSE_PUBLIC_API __attribute__ ((visibility ("default")))
#elif defined(FSE_DLL_EXPORT) && (FSE_DLL_EXPORT==1)   /* Visual expected */
#  define FSE_PUBLIC_API __declspec(dllexport)
#elif defined(FSE_DLL_IMPORT) && (FSE_DLL_IMPORT==1)
#  define FSE_PUBLIC_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
#else
#  define FSE_PUBLIC_API
#endif

/*------   Version   ------*/
#define FSE_VERSION_MAJOR    0
#define FSE_VERSION_MINOR    9
#define FSE_VERSION_RELEASE  0

#define FSE_LIB_VERSION FSE_VERSION_MAJOR.FSE_VERSION_MINOR.FSE_VERSION_RELEASE
#define FSE_QUOTE(str) #str
#define FSE_EXPAND_AND_QUOTE(str) FSE_QUOTE(str)
#define FSE_VERSION_STRING FSE_EXPAND_AND_QUOTE(FSE_LIB_VERSION)

#define FSE_VERSION_NUMBER  (FSE_VERSION_MAJOR *100*100 + FSE_VERSION_MINOR *100 + FSE_VERSION_RELEASE)
FSE_PUBLIC_API unsigned FSE_versionNumber(void);   /**< library version number; to be used when checking dll version */


/*-*****************************************
*  Tool functions
******************************************/
FSE_PUBLIC_API size_t FSE_compressBound(size_t size);       /* maximum compressed size */

/* Error Management */
FSE_PUBLIC_API unsigned    FSE_isError(size_t code);        /* tells if a return value is an error code */
FSE_PUBLIC_API const char* FSE_getErrorName(size_t code);   /* provides error code string (useful for debugging) */


/*-*****************************************
*  FSE detailed API
******************************************/
/*!
FSE_compress() does the following:
1. count symbol occurrence from source[] into table count[] (see hist.h)
2. normalize counters so that sum(count[]) == Power_of_2 (2^tableLog)
3. save normalized counters to memory buffer using writeNCount()
4. build encoding table 'CTable' from normalized counters
5. encode the data stream using encoding table 'CTable'

FSE_decompress() does the following:
1. read normalized counters with readNCount()
2. build decoding table 'DTable' from normalized counters
3. decode the data stream using decoding table 'DTable'

The following API allows targeting specific sub-functions for advanced tasks.
For example, it's possible to compress several blocks using the same 'CTable',
or to save and provide normalized distribution using external method.
*/

/* *** COMPRESSION *** */

/*! FSE_optimalTableLog():
    dynamically downsize 'tableLog' when conditions are met.
    It saves CPU time, by using smaller tables, while preserving or even improving compression ratio.
    @return : recommended tableLog (necessarily <= 'maxTableLog') */
FSE_PUBLIC_API unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue);

/*! FSE_normalizeCount():
    normalize counts so that sum(count[]) == Power_of_2 (2^tableLog)
    'normalizedCounter' is a table of short, of minimum size (maxSymbolValue+1).
    useLowProbCount is a boolean parameter which trades off compressed size for
    faster header decoding. When it is set to 1, the compressed data will be slightly
    smaller. And when it is set to 0, FSE_readNCount() and FSE_buildDTable() will be
    faster. If you are compressing a small amount of data (< 2 KB) then useLowProbCount=0
    is a good default, since header deserialization makes a big speed difference.
    Otherwise, useLowProbCount=1 is a good default, since the speed difference is small.
    @return : tableLog,
              or an errorCode, which can be tested using FSE_isError() */
FSE_PUBLIC_API size_t FSE_normalizeCount(short* normalizedCounter, unsigned tableLog,
                    const unsigned* count, size_t srcSize, unsigned maxSymbolValue, unsigned useLowProbCount);

/*! FSE_NCountWriteBound():
    Provides the maximum possible size of an FSE normalized table, given 'maxSymbolValue' and 'tableLog'.
    Typically useful for allocation purpose. */
FSE_PUBLIC_API size_t FSE_NCountWriteBound(unsigned maxSymbolValue, unsigned tableLog);

/*! FSE_writeNCount():
    Compactly save 'normalizedCounter' into 'buffer'.
    @return : size of the compressed table,
              or an errorCode, which can be tested using FSE_isError(). */
FSE_PUBLIC_API size_t FSE_writeNCount (void* buffer, size_t bufferSize,
                                 const short* normalizedCounter,
                                 unsigned maxSymbolValue, unsigned tableLog);

/*! Constructor and Destructor of FSE_CTable.
    Note that FSE_CTable size depends on 'tableLog' and 'maxSymbolValue' */
typedef unsigned FSE_CTable;   /* don't allocate that. It's only meant to be more restrictive than void* */

/*! FSE_buildCTable():
    Builds `ct`, which must be already allocated, using FSE_createCTable().
    @return : 0, or an errorCode, which can be tested using FSE_isError() */
FSE_PUBLIC_API size_t FSE_buildCTable(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);

/*! FSE_compress_usingCTable():
    Compress `src` using `ct` into `dst` which must be already allocated.
    @return : size of compressed data (<= `dstCapacity`),
              or 0 if compressed data could not fit into `dst`,
              or an errorCode, which can be tested using FSE_isError() */
FSE_PUBLIC_API size_t FSE_compress_usingCTable (void* dst, size_t dstCapacity, const void* src, size_t srcSize, const FSE_CTable* ct);

/*!
Tutorial :
----------
The first step is to count all symbols. FSE_count() does this job very fast.
Result will be saved into 'count', a table of unsigned int, which must be already allocated, and have 'maxSymbolValuePtr[0]+1' cells.
'src' is a table of bytes of size 'srcSize'. All values within 'src' MUST be <= maxSymbolValuePtr[0]
maxSymbolValuePtr[0] will be updated, with its real value (necessarily <= original value)
FSE_count() will return the number of occurrence of the most frequent symbol.
This can be used to know if there is a single symbol within 'src', and to quickly evaluate its compressibility.
If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).

The next step is to normalize the frequencies.
FSE_normalizeCount() will ensure that sum of frequencies is == 2 ^'tableLog'.
It also guarantees a minimum of 1 to any Symbol with frequency >= 1.
You can use 'tableLog'==0 to mean "use default tableLog value".
If you are unsure of which tableLog value to use, you can ask FSE_optimalTableLog(),
which will provide the optimal valid tableLog given sourceSize, maxSymbolValue, and a user-defined maximum (0 means "default").

The result of FSE_normalizeCount() will be saved into a table,
called 'normalizedCounter', which is a table of signed short.
'normalizedCounter' must be already allocated, and have at least 'maxSymbolValue+1' cells.
The return value is tableLog if everything proceeded as expected.
It is 0 if there is a single symbol within distribution.
If there is an error (ex: invalid tableLog value), the function will return an ErrorCode (which can be tested using FSE_isError()).

'normalizedCounter' can be saved in a compact manner to a memory area using FSE_writeNCount().
'buffer' must be already allocated.
For guaranteed success, buffer size must be at least FSE_headerBound().
The result of the function is the number of bytes written into 'buffer'.
If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError(); ex : buffer size too small).

'normalizedCounter' can then be used to create the compression table 'CTable'.
The space required by 'CTable' must be already allocated, using FSE_createCTable().
You can then use FSE_buildCTable() to fill 'CTable'.
If there is an error, both functions will return an ErrorCode (which can be tested using FSE_isError()).

'CTable' can then be used to compress 'src', with FSE_compress_usingCTable().
Similar to FSE_count(), the convention is that 'src' is assumed to be a table of char of size 'srcSize'
The function returns the size of compressed data (without header), necessarily <= `dstCapacity`.
If it returns '0', compressed data could not fit into 'dst'.
If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).
*/


/* *** DECOMPRESSION *** */

/*! FSE_readNCount():
    Read compactly saved 'normalizedCounter' from 'rBuffer'.
    @return : size read from 'rBuffer',
              or an errorCode, which can be tested using FSE_isError().
              maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
FSE_PUBLIC_API size_t FSE_readNCount (short* normalizedCounter,
                           unsigned* maxSymbolValuePtr, unsigned* tableLogPtr,
                           const void* rBuffer, size_t rBuffSize);

/*! FSE_readNCount_bmi2():
 * Same as FSE_readNCount() but pass bmi2=1 when your CPU supports BMI2 and 0 otherwise.
 */
FSE_PUBLIC_API size_t FSE_readNCount_bmi2(short* normalizedCounter,
                           unsigned* maxSymbolValuePtr, unsigned* tableLogPtr,
                           const void* rBuffer, size_t rBuffSize, int bmi2);

typedef unsigned FSE_DTable;   /* don't allocate that. It's just a way to be more restrictive than void* */

/*!
Tutorial :
----------
(Note : these functions only decompress FSE-compressed blocks.
 If block is uncompressed, use memcpy() instead
 If block is a single repeated byte, use memset() instead )

The first step is to obtain the normalized frequencies of symbols.
This can be performed by FSE_readNCount() if it was saved using FSE_writeNCount().
'normalizedCounter' must be already allocated, and have at least 'maxSymbolValuePtr[0]+1' cells of signed short.
In practice, that means it's necessary to know 'maxSymbolValue' beforehand,
or size the table to handle worst case situations (typically 256).
FSE_readNCount() will provide 'tableLog' and 'maxSymbolValue'.
The result of FSE_readNCount() is the number of bytes read from 'rBuffer'.
Note that 'rBufferSize' must be at least 4 bytes, even if useful information is less than that.
If there is an error, the function will return an error code, which can be tested using FSE_isError().

The next step is to build the decompression tables 'FSE_DTable' from 'normalizedCounter'.
This is performed by the function FSE_buildDTable().
The space required by 'FSE_DTable' must be already allocated using FSE_createDTable().
If there is an error, the function will return an error code, which can be tested using FSE_isError().

`FSE_DTable` can then be used to decompress `cSrc`, with FSE_decompress_usingDTable().
`cSrcSize` must be strictly correct, otherwise decompression will fail.
FSE_decompress_usingDTable() result will tell how many bytes were regenerated (<=`dstCapacity`).
If there is an error, the function will return an error code, which can be tested using FSE_isError(). (ex: dst buffer too small)
*/

#endif  /* FSE_H */


#if defined(FSE_STATIC_LINKING_ONLY) && !defined(FSE_H_FSE_STATIC_LINKING_ONLY)
#define FSE_H_FSE_STATIC_LINKING_ONLY

/* *** Dependency *** */
/**** start inlining bitstream.h ****/
/* ******************************************************************
 * bitstream
 * Part of FSE library
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * You can contact the author at :
 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */
#ifndef BITSTREAM_H_MODULE
#define BITSTREAM_H_MODULE

#if defined (__cplusplus)
extern "C" {
#endif
/*
*  This API consists of small unitary functions, which must be inlined for best performance.
*  Since link-time-optimization is not available for all compilers,
*  these functions are defined into a .h to be included.
*/

/*-****************************************
*  Dependencies
******************************************/
/**** skipping file: mem.h ****/
/**** skipping file: compiler.h ****/
/**** skipping file: debug.h ****/
/**** skipping file: error_private.h ****/
/**** start inlining bits.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_BITS_H
#define ZSTD_BITS_H

/**** skipping file: mem.h ****/

MEM_STATIC unsigned ZSTD_countTrailingZeros32_fallback(U32 val)
{
    assert(val != 0);
    {
        static const U32 DeBruijnBytePos[32] = {0, 1, 28, 2, 29, 14, 24, 3,
                                                30, 22, 20, 15, 25, 17, 4, 8,
                                                31, 27, 13, 23, 21, 19, 16, 7,
                                                26, 12, 18, 6, 11, 5, 10, 9};
        return DeBruijnBytePos[((U32) ((val & -(S32) val) * 0x077CB531U)) >> 27];
    }
}

MEM_STATIC unsigned ZSTD_countTrailingZeros32(U32 val)
{
    assert(val != 0);
#   if defined(_MSC_VER)
#       if STATIC_BMI2 == 1
            return (unsigned)_tzcnt_u32(val);
#       else
            if (val != 0) {
                unsigned long r;
                _BitScanForward(&r, val);
                return (unsigned)r;
            } else {
                /* Should not reach this code path */
                __assume(0);
            }
#       endif
#   elif defined(__GNUC__) && (__GNUC__ >= 4)
        return (unsigned)__builtin_ctz(val);
#   else
        return ZSTD_countTrailingZeros32_fallback(val);
#   endif
}

MEM_STATIC unsigned ZSTD_countLeadingZeros32_fallback(U32 val) {
    assert(val != 0);
    {
        static const U32 DeBruijnClz[32] = {0, 9, 1, 10, 13, 21, 2, 29,
                                            11, 14, 16, 18, 22, 25, 3, 30,
                                            8, 12, 20, 28, 15, 17, 24, 7,
                                            19, 27, 23, 6, 26, 5, 4, 31};
        val |= val >> 1;
        val |= val >> 2;
        val |= val >> 4;
        val |= val >> 8;
        val |= val >> 16;
        return 31 - DeBruijnClz[(val * 0x07C4ACDDU) >> 27];
    }
}

MEM_STATIC unsigned ZSTD_countLeadingZeros32(U32 val)
{
    assert(val != 0);
#   if defined(_MSC_VER)
#       if STATIC_BMI2 == 1
            return (unsigned)_lzcnt_u32(val);
#       else
            if (val != 0) {
                unsigned long r;
                _BitScanReverse(&r, val);
                return (unsigned)(31 - r);
            } else {
                /* Should not reach this code path */
                __assume(0);
            }
#       endif
#   elif defined(__GNUC__) && (__GNUC__ >= 4)
        return (unsigned)__builtin_clz(val);
#   else
        return ZSTD_countLeadingZeros32_fallback(val);
#   endif
}

MEM_STATIC unsigned ZSTD_countTrailingZeros64(U64 val)
{
    assert(val != 0);
#   if defined(_MSC_VER) && defined(_WIN64)
#       if STATIC_BMI2 == 1
            return (unsigned)_tzcnt_u64(val);
#       else
            if (val != 0) {
                unsigned long r;
                _BitScanForward64(&r, val);
                return (unsigned)r;
            } else {
                /* Should not reach this code path */
                __assume(0);
            }
#       endif
#   elif defined(__GNUC__) && (__GNUC__ >= 4) && defined(__LP64__)
        return (unsigned)__builtin_ctzll(val);
#   else
        {
            U32 mostSignificantWord = (U32)(val >> 32);
            U32 leastSignificantWord = (U32)val;
            if (leastSignificantWord == 0) {
                return 32 + ZSTD_countTrailingZeros32(mostSignificantWord);
            } else {
                return ZSTD_countTrailingZeros32(leastSignificantWord);
            }
        }
#   endif
}

MEM_STATIC unsigned ZSTD_countLeadingZeros64(U64 val)
{
    assert(val != 0);
#   if defined(_MSC_VER) && defined(_WIN64)
#       if STATIC_BMI2 == 1
            return (unsigned)_lzcnt_u64(val);
#       else
            if (val != 0) {
                unsigned long r;
                _BitScanReverse64(&r, val);
                return (unsigned)(63 - r);
            } else {
                /* Should not reach this code path */
                __assume(0);
            }
#       endif
#   elif defined(__GNUC__) && (__GNUC__ >= 4)
        return (unsigned)(__builtin_clzll(val));
#   else
        {
            U32 mostSignificantWord = (U32)(val >> 32);
            U32 leastSignificantWord = (U32)val;
            if (mostSignificantWord == 0) {
                return 32 + ZSTD_countLeadingZeros32(leastSignificantWord);
            } else {
                return ZSTD_countLeadingZeros32(mostSignificantWord);
            }
        }
#   endif
}

MEM_STATIC unsigned ZSTD_NbCommonBytes(size_t val)
{
    if (MEM_isLittleEndian()) {
        if (MEM_64bits()) {
            return ZSTD_countTrailingZeros64((U64)val) >> 3;
        } else {
            return ZSTD_countTrailingZeros32((U32)val) >> 3;
        }
    } else {  /* Big Endian CPU */
        if (MEM_64bits()) {
            return ZSTD_countLeadingZeros64((U64)val) >> 3;
        } else {
            return ZSTD_countLeadingZeros32((U32)val) >> 3;
        }
    }
}

MEM_STATIC unsigned ZSTD_highbit32(U32 val)   /* compress, dictBuilder, decodeCorpus */
{
    assert(val != 0);
    return 31 - ZSTD_countLeadingZeros32(val);
}

/* ZSTD_rotateRight_*():
 * Rotates a bitfield to the right by "count" bits.
 * https://en.wikipedia.org/w/index.php?title=Circular_shift&oldid=991635599#Implementing_circular_shifts
 */
MEM_STATIC
U64 ZSTD_rotateRight_U64(U64 const value, U32 count) {
    assert(count < 64);
    count &= 0x3F; /* for fickle pattern recognition */
    return (value >> count) | (U64)(value << ((0U - count) & 0x3F));
}

MEM_STATIC
U32 ZSTD_rotateRight_U32(U32 const value, U32 count) {
    assert(count < 32);
    count &= 0x1F; /* for fickle pattern recognition */
    return (value >> count) | (U32)(value << ((0U - count) & 0x1F));
}

MEM_STATIC
U16 ZSTD_rotateRight_U16(U16 const value, U32 count) {
    assert(count < 16);
    count &= 0x0F; /* for fickle pattern recognition */
    return (value >> count) | (U16)(value << ((0U - count) & 0x0F));
}

#endif /* ZSTD_BITS_H */
/**** ended inlining bits.h ****/


/*=========================================
*  Target specific
=========================================*/
#ifndef ZSTD_NO_INTRINSICS
#  if (defined(__BMI__) || defined(__BMI2__)) && defined(__GNUC__)
#    include <immintrin.h>   /* support for bextr (experimental)/bzhi */
#  elif defined(__ICCARM__)
#    include <intrinsics.h>
#  endif
#endif

#define STREAM_ACCUMULATOR_MIN_32  25
#define STREAM_ACCUMULATOR_MIN_64  57
#define STREAM_ACCUMULATOR_MIN    ((U32)(MEM_32bits() ? STREAM_ACCUMULATOR_MIN_32 : STREAM_ACCUMULATOR_MIN_64))


/*-******************************************
*  bitStream encoding API (write forward)
********************************************/
/* bitStream can mix input from multiple sources.
 * A critical property of these streams is that they encode and decode in **reverse** direction.
 * So the first bit sequence you add will be the last to be read, like a LIFO stack.
 */
typedef struct {
    size_t bitContainer;
    unsigned bitPos;
    char*  startPtr;
    char*  ptr;
    char*  endPtr;
} BIT_CStream_t;

MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC, void* dstBuffer, size_t dstCapacity);
MEM_STATIC void   BIT_addBits(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
MEM_STATIC void   BIT_flushBits(BIT_CStream_t* bitC);
MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC);

/* Start with initCStream, providing the size of buffer to write into.
*  bitStream will never write outside of this buffer.
*  `dstCapacity` must be >= sizeof(bitD->bitContainer), otherwise @return will be an error code.
*
*  bits are first added to a local register.
*  Local register is size_t, hence 64-bits on 64-bits systems, or 32-bits on 32-bits systems.
*  Writing data into memory is an explicit operation, performed by the flushBits function.
*  Hence keep track how many bits are potentially stored into local register to avoid register overflow.
*  After a flushBits, a maximum of 7 bits might still be stored into local register.
*
*  Avoid storing elements of more than 24 bits if you want compatibility with 32-bits bitstream readers.
*
*  Last operation is to close the bitStream.
*  The function returns the final size of CStream in bytes.
*  If data couldn't fit into `dstBuffer`, it will return a 0 ( == not storable)
*/


/*-********************************************
*  bitStream decoding API (read backward)
**********************************************/
typedef size_t BitContainerType;
typedef struct {
    BitContainerType bitContainer;
    unsigned bitsConsumed;
    const char* ptr;
    const char* start;
    const char* limitPtr;
} BIT_DStream_t;

typedef enum { BIT_DStream_unfinished = 0,  /* fully refilled */
               BIT_DStream_endOfBuffer = 1, /* still some bits left in bitstream */
               BIT_DStream_completed = 2,   /* bitstream entirely consumed, bit-exact */
               BIT_DStream_overflow = 3     /* user requested more bits than present in bitstream */
    } BIT_DStream_status;  /* result of BIT_reloadDStream() */

MEM_STATIC size_t   BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize);
MEM_STATIC size_t   BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits);
MEM_STATIC BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD);
MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* bitD);


/* Start by invoking BIT_initDStream().
*  A chunk of the bitStream is then stored into a local register.
*  Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (BitContainerType).
*  You can then retrieve bitFields stored into the local register, **in reverse order**.
*  Local register is explicitly reloaded from memory by the BIT_reloadDStream() method.
*  A reload guarantee a minimum of ((8*sizeof(bitD->bitContainer))-7) bits when its result is BIT_DStream_unfinished.
*  Otherwise, it can be less than that, so proceed accordingly.
*  Checking if DStream has reached its end can be performed with BIT_endOfDStream().
*/


/*-****************************************
*  unsafe API
******************************************/
MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC, size_t value, unsigned nbBits);
/* faster, but works only if value is "clean", meaning all high bits above nbBits are 0 */

MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC);
/* unsafe version; does not check buffer overflow */

MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits);
/* faster, but works only if nbBits >= 1 */

/*=====    Local Constants   =====*/
static const unsigned BIT_mask[] = {
    0,          1,         3,         7,         0xF,       0x1F,
    0x3F,       0x7F,      0xFF,      0x1FF,     0x3FF,     0x7FF,
    0xFFF,      0x1FFF,    0x3FFF,    0x7FFF,    0xFFFF,    0x1FFFF,
    0x3FFFF,    0x7FFFF,   0xFFFFF,   0x1FFFFF,  0x3FFFFF,  0x7FFFFF,
    0xFFFFFF,   0x1FFFFFF, 0x3FFFFFF, 0x7FFFFFF, 0xFFFFFFF, 0x1FFFFFFF,
    0x3FFFFFFF, 0x7FFFFFFF}; /* up to 31 bits */
#define BIT_MASK_SIZE (sizeof(BIT_mask) / sizeof(BIT_mask[0]))

/*-**************************************************************
*  bitStream encoding
****************************************************************/
/*! BIT_initCStream() :
 *  `dstCapacity` must be > sizeof(size_t)
 *  @return : 0 if success,
 *            otherwise an error code (can be tested using ERR_isError()) */
MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC,
                                  void* startPtr, size_t dstCapacity)
{
    bitC->bitContainer = 0;
    bitC->bitPos = 0;
    bitC->startPtr = (char*)startPtr;
    bitC->ptr = bitC->startPtr;
    bitC->endPtr = bitC->startPtr + dstCapacity - sizeof(bitC->bitContainer);
    if (dstCapacity <= sizeof(bitC->bitContainer)) return ERROR(dstSize_tooSmall);
    return 0;
}

FORCE_INLINE_TEMPLATE size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
{
#if defined(STATIC_BMI2) && STATIC_BMI2 == 1 && !defined(ZSTD_NO_INTRINSICS)
    return  _bzhi_u64(bitContainer, nbBits);
#else
    assert(nbBits < BIT_MASK_SIZE);
    return bitContainer & BIT_mask[nbBits];
#endif
}

/*! BIT_addBits() :
 *  can add up to 31 bits into `bitC`.
 *  Note : does not check for register overflow ! */
MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
                            size_t value, unsigned nbBits)
{
    DEBUG_STATIC_ASSERT(BIT_MASK_SIZE == 32);
    assert(nbBits < BIT_MASK_SIZE);
    assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
    bitC->bitContainer |= BIT_getLowerBits(value, nbBits) << bitC->bitPos;
    bitC->bitPos += nbBits;
}

/*! BIT_addBitsFast() :
 *  works only if `value` is _clean_,
 *  meaning all high bits above nbBits are 0 */
MEM_STATIC void BIT_addBitsFast(BIT_CStream_t* bitC,
                                size_t value, unsigned nbBits)
{
    assert((value>>nbBits) == 0);
    assert(nbBits + bitC->bitPos < sizeof(bitC->bitContainer) * 8);
    bitC->bitContainer |= value << bitC->bitPos;
    bitC->bitPos += nbBits;
}

/*! BIT_flushBitsFast() :
 *  assumption : bitContainer has not overflowed
 *  unsafe version; does not check buffer overflow */
MEM_STATIC void BIT_flushBitsFast(BIT_CStream_t* bitC)
{
    size_t const nbBytes = bitC->bitPos >> 3;
    assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
    assert(bitC->ptr <= bitC->endPtr);
    MEM_writeLEST(bitC->ptr, bitC->bitContainer);
    bitC->ptr += nbBytes;
    bitC->bitPos &= 7;
    bitC->bitContainer >>= nbBytes*8;
}

/*! BIT_flushBits() :
 *  assumption : bitContainer has not overflowed
 *  safe version; check for buffer overflow, and prevents it.
 *  note : does not signal buffer overflow.
 *  overflow will be revealed later on using BIT_closeCStream() */
MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
{
    size_t const nbBytes = bitC->bitPos >> 3;
    assert(bitC->bitPos < sizeof(bitC->bitContainer) * 8);
    assert(bitC->ptr <= bitC->endPtr);
    MEM_writeLEST(bitC->ptr, bitC->bitContainer);
    bitC->ptr += nbBytes;
    if (bitC->ptr > bitC->endPtr) bitC->ptr = bitC->endPtr;
    bitC->bitPos &= 7;
    bitC->bitContainer >>= nbBytes*8;
}

/*! BIT_closeCStream() :
 *  @return : size of CStream, in bytes,
 *            or 0 if it could not fit into dstBuffer */
MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
{
    BIT_addBitsFast(bitC, 1, 1);   /* endMark */
    BIT_flushBits(bitC);
    if (bitC->ptr >= bitC->endPtr) return 0; /* overflow detected */
    return (bitC->ptr - bitC->startPtr) + (bitC->bitPos > 0);
}


/*-********************************************************
*  bitStream decoding
**********************************************************/
/*! BIT_initDStream() :
 *  Initialize a BIT_DStream_t.
 * `bitD` : a pointer to an already allocated BIT_DStream_t structure.
 * `srcSize` must be the *exact* size of the bitStream, in bytes.
 * @return : size of stream (== srcSize), or an errorCode if a problem is detected
 */
MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
{
    if (srcSize < 1) { ZSTD_memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }

    bitD->start = (const char*)srcBuffer;
    bitD->limitPtr = bitD->start + sizeof(bitD->bitContainer);

    if (srcSize >=  sizeof(bitD->bitContainer)) {  /* normal case */
        bitD->ptr   = (const char*)srcBuffer + srcSize - sizeof(bitD->bitContainer);
        bitD->bitContainer = MEM_readLEST(bitD->ptr);
        { BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
          bitD->bitsConsumed = lastByte ? 8 - ZSTD_highbit32(lastByte) : 0;  /* ensures bitsConsumed is always set */
          if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
    } else {
        bitD->ptr   = bitD->start;
        bitD->bitContainer = *(const BYTE*)(bitD->start);
        switch(srcSize)
        {
        case 7: bitD->bitContainer += (BitContainerType)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);
                ZSTD_FALLTHROUGH;

        case 6: bitD->bitContainer += (BitContainerType)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
                ZSTD_FALLTHROUGH;

        case 5: bitD->bitContainer += (BitContainerType)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
                ZSTD_FALLTHROUGH;

        case 4: bitD->bitContainer += (BitContainerType)(((const BYTE*)(srcBuffer))[3]) << 24;
                ZSTD_FALLTHROUGH;

        case 3: bitD->bitContainer += (BitContainerType)(((const BYTE*)(srcBuffer))[2]) << 16;
                ZSTD_FALLTHROUGH;

        case 2: bitD->bitContainer += (BitContainerType)(((const BYTE*)(srcBuffer))[1]) <<  8;
                ZSTD_FALLTHROUGH;

        default: break;
        }
        {   BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
            bitD->bitsConsumed = lastByte ? 8 - ZSTD_highbit32(lastByte) : 0;
            if (lastByte == 0) return ERROR(corruption_detected);  /* endMark not present */
        }
        bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize)*8;
    }

    return srcSize;
}

FORCE_INLINE_TEMPLATE size_t BIT_getUpperBits(BitContainerType bitContainer, U32 const start)
{
    return bitContainer >> start;
}

FORCE_INLINE_TEMPLATE size_t BIT_getMiddleBits(BitContainerType bitContainer, U32 const start, U32 const nbBits)
{
    U32 const regMask = sizeof(bitContainer)*8 - 1;
    /* if start > regMask, bitstream is corrupted, and result is undefined */
    assert(nbBits < BIT_MASK_SIZE);
    /* x86 transform & ((1 << nbBits) - 1) to bzhi instruction, it is better
     * than accessing memory. When bmi2 instruction is not present, we consider
     * such cpus old (pre-Haswell, 2013) and their performance is not of that
     * importance.
     */
#if defined(__x86_64__) || defined(_M_X86)
    return (bitContainer >> (start & regMask)) & ((((U64)1) << nbBits) - 1);
#else
    return (bitContainer >> (start & regMask)) & BIT_mask[nbBits];
#endif
}

/*! BIT_lookBits() :
 *  Provides next n bits from local register.
 *  local register is not modified.
 *  On 32-bits, maxNbBits==24.
 *  On 64-bits, maxNbBits==56.
 * @return : value extracted */
FORCE_INLINE_TEMPLATE size_t BIT_lookBits(const BIT_DStream_t*  bitD, U32 nbBits)
{
    /* arbitrate between double-shift and shift+mask */
#if 1
    /* if bitD->bitsConsumed + nbBits > sizeof(bitD->bitContainer)*8,
     * bitstream is likely corrupted, and result is undefined */
    return BIT_getMiddleBits(bitD->bitContainer, (sizeof(bitD->bitContainer)*8) - bitD->bitsConsumed - nbBits, nbBits);
#else
    /* this code path is slower on my os-x laptop */
    U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
    return ((bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> 1) >> ((regMask-nbBits) & regMask);
#endif
}

/*! BIT_lookBitsFast() :
 *  unsafe version; only works if nbBits >= 1 */
MEM_STATIC size_t BIT_lookBitsFast(const BIT_DStream_t* bitD, U32 nbBits)
{
    U32 const regMask = sizeof(bitD->bitContainer)*8 - 1;
    assert(nbBits >= 1);
    return (bitD->bitContainer << (bitD->bitsConsumed & regMask)) >> (((regMask+1)-nbBits) & regMask);
}

FORCE_INLINE_TEMPLATE void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
{
    bitD->bitsConsumed += nbBits;
}

/*! BIT_readBits() :
 *  Read (consume) next n bits from local register and update.
 *  Pay attention to not read more than nbBits contained into local register.
 * @return : extracted value. */
FORCE_INLINE_TEMPLATE size_t BIT_readBits(BIT_DStream_t* bitD, unsigned nbBits)
{
    size_t const value = BIT_lookBits(bitD, nbBits);
    BIT_skipBits(bitD, nbBits);
    return value;
}

/*! BIT_readBitsFast() :
 *  unsafe version; only works if nbBits >= 1 */
MEM_STATIC size_t BIT_readBitsFast(BIT_DStream_t* bitD, unsigned nbBits)
{
    size_t const value = BIT_lookBitsFast(bitD, nbBits);
    assert(nbBits >= 1);
    BIT_skipBits(bitD, nbBits);
    return value;
}

/*! BIT_reloadDStream_internal() :
 *  Simple variant of BIT_reloadDStream(), with two conditions:
 *  1. bitstream is valid : bitsConsumed <= sizeof(bitD->bitContainer)*8
 *  2. look window is valid after shifted down : bitD->ptr >= bitD->start
 */
MEM_STATIC BIT_DStream_status BIT_reloadDStream_internal(BIT_DStream_t* bitD)
{
    assert(bitD->bitsConsumed <= sizeof(bitD->bitContainer)*8);
    bitD->ptr -= bitD->bitsConsumed >> 3;
    assert(bitD->ptr >= bitD->start);
    bitD->bitsConsumed &= 7;
    bitD->bitContainer = MEM_readLEST(bitD->ptr);
    return BIT_DStream_unfinished;
}

/*! BIT_reloadDStreamFast() :
 *  Similar to BIT_reloadDStream(), but with two differences:
 *  1. bitsConsumed <= sizeof(bitD->bitContainer)*8 must hold!
 *  2. Returns BIT_DStream_overflow when bitD->ptr < bitD->limitPtr, at this
 *     point you must use BIT_reloadDStream() to reload.
 */
MEM_STATIC BIT_DStream_status BIT_reloadDStreamFast(BIT_DStream_t* bitD)
{
    if (UNLIKELY(bitD->ptr < bitD->limitPtr))
        return BIT_DStream_overflow;
    return BIT_reloadDStream_internal(bitD);
}

/*! BIT_reloadDStream() :
 *  Refill `bitD` from buffer previously set in BIT_initDStream() .
 *  This function is safe, it guarantees it will not never beyond src buffer.
 * @return : status of `BIT_DStream_t` internal register.
 *           when status == BIT_DStream_unfinished, internal register is filled with at least 25 or 57 bits */
FORCE_INLINE_TEMPLATE BIT_DStream_status BIT_reloadDStream(BIT_DStream_t* bitD)
{
    /* note : once in overflow mode, a bitstream remains in this mode until it's reset */
    if (UNLIKELY(bitD->bitsConsumed > (sizeof(bitD->bitContainer)*8))) {
        static const BitContainerType zeroFilled = 0;
        bitD->ptr = (const char*)&zeroFilled; /* aliasing is allowed for char */
        /* overflow detected, erroneous scenario or end of stream: no update */
        return BIT_DStream_overflow;
    }

    assert(bitD->ptr >= bitD->start);

    if (bitD->ptr >= bitD->limitPtr) {
        return BIT_reloadDStream_internal(bitD);
    }
    if (bitD->ptr == bitD->start) {
        /* reached end of bitStream => no update */
        if (bitD->bitsConsumed < sizeof(bitD->bitContainer)*8) return BIT_DStream_endOfBuffer;
        return BIT_DStream_completed;
    }
    /* start < ptr < limitPtr => cautious update */
    {   U32 nbBytes = bitD->bitsConsumed >> 3;
        BIT_DStream_status result = BIT_DStream_unfinished;
        if (bitD->ptr - nbBytes < bitD->start) {
            nbBytes = (U32)(bitD->ptr - bitD->start);  /* ptr > start */
            result = BIT_DStream_endOfBuffer;
        }
        bitD->ptr -= nbBytes;
        bitD->bitsConsumed -= nbBytes*8;
        bitD->bitContainer = MEM_readLEST(bitD->ptr);   /* reminder : srcSize > sizeof(bitD->bitContainer), otherwise bitD->ptr == bitD->start */
        return result;
    }
}

/*! BIT_endOfDStream() :
 * @return : 1 if DStream has _exactly_ reached its end (all bits consumed).
 */
MEM_STATIC unsigned BIT_endOfDStream(const BIT_DStream_t* DStream)
{
    return ((DStream->ptr == DStream->start) && (DStream->bitsConsumed == sizeof(DStream->bitContainer)*8));
}

#if defined (__cplusplus)
}
#endif

#endif /* BITSTREAM_H_MODULE */
/**** ended inlining bitstream.h ****/


/* *****************************************
*  Static allocation
*******************************************/
/* FSE buffer bounds */
#define FSE_NCOUNTBOUND 512
#define FSE_BLOCKBOUND(size) ((size) + ((size)>>7) + 4 /* fse states */ + sizeof(size_t) /* bitContainer */)
#define FSE_COMPRESSBOUND(size) (FSE_NCOUNTBOUND + FSE_BLOCKBOUND(size))   /* Macro version, useful for static allocation */

/* It is possible to statically allocate FSE CTable/DTable as a table of FSE_CTable/FSE_DTable using below macros */
#define FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue)   (1 + (1<<((maxTableLog)-1)) + (((maxSymbolValue)+1)*2))
#define FSE_DTABLE_SIZE_U32(maxTableLog)                   (1 + (1<<(maxTableLog)))

/* or use the size to malloc() space directly. Pay attention to alignment restrictions though */
#define FSE_CTABLE_SIZE(maxTableLog, maxSymbolValue)   (FSE_CTABLE_SIZE_U32(maxTableLog, maxSymbolValue) * sizeof(FSE_CTable))
#define FSE_DTABLE_SIZE(maxTableLog)                   (FSE_DTABLE_SIZE_U32(maxTableLog) * sizeof(FSE_DTable))


/* *****************************************
 *  FSE advanced API
 ***************************************** */

unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus);
/**< same as FSE_optimalTableLog(), which used `minus==2` */

size_t FSE_buildCTable_rle (FSE_CTable* ct, unsigned char symbolValue);
/**< build a fake FSE_CTable, designed to compress always the same symbolValue */

/* FSE_buildCTable_wksp() :
 * Same as FSE_buildCTable(), but using an externally allocated scratch buffer (`workSpace`).
 * `wkspSize` must be >= `FSE_BUILD_CTABLE_WORKSPACE_SIZE_U32(maxSymbolValue, tableLog)` of `unsigned`.
 * See FSE_buildCTable_wksp() for breakdown of workspace usage.
 */
#define FSE_BUILD_CTABLE_WORKSPACE_SIZE_U32(maxSymbolValue, tableLog) (((maxSymbolValue + 2) + (1ull << (tableLog)))/2 + sizeof(U64)/sizeof(U32) /* additional 8 bytes for potential table overwrite */)
#define FSE_BUILD_CTABLE_WORKSPACE_SIZE(maxSymbolValue, tableLog) (sizeof(unsigned) * FSE_BUILD_CTABLE_WORKSPACE_SIZE_U32(maxSymbolValue, tableLog))
size_t FSE_buildCTable_wksp(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize);

#define FSE_BUILD_DTABLE_WKSP_SIZE(maxTableLog, maxSymbolValue) (sizeof(short) * (maxSymbolValue + 1) + (1ULL << maxTableLog) + 8)
#define FSE_BUILD_DTABLE_WKSP_SIZE_U32(maxTableLog, maxSymbolValue) ((FSE_BUILD_DTABLE_WKSP_SIZE(maxTableLog, maxSymbolValue) + sizeof(unsigned) - 1) / sizeof(unsigned))
FSE_PUBLIC_API size_t FSE_buildDTable_wksp(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize);
/**< Same as FSE_buildDTable(), using an externally allocated `workspace` produced with `FSE_BUILD_DTABLE_WKSP_SIZE_U32(maxSymbolValue)` */

#define FSE_DECOMPRESS_WKSP_SIZE_U32(maxTableLog, maxSymbolValue) (FSE_DTABLE_SIZE_U32(maxTableLog) + 1 + FSE_BUILD_DTABLE_WKSP_SIZE_U32(maxTableLog, maxSymbolValue) + (FSE_MAX_SYMBOL_VALUE + 1) / 2 + 1)
#define FSE_DECOMPRESS_WKSP_SIZE(maxTableLog, maxSymbolValue) (FSE_DECOMPRESS_WKSP_SIZE_U32(maxTableLog, maxSymbolValue) * sizeof(unsigned))
size_t FSE_decompress_wksp_bmi2(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, unsigned maxLog, void* workSpace, size_t wkspSize, int bmi2);
/**< same as FSE_decompress(), using an externally allocated `workSpace` produced with `FSE_DECOMPRESS_WKSP_SIZE_U32(maxLog, maxSymbolValue)`.
 * Set bmi2 to 1 if your CPU supports BMI2 or 0 if it doesn't */

typedef enum {
   FSE_repeat_none,  /**< Cannot use the previous table */
   FSE_repeat_check, /**< Can use the previous table but it must be checked */
   FSE_repeat_valid  /**< Can use the previous table and it is assumed to be valid */
 } FSE_repeat;

/* *****************************************
*  FSE symbol compression API
*******************************************/
/*!
   This API consists of small unitary functions, which highly benefit from being inlined.
   Hence their body are included in next section.
*/
typedef struct {
    ptrdiff_t   value;
    const void* stateTable;
    const void* symbolTT;
    unsigned    stateLog;
} FSE_CState_t;

static void FSE_initCState(FSE_CState_t* CStatePtr, const FSE_CTable* ct);

static void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* CStatePtr, unsigned symbol);

static void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* CStatePtr);

/**<
These functions are inner components of FSE_compress_usingCTable().
They allow the creation of custom streams, mixing multiple tables and bit sources.

A key property to keep in mind is that encoding and decoding are done **in reverse direction**.
So the first symbol you will encode is the last you will decode, like a LIFO stack.

You will need a few variables to track your CStream. They are :

FSE_CTable    ct;         // Provided by FSE_buildCTable()
BIT_CStream_t bitStream;  // bitStream tracking structure
FSE_CState_t  state;      // State tracking structure (can have several)


The first thing to do is to init bitStream and state.
    size_t errorCode = BIT_initCStream(&bitStream, dstBuffer, maxDstSize);
    FSE_initCState(&state, ct);

Note that BIT_initCStream() can produce an error code, so its result should be tested, using FSE_isError();
You can then encode your input data, byte after byte.
FSE_encodeSymbol() outputs a maximum of 'tableLog' bits at a time.
Remember decoding will be done in reverse direction.
    FSE_encodeByte(&bitStream, &state, symbol);

At any time, you can also add any bit sequence.
Note : maximum allowed nbBits is 25, for compatibility with 32-bits decoders
    BIT_addBits(&bitStream, bitField, nbBits);

The above methods don't commit data to memory, they just store it into local register, for speed.
Local register size is 64-bits on 64-bits systems, 32-bits on 32-bits systems (size_t).
Writing data to memory is a manual operation, performed by the flushBits function.
    BIT_flushBits(&bitStream);

Your last FSE encoding operation shall be to flush your last state value(s).
    FSE_flushState(&bitStream, &state);

Finally, you must close the bitStream.
The function returns the size of CStream in bytes.
If data couldn't fit into dstBuffer, it will return a 0 ( == not compressible)
If there is an error, it returns an errorCode (which can be tested using FSE_isError()).
    size_t size = BIT_closeCStream(&bitStream);
*/


/* *****************************************
*  FSE symbol decompression API
*******************************************/
typedef struct {
    size_t      state;
    const void* table;   /* precise table may vary, depending on U16 */
} FSE_DState_t;


static void     FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt);

static unsigned char FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);

static unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr);

/**<
Let's now decompose FSE_decompress_usingDTable() into its unitary components.
You will decode FSE-encoded symbols from the bitStream,
and also any other bitFields you put in, **in reverse order**.

You will need a few variables to track your bitStream. They are :

BIT_DStream_t DStream;    // Stream context
FSE_DState_t  DState;     // State context. Multiple ones are possible
FSE_DTable*   DTablePtr;  // Decoding table, provided by FSE_buildDTable()

The first thing to do is to init the bitStream.
    errorCode = BIT_initDStream(&DStream, srcBuffer, srcSize);

You should then retrieve your initial state(s)
(in reverse flushing order if you have several ones) :
    errorCode = FSE_initDState(&DState, &DStream, DTablePtr);

You can then decode your data, symbol after symbol.
For information the maximum number of bits read by FSE_decodeSymbol() is 'tableLog'.
Keep in mind that symbols are decoded in reverse order, like a LIFO stack (last in, first out).
    unsigned char symbol = FSE_decodeSymbol(&DState, &DStream);

You can retrieve any bitfield you eventually stored into the bitStream (in reverse order)
Note : maximum allowed nbBits is 25, for 32-bits compatibility
    size_t bitField = BIT_readBits(&DStream, nbBits);

All above operations only read from local register (which size depends on size_t).
Refueling the register from memory is manually performed by the reload method.
    endSignal = FSE_reloadDStream(&DStream);

BIT_reloadDStream() result tells if there is still some more data to read from DStream.
BIT_DStream_unfinished : there is still some data left into the DStream.
BIT_DStream_endOfBuffer : Dstream reached end of buffer. Its container may no longer be completely filled.
BIT_DStream_completed : Dstream reached its exact end, corresponding in general to decompression completed.
BIT_DStream_tooFar : Dstream went too far. Decompression result is corrupted.

When reaching end of buffer (BIT_DStream_endOfBuffer), progress slowly, notably if you decode multiple symbols per loop,
to properly detect the exact end of stream.
After each decoded symbol, check if DStream is fully consumed using this simple test :
    BIT_reloadDStream(&DStream) >= BIT_DStream_completed

When it's done, verify decompression is fully completed, by checking both DStream and the relevant states.
Checking if DStream has reached its end is performed by :
    BIT_endOfDStream(&DStream);
Check also the states. There might be some symbols left there, if some high probability ones (>50%) are possible.
    FSE_endOfDState(&DState);
*/


/* *****************************************
*  FSE unsafe API
*******************************************/
static unsigned char FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD);
/* faster, but works only if nbBits is always >= 1 (otherwise, result will be corrupted) */


/* *****************************************
*  Implementation of inlined functions
*******************************************/
typedef struct {
    int deltaFindState;
    U32 deltaNbBits;
} FSE_symbolCompressionTransform; /* total 8 bytes */

MEM_STATIC void FSE_initCState(FSE_CState_t* statePtr, const FSE_CTable* ct)
{
    const void* ptr = ct;
    const U16* u16ptr = (const U16*) ptr;
    const U32 tableLog = MEM_read16(ptr);
    statePtr->value = (ptrdiff_t)1<<tableLog;
    statePtr->stateTable = u16ptr+2;
    statePtr->symbolTT = ct + 1 + (tableLog ? (1<<(tableLog-1)) : 1);
    statePtr->stateLog = tableLog;
}


/*! FSE_initCState2() :
*   Same as FSE_initCState(), but the first symbol to include (which will be the last to be read)
*   uses the smallest state value possible, saving the cost of this symbol */
MEM_STATIC void FSE_initCState2(FSE_CState_t* statePtr, const FSE_CTable* ct, U32 symbol)
{
    FSE_initCState(statePtr, ct);
    {   const FSE_symbolCompressionTransform symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
        const U16* stateTable = (const U16*)(statePtr->stateTable);
        U32 nbBitsOut  = (U32)((symbolTT.deltaNbBits + (1<<15)) >> 16);
        statePtr->value = (nbBitsOut << 16) - symbolTT.deltaNbBits;
        statePtr->value = stateTable[(statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
    }
}

MEM_STATIC void FSE_encodeSymbol(BIT_CStream_t* bitC, FSE_CState_t* statePtr, unsigned symbol)
{
    FSE_symbolCompressionTransform const symbolTT = ((const FSE_symbolCompressionTransform*)(statePtr->symbolTT))[symbol];
    const U16* const stateTable = (const U16*)(statePtr->stateTable);
    U32 const nbBitsOut  = (U32)((statePtr->value + symbolTT.deltaNbBits) >> 16);
    BIT_addBits(bitC,  (size_t)statePtr->value, nbBitsOut);
    statePtr->value = stateTable[ (statePtr->value >> nbBitsOut) + symbolTT.deltaFindState];
}

MEM_STATIC void FSE_flushCState(BIT_CStream_t* bitC, const FSE_CState_t* statePtr)
{
    BIT_addBits(bitC, (size_t)statePtr->value, statePtr->stateLog);
    BIT_flushBits(bitC);
}


/* FSE_getMaxNbBits() :
 * Approximate maximum cost of a symbol, in bits.
 * Fractional get rounded up (i.e. a symbol with a normalized frequency of 3 gives the same result as a frequency of 2)
 * note 1 : assume symbolValue is valid (<= maxSymbolValue)
 * note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
MEM_STATIC U32 FSE_getMaxNbBits(const void* symbolTTPtr, U32 symbolValue)
{
    const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
    return (symbolTT[symbolValue].deltaNbBits + ((1<<16)-1)) >> 16;
}

/* FSE_bitCost() :
 * Approximate symbol cost, as fractional value, using fixed-point format (accuracyLog fractional bits)
 * note 1 : assume symbolValue is valid (<= maxSymbolValue)
 * note 2 : if freq[symbolValue]==0, @return a fake cost of tableLog+1 bits */
MEM_STATIC U32 FSE_bitCost(const void* symbolTTPtr, U32 tableLog, U32 symbolValue, U32 accuracyLog)
{
    const FSE_symbolCompressionTransform* symbolTT = (const FSE_symbolCompressionTransform*) symbolTTPtr;
    U32 const minNbBits = symbolTT[symbolValue].deltaNbBits >> 16;
    U32 const threshold = (minNbBits+1) << 16;
    assert(tableLog < 16);
    assert(accuracyLog < 31-tableLog);  /* ensure enough room for renormalization double shift */
    {   U32 const tableSize = 1 << tableLog;
        U32 const deltaFromThreshold = threshold - (symbolTT[symbolValue].deltaNbBits + tableSize);
        U32 const normalizedDeltaFromThreshold = (deltaFromThreshold << accuracyLog) >> tableLog;   /* linear interpolation (very approximate) */
        U32 const bitMultiplier = 1 << accuracyLog;
        assert(symbolTT[symbolValue].deltaNbBits + tableSize <= threshold);
        assert(normalizedDeltaFromThreshold <= bitMultiplier);
        return (minNbBits+1)*bitMultiplier - normalizedDeltaFromThreshold;
    }
}


/* ======    Decompression    ====== */

typedef struct {
    U16 tableLog;
    U16 fastMode;
} FSE_DTableHeader;   /* sizeof U32 */

typedef struct
{
    unsigned short newState;
    unsigned char  symbol;
    unsigned char  nbBits;
} FSE_decode_t;   /* size == U32 */

MEM_STATIC void FSE_initDState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD, const FSE_DTable* dt)
{
    const void* ptr = dt;
    const FSE_DTableHeader* const DTableH = (const FSE_DTableHeader*)ptr;
    DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
    BIT_reloadDStream(bitD);
    DStatePtr->table = dt + 1;
}

MEM_STATIC BYTE FSE_peekSymbol(const FSE_DState_t* DStatePtr)
{
    FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
    return DInfo.symbol;
}

MEM_STATIC void FSE_updateState(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
{
    FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
    U32 const nbBits = DInfo.nbBits;
    size_t const lowBits = BIT_readBits(bitD, nbBits);
    DStatePtr->state = DInfo.newState + lowBits;
}

MEM_STATIC BYTE FSE_decodeSymbol(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
{
    FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
    U32 const nbBits = DInfo.nbBits;
    BYTE const symbol = DInfo.symbol;
    size_t const lowBits = BIT_readBits(bitD, nbBits);

    DStatePtr->state = DInfo.newState + lowBits;
    return symbol;
}

/*! FSE_decodeSymbolFast() :
    unsafe, only works if no symbol has a probability > 50% */
MEM_STATIC BYTE FSE_decodeSymbolFast(FSE_DState_t* DStatePtr, BIT_DStream_t* bitD)
{
    FSE_decode_t const DInfo = ((const FSE_decode_t*)(DStatePtr->table))[DStatePtr->state];
    U32 const nbBits = DInfo.nbBits;
    BYTE const symbol = DInfo.symbol;
    size_t const lowBits = BIT_readBitsFast(bitD, nbBits);

    DStatePtr->state = DInfo.newState + lowBits;
    return symbol;
}

MEM_STATIC unsigned FSE_endOfDState(const FSE_DState_t* DStatePtr)
{
    return DStatePtr->state == 0;
}



#ifndef FSE_COMMONDEFS_ONLY

/* **************************************************************
*  Tuning parameters
****************************************************************/
/*!MEMORY_USAGE :
*  Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
*  Increasing memory usage improves compression ratio
*  Reduced memory usage can improve speed, due to cache effect
*  Recommended max value is 14, for 16KB, which nicely fits into Intel x86 L1 cache */
#ifndef FSE_MAX_MEMORY_USAGE
#  define FSE_MAX_MEMORY_USAGE 14
#endif
#ifndef FSE_DEFAULT_MEMORY_USAGE
#  define FSE_DEFAULT_MEMORY_USAGE 13
#endif
#if (FSE_DEFAULT_MEMORY_USAGE > FSE_MAX_MEMORY_USAGE)
#  error "FSE_DEFAULT_MEMORY_USAGE must be <= FSE_MAX_MEMORY_USAGE"
#endif

/*!FSE_MAX_SYMBOL_VALUE :
*  Maximum symbol value authorized.
*  Required for proper stack allocation */
#ifndef FSE_MAX_SYMBOL_VALUE
#  define FSE_MAX_SYMBOL_VALUE 255
#endif

/* **************************************************************
*  template functions type & suffix
****************************************************************/
#define FSE_FUNCTION_TYPE BYTE
#define FSE_FUNCTION_EXTENSION
#define FSE_DECODE_TYPE FSE_decode_t


#endif   /* !FSE_COMMONDEFS_ONLY */


/* ***************************************************************
*  Constants
*****************************************************************/
#define FSE_MAX_TABLELOG  (FSE_MAX_MEMORY_USAGE-2)
#define FSE_MAX_TABLESIZE (1U<<FSE_MAX_TABLELOG)
#define FSE_MAXTABLESIZE_MASK (FSE_MAX_TABLESIZE-1)
#define FSE_DEFAULT_TABLELOG (FSE_DEFAULT_MEMORY_USAGE-2)
#define FSE_MIN_TABLELOG 5

#define FSE_TABLELOG_ABSOLUTE_MAX 15
#if FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX
#  error "FSE_MAX_TABLELOG > FSE_TABLELOG_ABSOLUTE_MAX is not supported"
#endif

#define FSE_TABLESTEP(tableSize) (((tableSize)>>1) + ((tableSize)>>3) + 3)


#endif /* FSE_STATIC_LINKING_ONLY */


#if defined (__cplusplus)
}
#endif
/**** ended inlining fse.h ****/
/**** start inlining huf.h ****/
/* ******************************************************************
 * huff0 huffman codec,
 * part of Finite State Entropy library
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * You can contact the author at :
 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */

#if defined (__cplusplus)
extern "C" {
#endif

#ifndef HUF_H_298734234
#define HUF_H_298734234

/* *** Dependencies *** */
/**** skipping file: zstd_deps.h ****/
/**** skipping file: mem.h ****/
#define FSE_STATIC_LINKING_ONLY
/**** skipping file: fse.h ****/


/* ***   Tool functions *** */
#define HUF_BLOCKSIZE_MAX (128 * 1024)   /**< maximum input size for a single block compressed with HUF_compress */
size_t HUF_compressBound(size_t size);   /**< maximum compressed size (worst case) */

/* Error Management */
unsigned    HUF_isError(size_t code);       /**< tells if a return value is an error code */
const char* HUF_getErrorName(size_t code);  /**< provides error code string (useful for debugging) */


#define HUF_WORKSPACE_SIZE ((8 << 10) + 512 /* sorting scratch space */)
#define HUF_WORKSPACE_SIZE_U64 (HUF_WORKSPACE_SIZE / sizeof(U64))

/* *** Constants *** */
#define HUF_TABLELOG_MAX      12      /* max runtime value of tableLog (due to static allocation); can be modified up to HUF_TABLELOG_ABSOLUTEMAX */
#define HUF_TABLELOG_DEFAULT  11      /* default tableLog value when none specified */
#define HUF_SYMBOLVALUE_MAX  255

#define HUF_TABLELOG_ABSOLUTEMAX  12  /* absolute limit of HUF_MAX_TABLELOG. Beyond that value, code does not work */
#if (HUF_TABLELOG_MAX > HUF_TABLELOG_ABSOLUTEMAX)
#  error "HUF_TABLELOG_MAX is too large !"
#endif


/* ****************************************
*  Static allocation
******************************************/
/* HUF buffer bounds */
#define HUF_CTABLEBOUND 129
#define HUF_BLOCKBOUND(size) (size + (size>>8) + 8)   /* only true when incompressible is pre-filtered with fast heuristic */
#define HUF_COMPRESSBOUND(size) (HUF_CTABLEBOUND + HUF_BLOCKBOUND(size))   /* Macro version, useful for static allocation */

/* static allocation of HUF's Compression Table */
/* this is a private definition, just exposed for allocation and strict aliasing purpose. never EVER access its members directly */
typedef size_t HUF_CElt;   /* consider it an incomplete type */
#define HUF_CTABLE_SIZE_ST(maxSymbolValue)   ((maxSymbolValue)+2)   /* Use tables of size_t, for proper alignment */
#define HUF_CTABLE_SIZE(maxSymbolValue)       (HUF_CTABLE_SIZE_ST(maxSymbolValue) * sizeof(size_t))
#define HUF_CREATE_STATIC_CTABLE(name, maxSymbolValue) \
    HUF_CElt name[HUF_CTABLE_SIZE_ST(maxSymbolValue)] /* no final ; */

/* static allocation of HUF's DTable */
typedef U32 HUF_DTable;
#define HUF_DTABLE_SIZE(maxTableLog)   (1 + (1<<(maxTableLog)))
#define HUF_CREATE_STATIC_DTABLEX1(DTable, maxTableLog) \
        HUF_DTable DTable[HUF_DTABLE_SIZE((maxTableLog)-1)] = { ((U32)((maxTableLog)-1) * 0x01000001) }
#define HUF_CREATE_STATIC_DTABLEX2(DTable, maxTableLog) \
        HUF_DTable DTable[HUF_DTABLE_SIZE(maxTableLog)] = { ((U32)(maxTableLog) * 0x01000001) }


/* ****************************************
*  Advanced decompression functions
******************************************/

/**
 * Huffman flags bitset.
 * For all flags, 0 is the default value.
 */
typedef enum {
    /**
     * If compiled with DYNAMIC_BMI2: Set flag only if the CPU supports BMI2 at runtime.
     * Otherwise: Ignored.
     */
    HUF_flags_bmi2 = (1 << 0),
    /**
     * If set: Test possible table depths to find the one that produces the smallest header + encoded size.
     * If unset: Use heuristic to find the table depth.
     */
    HUF_flags_optimalDepth = (1 << 1),
    /**
     * If set: If the previous table can encode the input, always reuse the previous table.
     * If unset: If the previous table can encode the input, reuse the previous table if it results in a smaller output.
     */
    HUF_flags_preferRepeat = (1 << 2),
    /**
     * If set: Sample the input and check if the sample is uncompressible, if it is then don't attempt to compress.
     * If unset: Always histogram the entire input.
     */
    HUF_flags_suspectUncompressible = (1 << 3),
    /**
     * If set: Don't use assembly implementations
     * If unset: Allow using assembly implementations
     */
    HUF_flags_disableAsm = (1 << 4),
    /**
     * If set: Don't use the fast decoding loop, always use the fallback decoding loop.
     * If unset: Use the fast decoding loop when possible.
     */
    HUF_flags_disableFast = (1 << 5)
} HUF_flags_e;


/* ****************************************
 *  HUF detailed API
 * ****************************************/
#define HUF_OPTIMAL_DEPTH_THRESHOLD ZSTD_btultra

/*! HUF_compress() does the following:
 *  1. count symbol occurrence from source[] into table count[] using FSE_count() (exposed within "fse.h")
 *  2. (optional) refine tableLog using HUF_optimalTableLog()
 *  3. build Huffman table from count using HUF_buildCTable()
 *  4. save Huffman table to memory buffer using HUF_writeCTable()
 *  5. encode the data stream using HUF_compress4X_usingCTable()
 *
 *  The following API allows targeting specific sub-functions for advanced tasks.
 *  For example, it's possible to compress several blocks using the same 'CTable',
 *  or to save and regenerate 'CTable' using external methods.
 */
unsigned HUF_minTableLog(unsigned symbolCardinality);
unsigned HUF_cardinality(const unsigned* count, unsigned maxSymbolValue);
unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, void* workSpace,
 size_t wkspSize, HUF_CElt* table, const unsigned* count, int flags); /* table is used as scratch space for building and testing tables, not a return value */
size_t HUF_writeCTable_wksp(void* dst, size_t maxDstSize, const HUF_CElt* CTable, unsigned maxSymbolValue, unsigned huffLog, void* workspace, size_t workspaceSize);
size_t HUF_compress4X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable, int flags);
size_t HUF_estimateCompressedSize(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue);
int HUF_validateCTable(const HUF_CElt* CTable, const unsigned* count, unsigned maxSymbolValue);

typedef enum {
   HUF_repeat_none,  /**< Cannot use the previous table */
   HUF_repeat_check, /**< Can use the previous table but it must be checked. Note : The previous table must have been constructed by HUF_compress{1, 4}X_repeat */
   HUF_repeat_valid  /**< Can use the previous table and it is assumed to be valid */
 } HUF_repeat;

/** HUF_compress4X_repeat() :
 *  Same as HUF_compress4X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
 *  If it uses hufTable it does not modify hufTable or repeat.
 *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
 *  If preferRepeat then the old table will always be used if valid.
 *  If suspectUncompressible then some sampling checks will be run to potentially skip huffman coding */
size_t HUF_compress4X_repeat(void* dst, size_t dstSize,
                       const void* src, size_t srcSize,
                       unsigned maxSymbolValue, unsigned tableLog,
                       void* workSpace, size_t wkspSize,    /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
                       HUF_CElt* hufTable, HUF_repeat* repeat, int flags);

/** HUF_buildCTable_wksp() :
 *  Same as HUF_buildCTable(), but using externally allocated scratch buffer.
 * `workSpace` must be aligned on 4-bytes boundaries, and its size must be >= HUF_CTABLE_WORKSPACE_SIZE.
 */
#define HUF_CTABLE_WORKSPACE_SIZE_U32 ((4 * (HUF_SYMBOLVALUE_MAX + 1)) + 192)
#define HUF_CTABLE_WORKSPACE_SIZE (HUF_CTABLE_WORKSPACE_SIZE_U32 * sizeof(unsigned))
size_t HUF_buildCTable_wksp (HUF_CElt* tree,
                       const unsigned* count, U32 maxSymbolValue, U32 maxNbBits,
                             void* workSpace, size_t wkspSize);

/*! HUF_readStats() :
 *  Read compact Huffman tree, saved by HUF_writeCTable().
 * `huffWeight` is destination buffer.
 * @return : size read from `src` , or an error Code .
 *  Note : Needed by HUF_readCTable() and HUF_readDTableXn() . */
size_t HUF_readStats(BYTE* huffWeight, size_t hwSize,
                     U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr,
                     const void* src, size_t srcSize);

/*! HUF_readStats_wksp() :
 * Same as HUF_readStats() but takes an external workspace which must be
 * 4-byte aligned and its size must be >= HUF_READ_STATS_WORKSPACE_SIZE.
 * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0.
 */
#define HUF_READ_STATS_WORKSPACE_SIZE_U32 FSE_DECOMPRESS_WKSP_SIZE_U32(6, HUF_TABLELOG_MAX-1)
#define HUF_READ_STATS_WORKSPACE_SIZE (HUF_READ_STATS_WORKSPACE_SIZE_U32 * sizeof(unsigned))
size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize,
                          U32* rankStats, U32* nbSymbolsPtr, U32* tableLogPtr,
                          const void* src, size_t srcSize,
                          void* workspace, size_t wkspSize,
                          int flags);

/** HUF_readCTable() :
 *  Loading a CTable saved with HUF_writeCTable() */
size_t HUF_readCTable (HUF_CElt* CTable, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize, unsigned *hasZeroWeights);

/** HUF_getNbBitsFromCTable() :
 *  Read nbBits from CTable symbolTable, for symbol `symbolValue` presumed <= HUF_SYMBOLVALUE_MAX
 *  Note 1 : If symbolValue > HUF_readCTableHeader(symbolTable).maxSymbolValue, returns 0
 *  Note 2 : is not inlined, as HUF_CElt definition is private
 */
U32 HUF_getNbBitsFromCTable(const HUF_CElt* symbolTable, U32 symbolValue);

typedef struct {
    BYTE tableLog;
    BYTE maxSymbolValue;
    BYTE unused[sizeof(size_t) - 2];
} HUF_CTableHeader;

/** HUF_readCTableHeader() :
 *  @returns The header from the CTable specifying the tableLog and the maxSymbolValue.
 */
HUF_CTableHeader HUF_readCTableHeader(HUF_CElt const* ctable);

/*
 * HUF_decompress() does the following:
 * 1. select the decompression algorithm (X1, X2) based on pre-computed heuristics
 * 2. build Huffman table from save, using HUF_readDTableX?()
 * 3. decode 1 or 4 segments in parallel using HUF_decompress?X?_usingDTable()
 */

/** HUF_selectDecoder() :
 *  Tells which decoder is likely to decode faster,
 *  based on a set of pre-computed metrics.
 * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
 *  Assumption : 0 < dstSize <= 128 KB */
U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize);

/**
 *  The minimum workspace size for the `workSpace` used in
 *  HUF_readDTableX1_wksp() and HUF_readDTableX2_wksp().
 *
 *  The space used depends on HUF_TABLELOG_MAX, ranging from ~1500 bytes when
 *  HUF_TABLE_LOG_MAX=12 to ~1850 bytes when HUF_TABLE_LOG_MAX=15.
 *  Buffer overflow errors may potentially occur if code modifications result in
 *  a required workspace size greater than that specified in the following
 *  macro.
 */
#define HUF_DECOMPRESS_WORKSPACE_SIZE ((2 << 10) + (1 << 9))
#define HUF_DECOMPRESS_WORKSPACE_SIZE_U32 (HUF_DECOMPRESS_WORKSPACE_SIZE / sizeof(U32))


/* ====================== */
/* single stream variants */
/* ====================== */

size_t HUF_compress1X_usingCTable(void* dst, size_t dstSize, const void* src, size_t srcSize, const HUF_CElt* CTable, int flags);
/** HUF_compress1X_repeat() :
 *  Same as HUF_compress1X_wksp(), but considers using hufTable if *repeat != HUF_repeat_none.
 *  If it uses hufTable it does not modify hufTable or repeat.
 *  If it doesn't, it sets *repeat = HUF_repeat_none, and it sets hufTable to the table used.
 *  If preferRepeat then the old table will always be used if valid.
 *  If suspectUncompressible then some sampling checks will be run to potentially skip huffman coding */
size_t HUF_compress1X_repeat(void* dst, size_t dstSize,
                       const void* src, size_t srcSize,
                       unsigned maxSymbolValue, unsigned tableLog,
                       void* workSpace, size_t wkspSize,   /**< `workSpace` must be aligned on 4-bytes boundaries, `wkspSize` must be >= HUF_WORKSPACE_SIZE */
                       HUF_CElt* hufTable, HUF_repeat* repeat, int flags);

size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags);
#ifndef HUF_FORCE_DECOMPRESS_X1
size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags);   /**< double-symbols decoder */
#endif

/* BMI2 variants.
 * If the CPU has BMI2 support, pass bmi2=1, otherwise pass bmi2=0.
 */
size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags);
#ifndef HUF_FORCE_DECOMPRESS_X2
size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags);
#endif
size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags);
size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags);
#ifndef HUF_FORCE_DECOMPRESS_X2
size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags);
#endif
#ifndef HUF_FORCE_DECOMPRESS_X1
size_t HUF_readDTableX2_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags);
#endif

#endif   /* HUF_H_298734234 */

#if defined (__cplusplus)
}
#endif
/**** ended inlining huf.h ****/
/**** skipping file: bits.h ****/


/*===   Version   ===*/
unsigned FSE_versionNumber(void) { return FSE_VERSION_NUMBER; }


/*===   Error Management   ===*/
unsigned FSE_isError(size_t code) { return ERR_isError(code); }
const char* FSE_getErrorName(size_t code) { return ERR_getErrorName(code); }

unsigned HUF_isError(size_t code) { return ERR_isError(code); }
const char* HUF_getErrorName(size_t code) { return ERR_getErrorName(code); }


/*-**************************************************************
*  FSE NCount encoding-decoding
****************************************************************/
FORCE_INLINE_TEMPLATE
size_t FSE_readNCount_body(short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
                           const void* headerBuffer, size_t hbSize)
{
    const BYTE* const istart = (const BYTE*) headerBuffer;
    const BYTE* const iend = istart + hbSize;
    const BYTE* ip = istart;
    int nbBits;
    int remaining;
    int threshold;
    U32 bitStream;
    int bitCount;
    unsigned charnum = 0;
    unsigned const maxSV1 = *maxSVPtr + 1;
    int previous0 = 0;

    if (hbSize < 8) {
        /* This function only works when hbSize >= 8 */
        char buffer[8] = {0};
        ZSTD_memcpy(buffer, headerBuffer, hbSize);
        {   size_t const countSize = FSE_readNCount(normalizedCounter, maxSVPtr, tableLogPtr,
                                                    buffer, sizeof(buffer));
            if (FSE_isError(countSize)) return countSize;
            if (countSize > hbSize) return ERROR(corruption_detected);
            return countSize;
    }   }
    assert(hbSize >= 8);

    /* init */
    ZSTD_memset(normalizedCounter, 0, (*maxSVPtr+1) * sizeof(normalizedCounter[0]));   /* all symbols not present in NCount have a frequency of 0 */
    bitStream = MEM_readLE32(ip);
    nbBits = (bitStream & 0xF) + FSE_MIN_TABLELOG;   /* extract tableLog */
    if (nbBits > FSE_TABLELOG_ABSOLUTE_MAX) return ERROR(tableLog_tooLarge);
    bitStream >>= 4;
    bitCount = 4;
    *tableLogPtr = nbBits;
    remaining = (1<<nbBits)+1;
    threshold = 1<<nbBits;
    nbBits++;

    for (;;) {
        if (previous0) {
            /* Count the number of repeats. Each time the
             * 2-bit repeat code is 0b11 there is another
             * repeat.
             * Avoid UB by setting the high bit to 1.
             */
            int repeats = ZSTD_countTrailingZeros32(~bitStream | 0x80000000) >> 1;
            while (repeats >= 12) {
                charnum += 3 * 12;
                if (LIKELY(ip <= iend-7)) {
                    ip += 3;
                } else {
                    bitCount -= (int)(8 * (iend - 7 - ip));
                    bitCount &= 31;
                    ip = iend - 4;
                }
                bitStream = MEM_readLE32(ip) >> bitCount;
                repeats = ZSTD_countTrailingZeros32(~bitStream | 0x80000000) >> 1;
            }
            charnum += 3 * repeats;
            bitStream >>= 2 * repeats;
            bitCount += 2 * repeats;

            /* Add the final repeat which isn't 0b11. */
            assert((bitStream & 3) < 3);
            charnum += bitStream & 3;
            bitCount += 2;

            /* This is an error, but break and return an error
             * at the end, because returning out of a loop makes
             * it harder for the compiler to optimize.
             */
            if (charnum >= maxSV1) break;

            /* We don't need to set the normalized count to 0
             * because we already memset the whole buffer to 0.
             */

            if (LIKELY(ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
                assert((bitCount >> 3) <= 3); /* For first condition to work */
                ip += bitCount>>3;
                bitCount &= 7;
            } else {
                bitCount -= (int)(8 * (iend - 4 - ip));
                bitCount &= 31;
                ip = iend - 4;
            }
            bitStream = MEM_readLE32(ip) >> bitCount;
        }
        {
            int const max = (2*threshold-1) - remaining;
            int count;

            if ((bitStream & (threshold-1)) < (U32)max) {
                count = bitStream & (threshold-1);
                bitCount += nbBits-1;
            } else {
                count = bitStream & (2*threshold-1);
                if (count >= threshold) count -= max;
                bitCount += nbBits;
            }

            count--;   /* extra accuracy */
            /* When it matters (small blocks), this is a
             * predictable branch, because we don't use -1.
             */
            if (count >= 0) {
                remaining -= count;
            } else {
                assert(count == -1);
                remaining += count;
            }
            normalizedCounter[charnum++] = (short)count;
            previous0 = !count;

            assert(threshold > 1);
            if (remaining < threshold) {
                /* This branch can be folded into the
                 * threshold update condition because we
                 * know that threshold > 1.
                 */
                if (remaining <= 1) break;
                nbBits = ZSTD_highbit32(remaining) + 1;
                threshold = 1 << (nbBits - 1);
            }
            if (charnum >= maxSV1) break;

            if (LIKELY(ip <= iend-7) || (ip + (bitCount>>3) <= iend-4)) {
                ip += bitCount>>3;
                bitCount &= 7;
            } else {
                bitCount -= (int)(8 * (iend - 4 - ip));
                bitCount &= 31;
                ip = iend - 4;
            }
            bitStream = MEM_readLE32(ip) >> bitCount;
    }   }
    if (remaining != 1) return ERROR(corruption_detected);
    /* Only possible when there are too many zeros. */
    if (charnum > maxSV1) return ERROR(maxSymbolValue_tooSmall);
    if (bitCount > 32) return ERROR(corruption_detected);
    *maxSVPtr = charnum-1;

    ip += (bitCount+7)>>3;
    return ip-istart;
}

/* Avoids the FORCE_INLINE of the _body() function. */
static size_t FSE_readNCount_body_default(
        short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
        const void* headerBuffer, size_t hbSize)
{
    return FSE_readNCount_body(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
}

#if DYNAMIC_BMI2
BMI2_TARGET_ATTRIBUTE static size_t FSE_readNCount_body_bmi2(
        short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
        const void* headerBuffer, size_t hbSize)
{
    return FSE_readNCount_body(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
}
#endif

size_t FSE_readNCount_bmi2(
        short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
        const void* headerBuffer, size_t hbSize, int bmi2)
{
#if DYNAMIC_BMI2
    if (bmi2) {
        return FSE_readNCount_body_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
    }
#endif
    (void)bmi2;
    return FSE_readNCount_body_default(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize);
}

size_t FSE_readNCount(
        short* normalizedCounter, unsigned* maxSVPtr, unsigned* tableLogPtr,
        const void* headerBuffer, size_t hbSize)
{
    return FSE_readNCount_bmi2(normalizedCounter, maxSVPtr, tableLogPtr, headerBuffer, hbSize, /* bmi2 */ 0);
}


/*! HUF_readStats() :
    Read compact Huffman tree, saved by HUF_writeCTable().
    `huffWeight` is destination buffer.
    `rankStats` is assumed to be a table of at least HUF_TABLELOG_MAX U32.
    @return : size read from `src` , or an error Code .
    Note : Needed by HUF_readCTable() and HUF_readDTableX?() .
*/
size_t HUF_readStats(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                     U32* nbSymbolsPtr, U32* tableLogPtr,
                     const void* src, size_t srcSize)
{
    U32 wksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
    return HUF_readStats_wksp(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, wksp, sizeof(wksp), /* flags */ 0);
}

FORCE_INLINE_TEMPLATE size_t
HUF_readStats_body(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                   U32* nbSymbolsPtr, U32* tableLogPtr,
                   const void* src, size_t srcSize,
                   void* workSpace, size_t wkspSize,
                   int bmi2)
{
    U32 weightTotal;
    const BYTE* ip = (const BYTE*) src;
    size_t iSize;
    size_t oSize;

    if (!srcSize) return ERROR(srcSize_wrong);
    iSize = ip[0];
    /* ZSTD_memset(huffWeight, 0, hwSize);   *//* is not necessary, even though some analyzer complain ... */

    if (iSize >= 128) {  /* special header */
        oSize = iSize - 127;
        iSize = ((oSize+1)/2);
        if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
        if (oSize >= hwSize) return ERROR(corruption_detected);
        ip += 1;
        {   U32 n;
            for (n=0; n<oSize; n+=2) {
                huffWeight[n]   = ip[n/2] >> 4;
                huffWeight[n+1] = ip[n/2] & 15;
    }   }   }
    else  {   /* header compressed with FSE (normal case) */
        if (iSize+1 > srcSize) return ERROR(srcSize_wrong);
        /* max (hwSize-1) values decoded, as last one is implied */
        oSize = FSE_decompress_wksp_bmi2(huffWeight, hwSize-1, ip+1, iSize, 6, workSpace, wkspSize, bmi2);
        if (FSE_isError(oSize)) return oSize;
    }

    /* collect weight stats */
    ZSTD_memset(rankStats, 0, (HUF_TABLELOG_MAX + 1) * sizeof(U32));
    weightTotal = 0;
    {   U32 n; for (n=0; n<oSize; n++) {
            if (huffWeight[n] > HUF_TABLELOG_MAX) return ERROR(corruption_detected);
            rankStats[huffWeight[n]]++;
            weightTotal += (1 << huffWeight[n]) >> 1;
    }   }
    if (weightTotal == 0) return ERROR(corruption_detected);

    /* get last non-null symbol weight (implied, total must be 2^n) */
    {   U32 const tableLog = ZSTD_highbit32(weightTotal) + 1;
        if (tableLog > HUF_TABLELOG_MAX) return ERROR(corruption_detected);
        *tableLogPtr = tableLog;
        /* determine last weight */
        {   U32 const total = 1 << tableLog;
            U32 const rest = total - weightTotal;
            U32 const verif = 1 << ZSTD_highbit32(rest);
            U32 const lastWeight = ZSTD_highbit32(rest) + 1;
            if (verif != rest) return ERROR(corruption_detected);    /* last value must be a clean power of 2 */
            huffWeight[oSize] = (BYTE)lastWeight;
            rankStats[lastWeight]++;
    }   }

    /* check tree construction validity */
    if ((rankStats[1] < 2) || (rankStats[1] & 1)) return ERROR(corruption_detected);   /* by construction : at least 2 elts of rank 1, must be even */

    /* results */
    *nbSymbolsPtr = (U32)(oSize+1);
    return iSize+1;
}

/* Avoids the FORCE_INLINE of the _body() function. */
static size_t HUF_readStats_body_default(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                     U32* nbSymbolsPtr, U32* tableLogPtr,
                     const void* src, size_t srcSize,
                     void* workSpace, size_t wkspSize)
{
    return HUF_readStats_body(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize, 0);
}

#if DYNAMIC_BMI2
static BMI2_TARGET_ATTRIBUTE size_t HUF_readStats_body_bmi2(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                     U32* nbSymbolsPtr, U32* tableLogPtr,
                     const void* src, size_t srcSize,
                     void* workSpace, size_t wkspSize)
{
    return HUF_readStats_body(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize, 1);
}
#endif

size_t HUF_readStats_wksp(BYTE* huffWeight, size_t hwSize, U32* rankStats,
                     U32* nbSymbolsPtr, U32* tableLogPtr,
                     const void* src, size_t srcSize,
                     void* workSpace, size_t wkspSize,
                     int flags)
{
#if DYNAMIC_BMI2
    if (flags & HUF_flags_bmi2) {
        return HUF_readStats_body_bmi2(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
    }
#endif
    (void)flags;
    return HUF_readStats_body_default(huffWeight, hwSize, rankStats, nbSymbolsPtr, tableLogPtr, src, srcSize, workSpace, wkspSize);
}
/**** ended inlining common/entropy_common.c ****/
/**** start inlining common/error_private.c ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* The purpose of this file is to have a single list of error strings embedded in binary */

/**** skipping file: error_private.h ****/

const char* ERR_getErrorString(ERR_enum code)
{
#ifdef ZSTD_STRIP_ERROR_STRINGS
    (void)code;
    return "Error strings stripped";
#else
    static const char* const notErrorCode = "Unspecified error code";
    switch( code )
    {
    case PREFIX(no_error): return "No error detected";
    case PREFIX(GENERIC):  return "Error (generic)";
    case PREFIX(prefix_unknown): return "Unknown frame descriptor";
    case PREFIX(version_unsupported): return "Version not supported";
    case PREFIX(frameParameter_unsupported): return "Unsupported frame parameter";
    case PREFIX(frameParameter_windowTooLarge): return "Frame requires too much memory for decoding";
    case PREFIX(corruption_detected): return "Data corruption detected";
    case PREFIX(checksum_wrong): return "Restored data doesn't match checksum";
    case PREFIX(literals_headerWrong): return "Header of Literals' block doesn't respect format specification";
    case PREFIX(parameter_unsupported): return "Unsupported parameter";
    case PREFIX(parameter_combination_unsupported): return "Unsupported combination of parameters";
    case PREFIX(parameter_outOfBound): return "Parameter is out of bound";
    case PREFIX(init_missing): return "Context should be init first";
    case PREFIX(memory_allocation): return "Allocation error : not enough memory";
    case PREFIX(workSpace_tooSmall): return "workSpace buffer is not large enough";
    case PREFIX(stage_wrong): return "Operation not authorized at current processing stage";
    case PREFIX(tableLog_tooLarge): return "tableLog requires too much memory : unsupported";
    case PREFIX(maxSymbolValue_tooLarge): return "Unsupported max Symbol Value : too large";
    case PREFIX(maxSymbolValue_tooSmall): return "Specified maxSymbolValue is too small";
    case PREFIX(stabilityCondition_notRespected): return "pledged buffer stability condition is not respected";
    case PREFIX(dictionary_corrupted): return "Dictionary is corrupted";
    case PREFIX(dictionary_wrong): return "Dictionary mismatch";
    case PREFIX(dictionaryCreation_failed): return "Cannot create Dictionary from provided samples";
    case PREFIX(dstSize_tooSmall): return "Destination buffer is too small";
    case PREFIX(srcSize_wrong): return "Src size is incorrect";
    case PREFIX(dstBuffer_null): return "Operation on NULL destination buffer";
    case PREFIX(noForwardProgress_destFull): return "Operation made no progress over multiple calls, due to output buffer being full";
    case PREFIX(noForwardProgress_inputEmpty): return "Operation made no progress over multiple calls, due to input being empty";
        /* following error codes are not stable and may be removed or changed in a future version */
    case PREFIX(frameIndex_tooLarge): return "Frame index is too large";
    case PREFIX(seekableIO): return "An I/O error occurred when reading/seeking";
    case PREFIX(dstBuffer_wrong): return "Destination buffer is wrong";
    case PREFIX(srcBuffer_wrong): return "Source buffer is wrong";
    case PREFIX(sequenceProducer_failed): return "Block-level external sequence producer returned an error code";
    case PREFIX(externalSequences_invalid): return "External sequences are not valid";
    case PREFIX(maxCode):
    default: return notErrorCode;
    }
#endif
}
/**** ended inlining common/error_private.c ****/
/**** start inlining common/fse_decompress.c ****/
/* ******************************************************************
 * FSE : Finite State Entropy decoder
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 *  You can contact the author at :
 *  - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *  - Public forum : https://groups.google.com/forum/#!forum/lz4c
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */


/* **************************************************************
*  Includes
****************************************************************/
/**** skipping file: debug.h ****/
/**** skipping file: bitstream.h ****/
/**** skipping file: compiler.h ****/
#define FSE_STATIC_LINKING_ONLY
/**** skipping file: fse.h ****/
/**** skipping file: error_private.h ****/
/**** skipping file: zstd_deps.h ****/
/**** skipping file: bits.h ****/


/* **************************************************************
*  Error Management
****************************************************************/
#define FSE_isError ERR_isError
#define FSE_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)   /* use only *after* variable declarations */


/* **************************************************************
*  Templates
****************************************************************/
/*
  designed to be included
  for type-specific functions (template emulation in C)
  Objective is to write these functions only once, for improved maintenance
*/

/* safety checks */
#ifndef FSE_FUNCTION_EXTENSION
#  error "FSE_FUNCTION_EXTENSION must be defined"
#endif
#ifndef FSE_FUNCTION_TYPE
#  error "FSE_FUNCTION_TYPE must be defined"
#endif

/* Function names */
#define FSE_CAT(X,Y) X##Y
#define FSE_FUNCTION_NAME(X,Y) FSE_CAT(X,Y)
#define FSE_TYPE_NAME(X,Y) FSE_CAT(X,Y)

static size_t FSE_buildDTable_internal(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize)
{
    void* const tdPtr = dt+1;   /* because *dt is unsigned, 32-bits aligned on 32-bits */
    FSE_DECODE_TYPE* const tableDecode = (FSE_DECODE_TYPE*) (tdPtr);
    U16* symbolNext = (U16*)workSpace;
    BYTE* spread = (BYTE*)(symbolNext + maxSymbolValue + 1);

    U32 const maxSV1 = maxSymbolValue + 1;
    U32 const tableSize = 1 << tableLog;
    U32 highThreshold = tableSize-1;

    /* Sanity Checks */
    if (FSE_BUILD_DTABLE_WKSP_SIZE(tableLog, maxSymbolValue) > wkspSize) return ERROR(maxSymbolValue_tooLarge);
    if (maxSymbolValue > FSE_MAX_SYMBOL_VALUE) return ERROR(maxSymbolValue_tooLarge);
    if (tableLog > FSE_MAX_TABLELOG) return ERROR(tableLog_tooLarge);

    /* Init, lay down lowprob symbols */
    {   FSE_DTableHeader DTableH;
        DTableH.tableLog = (U16)tableLog;
        DTableH.fastMode = 1;
        {   S16 const largeLimit= (S16)(1 << (tableLog-1));
            U32 s;
            for (s=0; s<maxSV1; s++) {
                if (normalizedCounter[s]==-1) {
                    tableDecode[highThreshold--].symbol = (FSE_FUNCTION_TYPE)s;
                    symbolNext[s] = 1;
                } else {
                    if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
                    symbolNext[s] = (U16)normalizedCounter[s];
        }   }   }
        ZSTD_memcpy(dt, &DTableH, sizeof(DTableH));
    }

    /* Spread symbols */
    if (highThreshold == tableSize - 1) {
        size_t const tableMask = tableSize-1;
        size_t const step = FSE_TABLESTEP(tableSize);
        /* First lay down the symbols in order.
         * We use a uint64_t to lay down 8 bytes at a time. This reduces branch
         * misses since small blocks generally have small table logs, so nearly
         * all symbols have counts <= 8. We ensure we have 8 bytes at the end of
         * our buffer to handle the over-write.
         */
        {   U64 const add = 0x0101010101010101ull;
            size_t pos = 0;
            U64 sv = 0;
            U32 s;
            for (s=0; s<maxSV1; ++s, sv += add) {
                int i;
                int const n = normalizedCounter[s];
                MEM_write64(spread + pos, sv);
                for (i = 8; i < n; i += 8) {
                    MEM_write64(spread + pos + i, sv);
                }
                pos += (size_t)n;
        }   }
        /* Now we spread those positions across the table.
         * The benefit of doing it in two stages is that we avoid the
         * variable size inner loop, which caused lots of branch misses.
         * Now we can run through all the positions without any branch misses.
         * We unroll the loop twice, since that is what empirically worked best.
         */
        {
            size_t position = 0;
            size_t s;
            size_t const unroll = 2;
            assert(tableSize % unroll == 0); /* FSE_MIN_TABLELOG is 5 */
            for (s = 0; s < (size_t)tableSize; s += unroll) {
                size_t u;
                for (u = 0; u < unroll; ++u) {
                    size_t const uPosition = (position + (u * step)) & tableMask;
                    tableDecode[uPosition].symbol = spread[s + u];
                }
                position = (position + (unroll * step)) & tableMask;
            }
            assert(position == 0);
        }
    } else {
        U32 const tableMask = tableSize-1;
        U32 const step = FSE_TABLESTEP(tableSize);
        U32 s, position = 0;
        for (s=0; s<maxSV1; s++) {
            int i;
            for (i=0; i<normalizedCounter[s]; i++) {
                tableDecode[position].symbol = (FSE_FUNCTION_TYPE)s;
                position = (position + step) & tableMask;
                while (position > highThreshold) position = (position + step) & tableMask;   /* lowprob area */
        }   }
        if (position!=0) return ERROR(GENERIC);   /* position must reach all cells once, otherwise normalizedCounter is incorrect */
    }

    /* Build Decoding table */
    {   U32 u;
        for (u=0; u<tableSize; u++) {
            FSE_FUNCTION_TYPE const symbol = (FSE_FUNCTION_TYPE)(tableDecode[u].symbol);
            U32 const nextState = symbolNext[symbol]++;
            tableDecode[u].nbBits = (BYTE) (tableLog - ZSTD_highbit32(nextState) );
            tableDecode[u].newState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
    }   }

    return 0;
}

size_t FSE_buildDTable_wksp(FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog, void* workSpace, size_t wkspSize)
{
    return FSE_buildDTable_internal(dt, normalizedCounter, maxSymbolValue, tableLog, workSpace, wkspSize);
}


#ifndef FSE_COMMONDEFS_ONLY

/*-*******************************************************
*  Decompression (Byte symbols)
*********************************************************/

FORCE_INLINE_TEMPLATE size_t FSE_decompress_usingDTable_generic(
          void* dst, size_t maxDstSize,
    const void* cSrc, size_t cSrcSize,
    const FSE_DTable* dt, const unsigned fast)
{
    BYTE* const ostart = (BYTE*) dst;
    BYTE* op = ostart;
    BYTE* const omax = op + maxDstSize;
    BYTE* const olimit = omax-3;

    BIT_DStream_t bitD;
    FSE_DState_t state1;
    FSE_DState_t state2;

    /* Init */
    CHECK_F(BIT_initDStream(&bitD, cSrc, cSrcSize));

    FSE_initDState(&state1, &bitD, dt);
    FSE_initDState(&state2, &bitD, dt);

#define FSE_GETSYMBOL(statePtr) fast ? FSE_decodeSymbolFast(statePtr, &bitD) : FSE_decodeSymbol(statePtr, &bitD)

    /* 4 symbols per loop */
    for ( ; (BIT_reloadDStream(&bitD)==BIT_DStream_unfinished) & (op<olimit) ; op+=4) {
        op[0] = FSE_GETSYMBOL(&state1);

        if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
            BIT_reloadDStream(&bitD);

        op[1] = FSE_GETSYMBOL(&state2);

        if (FSE_MAX_TABLELOG*4+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
            { if (BIT_reloadDStream(&bitD) > BIT_DStream_unfinished) { op+=2; break; } }

        op[2] = FSE_GETSYMBOL(&state1);

        if (FSE_MAX_TABLELOG*2+7 > sizeof(bitD.bitContainer)*8)    /* This test must be static */
            BIT_reloadDStream(&bitD);

        op[3] = FSE_GETSYMBOL(&state2);
    }

    /* tail */
    /* note : BIT_reloadDStream(&bitD) >= FSE_DStream_partiallyFilled; Ends at exactly BIT_DStream_completed */
    while (1) {
        if (op>(omax-2)) return ERROR(dstSize_tooSmall);
        *op++ = FSE_GETSYMBOL(&state1);
        if (BIT_reloadDStream(&bitD)==BIT_DStream_overflow) {
            *op++ = FSE_GETSYMBOL(&state2);
            break;
        }

        if (op>(omax-2)) return ERROR(dstSize_tooSmall);
        *op++ = FSE_GETSYMBOL(&state2);
        if (BIT_reloadDStream(&bitD)==BIT_DStream_overflow) {
            *op++ = FSE_GETSYMBOL(&state1);
            break;
    }   }

    assert(op >= ostart);
    return (size_t)(op-ostart);
}

typedef struct {
    short ncount[FSE_MAX_SYMBOL_VALUE + 1];
} FSE_DecompressWksp;


FORCE_INLINE_TEMPLATE size_t FSE_decompress_wksp_body(
        void* dst, size_t dstCapacity,
        const void* cSrc, size_t cSrcSize,
        unsigned maxLog, void* workSpace, size_t wkspSize,
        int bmi2)
{
    const BYTE* const istart = (const BYTE*)cSrc;
    const BYTE* ip = istart;
    unsigned tableLog;
    unsigned maxSymbolValue = FSE_MAX_SYMBOL_VALUE;
    FSE_DecompressWksp* const wksp = (FSE_DecompressWksp*)workSpace;
    size_t const dtablePos = sizeof(FSE_DecompressWksp) / sizeof(FSE_DTable);
    FSE_DTable* const dtable = (FSE_DTable*)workSpace + dtablePos;

    FSE_STATIC_ASSERT((FSE_MAX_SYMBOL_VALUE + 1) % 2 == 0);
    if (wkspSize < sizeof(*wksp)) return ERROR(GENERIC);

    /* correct offset to dtable depends on this property */
    FSE_STATIC_ASSERT(sizeof(FSE_DecompressWksp) % sizeof(FSE_DTable) == 0);

    /* normal FSE decoding mode */
    {   size_t const NCountLength =
            FSE_readNCount_bmi2(wksp->ncount, &maxSymbolValue, &tableLog, istart, cSrcSize, bmi2);
        if (FSE_isError(NCountLength)) return NCountLength;
        if (tableLog > maxLog) return ERROR(tableLog_tooLarge);
        assert(NCountLength <= cSrcSize);
        ip += NCountLength;
        cSrcSize -= NCountLength;
    }

    if (FSE_DECOMPRESS_WKSP_SIZE(tableLog, maxSymbolValue) > wkspSize) return ERROR(tableLog_tooLarge);
    assert(sizeof(*wksp) + FSE_DTABLE_SIZE(tableLog) <= wkspSize);
    workSpace = (BYTE*)workSpace + sizeof(*wksp) + FSE_DTABLE_SIZE(tableLog);
    wkspSize -= sizeof(*wksp) + FSE_DTABLE_SIZE(tableLog);

    CHECK_F( FSE_buildDTable_internal(dtable, wksp->ncount, maxSymbolValue, tableLog, workSpace, wkspSize) );

    {
        const void* ptr = dtable;
        const FSE_DTableHeader* DTableH = (const FSE_DTableHeader*)ptr;
        const U32 fastMode = DTableH->fastMode;

        /* select fast mode (static) */
        if (fastMode) return FSE_decompress_usingDTable_generic(dst, dstCapacity, ip, cSrcSize, dtable, 1);
        return FSE_decompress_usingDTable_generic(dst, dstCapacity, ip, cSrcSize, dtable, 0);
    }
}

/* Avoids the FORCE_INLINE of the _body() function. */
static size_t FSE_decompress_wksp_body_default(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, unsigned maxLog, void* workSpace, size_t wkspSize)
{
    return FSE_decompress_wksp_body(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize, 0);
}

#if DYNAMIC_BMI2
BMI2_TARGET_ATTRIBUTE static size_t FSE_decompress_wksp_body_bmi2(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, unsigned maxLog, void* workSpace, size_t wkspSize)
{
    return FSE_decompress_wksp_body(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize, 1);
}
#endif

size_t FSE_decompress_wksp_bmi2(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, unsigned maxLog, void* workSpace, size_t wkspSize, int bmi2)
{
#if DYNAMIC_BMI2
    if (bmi2) {
        return FSE_decompress_wksp_body_bmi2(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize);
    }
#endif
    (void)bmi2;
    return FSE_decompress_wksp_body_default(dst, dstCapacity, cSrc, cSrcSize, maxLog, workSpace, wkspSize);
}

#endif   /* FSE_COMMONDEFS_ONLY */
/**** ended inlining common/fse_decompress.c ****/
/**** start inlining common/zstd_common.c ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */



/*-*************************************
*  Dependencies
***************************************/
#define ZSTD_DEPS_NEED_MALLOC
/**** skipping file: error_private.h ****/
/**** start inlining zstd_internal.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_CCOMMON_H_MODULE
#define ZSTD_CCOMMON_H_MODULE

/* this module contains definitions which must be identical
 * across compression, decompression and dictBuilder.
 * It also contains a few functions useful to at least 2 of them
 * and which benefit from being inlined */

/*-*************************************
*  Dependencies
***************************************/
/**** skipping file: compiler.h ****/
/**** start inlining cpu.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_COMMON_CPU_H
#define ZSTD_COMMON_CPU_H

/**
 * Implementation taken from folly/CpuId.h
 * https://github.com/facebook/folly/blob/master/folly/CpuId.h
 */

/**** skipping file: mem.h ****/

#ifdef _MSC_VER
#include <intrin.h>
#endif

typedef struct {
    U32 f1c;
    U32 f1d;
    U32 f7b;
    U32 f7c;
} ZSTD_cpuid_t;

MEM_STATIC ZSTD_cpuid_t ZSTD_cpuid(void) {
    U32 f1c = 0;
    U32 f1d = 0;
    U32 f7b = 0;
    U32 f7c = 0;
#if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86))
#if !defined(__clang__)
    int reg[4];
    __cpuid((int*)reg, 0);
    {
        int const n = reg[0];
        if (n >= 1) {
            __cpuid((int*)reg, 1);
            f1c = (U32)reg[2];
            f1d = (U32)reg[3];
        }
        if (n >= 7) {
            __cpuidex((int*)reg, 7, 0);
            f7b = (U32)reg[1];
            f7c = (U32)reg[2];
        }
    }
#else
    /* Clang compiler has a bug (fixed in https://reviews.llvm.org/D101338) in
     * which the `__cpuid` intrinsic does not save and restore `rbx` as it needs
     * to due to being a reserved register. So in that case, do the `cpuid`
     * ourselves. Clang supports inline assembly anyway.
     */
    U32 n;
    __asm__(
        "pushq %%rbx\n\t"
        "cpuid\n\t"
        "popq %%rbx\n\t"
        : "=a"(n)
        : "a"(0)
        : "rcx", "rdx");
    if (n >= 1) {
      U32 f1a;
      __asm__(
          "pushq %%rbx\n\t"
          "cpuid\n\t"
          "popq %%rbx\n\t"
          : "=a"(f1a), "=c"(f1c), "=d"(f1d)
          : "a"(1)
          :);
    }
    if (n >= 7) {
      __asm__(
          "pushq %%rbx\n\t"
          "cpuid\n\t"
          "movq %%rbx, %%rax\n\t"
          "popq %%rbx"
          : "=a"(f7b), "=c"(f7c)
          : "a"(7), "c"(0)
          : "rdx");
    }
#endif
#elif defined(__i386__) && defined(__PIC__) && !defined(__clang__) && defined(__GNUC__)
    /* The following block like the normal cpuid branch below, but gcc
     * reserves ebx for use of its pic register so we must specially
     * handle the save and restore to avoid clobbering the register
     */
    U32 n;
    __asm__(
        "pushl %%ebx\n\t"
        "cpuid\n\t"
        "popl %%ebx\n\t"
        : "=a"(n)
        : "a"(0)
        : "ecx", "edx");
    if (n >= 1) {
      U32 f1a;
      __asm__(
          "pushl %%ebx\n\t"
          "cpuid\n\t"
          "popl %%ebx\n\t"
          : "=a"(f1a), "=c"(f1c), "=d"(f1d)
          : "a"(1));
    }
    if (n >= 7) {
      __asm__(
          "pushl %%ebx\n\t"
          "cpuid\n\t"
          "movl %%ebx, %%eax\n\t"
          "popl %%ebx"
          : "=a"(f7b), "=c"(f7c)
          : "a"(7), "c"(0)
          : "edx");
    }
#elif defined(__x86_64__) || defined(_M_X64) || defined(__i386__)
    U32 n;
    __asm__("cpuid" : "=a"(n) : "a"(0) : "ebx", "ecx", "edx");
    if (n >= 1) {
      U32 f1a;
      __asm__("cpuid" : "=a"(f1a), "=c"(f1c), "=d"(f1d) : "a"(1) : "ebx");
    }
    if (n >= 7) {
      U32 f7a;
      __asm__("cpuid"
              : "=a"(f7a), "=b"(f7b), "=c"(f7c)
              : "a"(7), "c"(0)
              : "edx");
    }
#endif
    {
        ZSTD_cpuid_t cpuid;
        cpuid.f1c = f1c;
        cpuid.f1d = f1d;
        cpuid.f7b = f7b;
        cpuid.f7c = f7c;
        return cpuid;
    }
}

#define X(name, r, bit)                                                        \
  MEM_STATIC int ZSTD_cpuid_##name(ZSTD_cpuid_t const cpuid) {                 \
    return ((cpuid.r) & (1U << bit)) != 0;                                     \
  }

/* cpuid(1): Processor Info and Feature Bits. */
#define C(name, bit) X(name, f1c, bit)
  C(sse3, 0)
  C(pclmuldq, 1)
  C(dtes64, 2)
  C(monitor, 3)
  C(dscpl, 4)
  C(vmx, 5)
  C(smx, 6)
  C(eist, 7)
  C(tm2, 8)
  C(ssse3, 9)
  C(cnxtid, 10)
  C(fma, 12)
  C(cx16, 13)
  C(xtpr, 14)
  C(pdcm, 15)
  C(pcid, 17)
  C(dca, 18)
  C(sse41, 19)
  C(sse42, 20)
  C(x2apic, 21)
  C(movbe, 22)
  C(popcnt, 23)
  C(tscdeadline, 24)
  C(aes, 25)
  C(xsave, 26)
  C(osxsave, 27)
  C(avx, 28)
  C(f16c, 29)
  C(rdrand, 30)
#undef C
#define D(name, bit) X(name, f1d, bit)
  D(fpu, 0)
  D(vme, 1)
  D(de, 2)
  D(pse, 3)
  D(tsc, 4)
  D(msr, 5)
  D(pae, 6)
  D(mce, 7)
  D(cx8, 8)
  D(apic, 9)
  D(sep, 11)
  D(mtrr, 12)
  D(pge, 13)
  D(mca, 14)
  D(cmov, 15)
  D(pat, 16)
  D(pse36, 17)
  D(psn, 18)
  D(clfsh, 19)
  D(ds, 21)
  D(acpi, 22)
  D(mmx, 23)
  D(fxsr, 24)
  D(sse, 25)
  D(sse2, 26)
  D(ss, 27)
  D(htt, 28)
  D(tm, 29)
  D(pbe, 31)
#undef D

/* cpuid(7): Extended Features. */
#define B(name, bit) X(name, f7b, bit)
  B(bmi1, 3)
  B(hle, 4)
  B(avx2, 5)
  B(smep, 7)
  B(bmi2, 8)
  B(erms, 9)
  B(invpcid, 10)
  B(rtm, 11)
  B(mpx, 14)
  B(avx512f, 16)
  B(avx512dq, 17)
  B(rdseed, 18)
  B(adx, 19)
  B(smap, 20)
  B(avx512ifma, 21)
  B(pcommit, 22)
  B(clflushopt, 23)
  B(clwb, 24)
  B(avx512pf, 26)
  B(avx512er, 27)
  B(avx512cd, 28)
  B(sha, 29)
  B(avx512bw, 30)
  B(avx512vl, 31)
#undef B
#define C(name, bit) X(name, f7c, bit)
  C(prefetchwt1, 0)
  C(avx512vbmi, 1)
#undef C

#undef X

#endif /* ZSTD_COMMON_CPU_H */
/**** ended inlining cpu.h ****/
/**** skipping file: mem.h ****/
/**** skipping file: debug.h ****/
/**** skipping file: error_private.h ****/
#define ZSTD_STATIC_LINKING_ONLY
/**** start inlining ../zstd.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */
#if defined (__cplusplus)
extern "C" {
#endif

#ifndef ZSTD_H_235446
#define ZSTD_H_235446

/* ======   Dependencies   ======*/
#include <limits.h>   /* INT_MAX */
#include <stddef.h>   /* size_t */


/* =====   ZSTDLIB_API : control library symbols visibility   ===== */
#ifndef ZSTDLIB_VISIBLE
   /* Backwards compatibility with old macro name */
#  ifdef ZSTDLIB_VISIBILITY
#    define ZSTDLIB_VISIBLE ZSTDLIB_VISIBILITY
#  elif defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
#    define ZSTDLIB_VISIBLE __attribute__ ((visibility ("default")))
#  else
#    define ZSTDLIB_VISIBLE
#  endif
#endif

#ifndef ZSTDLIB_HIDDEN
#  if defined(__GNUC__) && (__GNUC__ >= 4) && !defined(__MINGW32__)
#    define ZSTDLIB_HIDDEN __attribute__ ((visibility ("hidden")))
#  else
#    define ZSTDLIB_HIDDEN
#  endif
#endif

#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
#  define ZSTDLIB_API __declspec(dllexport) ZSTDLIB_VISIBLE
#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
#  define ZSTDLIB_API __declspec(dllimport) ZSTDLIB_VISIBLE /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
#else
#  define ZSTDLIB_API ZSTDLIB_VISIBLE
#endif

/* Deprecation warnings :
 * Should these warnings be a problem, it is generally possible to disable them,
 * typically with -Wno-deprecated-declarations for gcc or _CRT_SECURE_NO_WARNINGS in Visual.
 * Otherwise, it's also possible to define ZSTD_DISABLE_DEPRECATE_WARNINGS.
 */
#ifdef ZSTD_DISABLE_DEPRECATE_WARNINGS
#  define ZSTD_DEPRECATED(message) /* disable deprecation warnings */
#else
#  if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
#    define ZSTD_DEPRECATED(message) [[deprecated(message)]]
#  elif (defined(GNUC) && (GNUC > 4 || (GNUC == 4 && GNUC_MINOR >= 5))) || defined(__clang__)
#    define ZSTD_DEPRECATED(message) __attribute__((deprecated(message)))
#  elif defined(__GNUC__) && (__GNUC__ >= 3)
#    define ZSTD_DEPRECATED(message) __attribute__((deprecated))
#  elif defined(_MSC_VER)
#    define ZSTD_DEPRECATED(message) __declspec(deprecated(message))
#  else
#    pragma message("WARNING: You need to implement ZSTD_DEPRECATED for this compiler")
#    define ZSTD_DEPRECATED(message)
#  endif
#endif /* ZSTD_DISABLE_DEPRECATE_WARNINGS */


/*******************************************************************************
  Introduction

  zstd, short for Zstandard, is a fast lossless compression algorithm, targeting
  real-time compression scenarios at zlib-level and better compression ratios.
  The zstd compression library provides in-memory compression and decompression
  functions.

  The library supports regular compression levels from 1 up to ZSTD_maxCLevel(),
  which is currently 22. Levels >= 20, labeled `--ultra`, should be used with
  caution, as they require more memory. The library also offers negative
  compression levels, which extend the range of speed vs. ratio preferences.
  The lower the level, the faster the speed (at the cost of compression).

  Compression can be done in:
    - a single step (described as Simple API)
    - a single step, reusing a context (described as Explicit context)
    - unbounded multiple steps (described as Streaming compression)

  The compression ratio achievable on small data can be highly improved using
  a dictionary. Dictionary compression can be performed in:
    - a single step (described as Simple dictionary API)
    - a single step, reusing a dictionary (described as Bulk-processing
      dictionary API)

  Advanced experimental functions can be accessed using
  `#define ZSTD_STATIC_LINKING_ONLY` before including zstd.h.

  Advanced experimental APIs should never be used with a dynamically-linked
  library. They are not "stable"; their definitions or signatures may change in
  the future. Only static linking is allowed.
*******************************************************************************/

/*------   Version   ------*/
#define ZSTD_VERSION_MAJOR    1
#define ZSTD_VERSION_MINOR    5
#define ZSTD_VERSION_RELEASE  6
#define ZSTD_VERSION_NUMBER  (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)

/*! ZSTD_versionNumber() :
 *  Return runtime library version, the value is (MAJOR*100*100 + MINOR*100 + RELEASE). */
ZSTDLIB_API unsigned ZSTD_versionNumber(void);

#define ZSTD_LIB_VERSION ZSTD_VERSION_MAJOR.ZSTD_VERSION_MINOR.ZSTD_VERSION_RELEASE
#define ZSTD_QUOTE(str) #str
#define ZSTD_EXPAND_AND_QUOTE(str) ZSTD_QUOTE(str)
#define ZSTD_VERSION_STRING ZSTD_EXPAND_AND_QUOTE(ZSTD_LIB_VERSION)

/*! ZSTD_versionString() :
 *  Return runtime library version, like "1.4.5". Requires v1.3.0+. */
ZSTDLIB_API const char* ZSTD_versionString(void);

/* *************************************
 *  Default constant
 ***************************************/
#ifndef ZSTD_CLEVEL_DEFAULT
#  define ZSTD_CLEVEL_DEFAULT 3
#endif

/* *************************************
 *  Constants
 ***************************************/

/* All magic numbers are supposed read/written to/from files/memory using little-endian convention */
#define ZSTD_MAGICNUMBER            0xFD2FB528    /* valid since v0.8.0 */
#define ZSTD_MAGIC_DICTIONARY       0xEC30A437    /* valid since v0.7.0 */
#define ZSTD_MAGIC_SKIPPABLE_START  0x184D2A50    /* all 16 values, from 0x184D2A50 to 0x184D2A5F, signal the beginning of a skippable frame */
#define ZSTD_MAGIC_SKIPPABLE_MASK   0xFFFFFFF0

#define ZSTD_BLOCKSIZELOG_MAX  17
#define ZSTD_BLOCKSIZE_MAX     (1<<ZSTD_BLOCKSIZELOG_MAX)


/***************************************
*  Simple API
***************************************/
/*! ZSTD_compress() :
 *  Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
 *  NOTE: Providing `dstCapacity >= ZSTD_compressBound(srcSize)` guarantees that zstd will have
 *        enough space to successfully compress the data.
 *  @return : compressed size written into `dst` (<= `dstCapacity),
 *            or an error code if it fails (which can be tested using ZSTD_isError()). */
ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize,
                                  int compressionLevel);

/*! ZSTD_decompress() :
 *  `compressedSize` : must be the _exact_ size of some number of compressed and/or skippable frames.
 *  `dstCapacity` is an upper bound of originalSize to regenerate.
 *  If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data.
 *  @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
 *            or an errorCode if it fails (which can be tested using ZSTD_isError()). */
ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity,
                              const void* src, size_t compressedSize);

/*! ZSTD_getFrameContentSize() : requires v1.3.0+
 *  `src` should point to the start of a ZSTD encoded frame.
 *  `srcSize` must be at least as large as the frame header.
 *            hint : any size >= `ZSTD_frameHeaderSize_max` is large enough.
 *  @return : - decompressed size of `src` frame content, if known
 *            - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
 *            - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
 *   note 1 : a 0 return value means the frame is valid but "empty".
 *   note 2 : decompressed size is an optional field, it may not be present, typically in streaming mode.
 *            When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
 *            In which case, it's necessary to use streaming mode to decompress data.
 *            Optionally, application can rely on some implicit limit,
 *            as ZSTD_decompress() only needs an upper bound of decompressed size.
 *            (For example, data could be necessarily cut into blocks <= 16 KB).
 *   note 3 : decompressed size is always present when compression is completed using single-pass functions,
 *            such as ZSTD_compress(), ZSTD_compressCCtx() ZSTD_compress_usingDict() or ZSTD_compress_usingCDict().
 *   note 4 : decompressed size can be very large (64-bits value),
 *            potentially larger than what local system can handle as a single memory segment.
 *            In which case, it's necessary to use streaming mode to decompress data.
 *   note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
 *            Always ensure return value fits within application's authorized limits.
 *            Each application can set its own limits.
 *   note 6 : This function replaces ZSTD_getDecompressedSize() */
#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
#define ZSTD_CONTENTSIZE_ERROR   (0ULL - 2)
ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);

/*! ZSTD_getDecompressedSize() :
 *  NOTE: This function is now obsolete, in favor of ZSTD_getFrameContentSize().
 *  Both functions work the same way, but ZSTD_getDecompressedSize() blends
 *  "empty", "unknown" and "error" results to the same return value (0),
 *  while ZSTD_getFrameContentSize() gives them separate return values.
 * @return : decompressed size of `src` frame content _if known and not empty_, 0 otherwise. */
ZSTD_DEPRECATED("Replaced by ZSTD_getFrameContentSize")
ZSTDLIB_API
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);

/*! ZSTD_findFrameCompressedSize() : Requires v1.4.0+
 * `src` should point to the start of a ZSTD frame or skippable frame.
 * `srcSize` must be >= first frame size
 * @return : the compressed size of the first frame starting at `src`,
 *           suitable to pass as `srcSize` to `ZSTD_decompress` or similar,
 *        or an error code if input is invalid */
ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);


/*======  Helper functions  ======*/
/* ZSTD_compressBound() :
 * maximum compressed size in worst case single-pass scenario.
 * When invoking `ZSTD_compress()` or any other one-pass compression function,
 * it's recommended to provide @dstCapacity >= ZSTD_compressBound(srcSize)
 * as it eliminates one potential failure scenario,
 * aka not enough room in dst buffer to write the compressed frame.
 * Note : ZSTD_compressBound() itself can fail, if @srcSize > ZSTD_MAX_INPUT_SIZE .
 *        In which case, ZSTD_compressBound() will return an error code
 *        which can be tested using ZSTD_isError().
 *
 * ZSTD_COMPRESSBOUND() :
 * same as ZSTD_compressBound(), but as a macro.
 * It can be used to produce constants, which can be useful for static allocation,
 * for example to size a static array on stack.
 * Will produce constant value 0 if srcSize too large.
 */
#define ZSTD_MAX_INPUT_SIZE ((sizeof(size_t)==8) ? 0xFF00FF00FF00FF00ULL : 0xFF00FF00U)
#define ZSTD_COMPRESSBOUND(srcSize)   (((size_t)(srcSize) >= ZSTD_MAX_INPUT_SIZE) ? 0 : (srcSize) + ((srcSize)>>8) + (((srcSize) < (128<<10)) ? (((128<<10) - (srcSize)) >> 11) /* margin, from 64 to 0 */ : 0))  /* this formula ensures that bound(A) + bound(B) <= bound(A+B) as long as A and B >= 128 KB */
ZSTDLIB_API size_t ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case single-pass scenario */
/* ZSTD_isError() :
 * Most ZSTD_* functions returning a size_t value can be tested for error,
 * using ZSTD_isError().
 * @return 1 if error, 0 otherwise
 */
ZSTDLIB_API unsigned    ZSTD_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
ZSTDLIB_API const char* ZSTD_getErrorName(size_t code);     /*!< provides readable string from an error code */
ZSTDLIB_API int         ZSTD_minCLevel(void);               /*!< minimum negative compression level allowed, requires v1.4.0+ */
ZSTDLIB_API int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
ZSTDLIB_API int         ZSTD_defaultCLevel(void);           /*!< default compression level, specified by ZSTD_CLEVEL_DEFAULT, requires v1.5.0+ */


/***************************************
*  Explicit context
***************************************/
/*= Compression context
 *  When compressing many times,
 *  it is recommended to allocate a context just once,
 *  and reuse it for each successive compression operation.
 *  This will make workload friendlier for system's memory.
 *  Note : re-using context is just a speed / resource optimization.
 *         It doesn't change the compression ratio, which remains identical.
 *  Note 2 : In multi-threaded environments,
 *         use one different context per thread for parallel execution.
 */
typedef struct ZSTD_CCtx_s ZSTD_CCtx;
ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx(void);
ZSTDLIB_API size_t     ZSTD_freeCCtx(ZSTD_CCtx* cctx);  /* accept NULL pointer */

/*! ZSTD_compressCCtx() :
 *  Same as ZSTD_compress(), using an explicit ZSTD_CCtx.
 *  Important : in order to mirror `ZSTD_compress()` behavior,
 *  this function compresses at the requested compression level,
 *  __ignoring any other advanced parameter__ .
 *  If any advanced parameter was set using the advanced API,
 *  they will all be reset. Only `compressionLevel` remains.
 */
ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* cctx,
                                     void* dst, size_t dstCapacity,
                               const void* src, size_t srcSize,
                                     int compressionLevel);

/*= Decompression context
 *  When decompressing many times,
 *  it is recommended to allocate a context only once,
 *  and reuse it for each successive compression operation.
 *  This will make workload friendlier for system's memory.
 *  Use one context per thread for parallel execution. */
typedef struct ZSTD_DCtx_s ZSTD_DCtx;
ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx(void);
ZSTDLIB_API size_t     ZSTD_freeDCtx(ZSTD_DCtx* dctx);  /* accept NULL pointer */

/*! ZSTD_decompressDCtx() :
 *  Same as ZSTD_decompress(),
 *  requires an allocated ZSTD_DCtx.
 *  Compatible with sticky parameters (see below).
 */
ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx,
                                       void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize);


/*********************************************
*  Advanced compression API (Requires v1.4.0+)
**********************************************/

/* API design :
 *   Parameters are pushed one by one into an existing context,
 *   using ZSTD_CCtx_set*() functions.
 *   Pushed parameters are sticky : they are valid for next compressed frame, and any subsequent frame.
 *   "sticky" parameters are applicable to `ZSTD_compress2()` and `ZSTD_compressStream*()` !
 *   __They do not apply to one-shot variants such as ZSTD_compressCCtx()__ .
 *
 *   It's possible to reset all parameters to "default" using ZSTD_CCtx_reset().
 *
 *   This API supersedes all other "advanced" API entry points in the experimental section.
 *   In the future, we expect to remove API entry points from experimental which are redundant with this API.
 */


/* Compression strategies, listed from fastest to strongest */
typedef enum { ZSTD_fast=1,
               ZSTD_dfast=2,
               ZSTD_greedy=3,
               ZSTD_lazy=4,
               ZSTD_lazy2=5,
               ZSTD_btlazy2=6,
               ZSTD_btopt=7,
               ZSTD_btultra=8,
               ZSTD_btultra2=9
               /* note : new strategies _might_ be added in the future.
                         Only the order (from fast to strong) is guaranteed */
} ZSTD_strategy;

typedef enum {

    /* compression parameters
     * Note: When compressing with a ZSTD_CDict these parameters are superseded
     * by the parameters used to construct the ZSTD_CDict.
     * See ZSTD_CCtx_refCDict() for more info (superseded-by-cdict). */
    ZSTD_c_compressionLevel=100, /* Set compression parameters according to pre-defined cLevel table.
                              * Note that exact compression parameters are dynamically determined,
                              * depending on both compression level and srcSize (when known).
                              * Default level is ZSTD_CLEVEL_DEFAULT==3.
                              * Special: value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT.
                              * Note 1 : it's possible to pass a negative compression level.
                              * Note 2 : setting a level does not automatically set all other compression parameters
                              *   to default. Setting this will however eventually dynamically impact the compression
                              *   parameters which have not been manually set. The manually set
                              *   ones will 'stick'. */
    /* Advanced compression parameters :
     * It's possible to pin down compression parameters to some specific values.
     * In which case, these values are no longer dynamically selected by the compressor */
    ZSTD_c_windowLog=101,    /* Maximum allowed back-reference distance, expressed as power of 2.
                              * This will set a memory budget for streaming decompression,
                              * with larger values requiring more memory
                              * and typically compressing more.
                              * Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
                              * Special: value 0 means "use default windowLog".
                              * Note: Using a windowLog greater than ZSTD_WINDOWLOG_LIMIT_DEFAULT
                              *       requires explicitly allowing such size at streaming decompression stage. */
    ZSTD_c_hashLog=102,      /* Size of the initial probe table, as a power of 2.
                              * Resulting memory usage is (1 << (hashLog+2)).
                              * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
                              * Larger tables improve compression ratio of strategies <= dFast,
                              * and improve speed of strategies > dFast.
                              * Special: value 0 means "use default hashLog". */
    ZSTD_c_chainLog=103,     /* Size of the multi-probe search table, as a power of 2.
                              * Resulting memory usage is (1 << (chainLog+2)).
                              * Must be clamped between ZSTD_CHAINLOG_MIN and ZSTD_CHAINLOG_MAX.
                              * Larger tables result in better and slower compression.
                              * This parameter is useless for "fast" strategy.
                              * It's still useful when using "dfast" strategy,
                              * in which case it defines a secondary probe table.
                              * Special: value 0 means "use default chainLog". */
    ZSTD_c_searchLog=104,    /* Number of search attempts, as a power of 2.
                              * More attempts result in better and slower compression.
                              * This parameter is useless for "fast" and "dFast" strategies.
                              * Special: value 0 means "use default searchLog". */
    ZSTD_c_minMatch=105,     /* Minimum size of searched matches.
                              * Note that Zstandard can still find matches of smaller size,
                              * it just tweaks its search algorithm to look for this size and larger.
                              * Larger values increase compression and decompression speed, but decrease ratio.
                              * Must be clamped between ZSTD_MINMATCH_MIN and ZSTD_MINMATCH_MAX.
                              * Note that currently, for all strategies < btopt, effective minimum is 4.
                              *                    , for all strategies > fast, effective maximum is 6.
                              * Special: value 0 means "use default minMatchLength". */
    ZSTD_c_targetLength=106, /* Impact of this field depends on strategy.
                              * For strategies btopt, btultra & btultra2:
                              *     Length of Match considered "good enough" to stop search.
                              *     Larger values make compression stronger, and slower.
                              * For strategy fast:
                              *     Distance between match sampling.
                              *     Larger values make compression faster, and weaker.
                              * Special: value 0 means "use default targetLength". */
    ZSTD_c_strategy=107,     /* See ZSTD_strategy enum definition.
                              * The higher the value of selected strategy, the more complex it is,
                              * resulting in stronger and slower compression.
                              * Special: value 0 means "use default strategy". */

    ZSTD_c_targetCBlockSize=130, /* v1.5.6+
                                  * Attempts to fit compressed block size into approximatively targetCBlockSize.
                                  * Bound by ZSTD_TARGETCBLOCKSIZE_MIN and ZSTD_TARGETCBLOCKSIZE_MAX.
                                  * Note that it's not a guarantee, just a convergence target (default:0).
                                  * No target when targetCBlockSize == 0.
                                  * This is helpful in low bandwidth streaming environments to improve end-to-end latency,
                                  * when a client can make use of partial documents (a prominent example being Chrome).
                                  * Note: this parameter is stable since v1.5.6.
                                  * It was present as an experimental parameter in earlier versions,
                                  * but it's not recommended using it with earlier library versions
                                  * due to massive performance regressions.
                                  */
    /* LDM mode parameters */
    ZSTD_c_enableLongDistanceMatching=160, /* Enable long distance matching.
                                     * This parameter is designed to improve compression ratio
                                     * for large inputs, by finding large matches at long distance.
                                     * It increases memory usage and window size.
                                     * Note: enabling this parameter increases default ZSTD_c_windowLog to 128 MB
                                     * except when expressly set to a different value.
                                     * Note: will be enabled by default if ZSTD_c_windowLog >= 128 MB and
                                     * compression strategy >= ZSTD_btopt (== compression level 16+) */
    ZSTD_c_ldmHashLog=161,   /* Size of the table for long distance matching, as a power of 2.
                              * Larger values increase memory usage and compression ratio,
                              * but decrease compression speed.
                              * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
                              * default: windowlog - 7.
                              * Special: value 0 means "automatically determine hashlog". */
    ZSTD_c_ldmMinMatch=162,  /* Minimum match size for long distance matcher.
                              * Larger/too small values usually decrease compression ratio.
                              * Must be clamped between ZSTD_LDM_MINMATCH_MIN and ZSTD_LDM_MINMATCH_MAX.
                              * Special: value 0 means "use default value" (default: 64). */
    ZSTD_c_ldmBucketSizeLog=163, /* Log size of each bucket in the LDM hash table for collision resolution.
                              * Larger values improve collision resolution but decrease compression speed.
                              * The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX.
                              * Special: value 0 means "use default value" (default: 3). */
    ZSTD_c_ldmHashRateLog=164, /* Frequency of inserting/looking up entries into the LDM hash table.
                              * Must be clamped between 0 and (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN).
                              * Default is MAX(0, (windowLog - ldmHashLog)), optimizing hash table usage.
                              * Larger values improve compression speed.
                              * Deviating far from default value will likely result in a compression ratio decrease.
                              * Special: value 0 means "automatically determine hashRateLog". */

    /* frame parameters */
    ZSTD_c_contentSizeFlag=200, /* Content size will be written into frame header _whenever known_ (default:1)
                              * Content size must be known at the beginning of compression.
                              * This is automatically the case when using ZSTD_compress2(),
                              * For streaming scenarios, content size must be provided with ZSTD_CCtx_setPledgedSrcSize() */
    ZSTD_c_checksumFlag=201, /* A 32-bits checksum of content is written at end of frame (default:0) */
    ZSTD_c_dictIDFlag=202,   /* When applicable, dictionary's ID is written into frame header (default:1) */

    /* multi-threading parameters */
    /* These parameters are only active if multi-threading is enabled (compiled with build macro ZSTD_MULTITHREAD).
     * Otherwise, trying to set any other value than default (0) will be a no-op and return an error.
     * In a situation where it's unknown if the linked library supports multi-threading or not,
     * setting ZSTD_c_nbWorkers to any value >= 1 and consulting the return value provides a quick way to check this property.
     */
    ZSTD_c_nbWorkers=400,    /* Select how many threads will be spawned to compress in parallel.
                              * When nbWorkers >= 1, triggers asynchronous mode when invoking ZSTD_compressStream*() :
                              * ZSTD_compressStream*() consumes input and flush output if possible, but immediately gives back control to caller,
                              * while compression is performed in parallel, within worker thread(s).
                              * (note : a strong exception to this rule is when first invocation of ZSTD_compressStream2() sets ZSTD_e_end :
                              *  in which case, ZSTD_compressStream2() delegates to ZSTD_compress2(), which is always a blocking call).
                              * More workers improve speed, but also increase memory usage.
                              * Default value is `0`, aka "single-threaded mode" : no worker is spawned,
                              * compression is performed inside Caller's thread, and all invocations are blocking */
    ZSTD_c_jobSize=401,      /* Size of a compression job. This value is enforced only when nbWorkers >= 1.
                              * Each compression job is completed in parallel, so this value can indirectly impact the nb of active threads.
                              * 0 means default, which is dynamically determined based on compression parameters.
                              * Job size must be a minimum of overlap size, or ZSTDMT_JOBSIZE_MIN (= 512 KB), whichever is largest.
                              * The minimum size is automatically and transparently enforced. */
    ZSTD_c_overlapLog=402,   /* Control the overlap size, as a fraction of window size.
                              * The overlap size is an amount of data reloaded from previous job at the beginning of a new job.
                              * It helps preserve compression ratio, while each job is compressed in parallel.
                              * This value is enforced only when nbWorkers >= 1.
                              * Larger values increase compression ratio, but decrease speed.
                              * Possible values range from 0 to 9 :
                              * - 0 means "default" : value will be determined by the library, depending on strategy
                              * - 1 means "no overlap"
                              * - 9 means "full overlap", using a full window size.
                              * Each intermediate rank increases/decreases load size by a factor 2 :
                              * 9: full window;  8: w/2;  7: w/4;  6: w/8;  5:w/16;  4: w/32;  3:w/64;  2:w/128;  1:no overlap;  0:default
                              * default value varies between 6 and 9, depending on strategy */

    /* note : additional experimental parameters are also available
     * within the experimental section of the API.
     * At the time of this writing, they include :
     * ZSTD_c_rsyncable
     * ZSTD_c_format
     * ZSTD_c_forceMaxWindow
     * ZSTD_c_forceAttachDict
     * ZSTD_c_literalCompressionMode
     * ZSTD_c_srcSizeHint
     * ZSTD_c_enableDedicatedDictSearch
     * ZSTD_c_stableInBuffer
     * ZSTD_c_stableOutBuffer
     * ZSTD_c_blockDelimiters
     * ZSTD_c_validateSequences
     * ZSTD_c_useBlockSplitter
     * ZSTD_c_useRowMatchFinder
     * ZSTD_c_prefetchCDictTables
     * ZSTD_c_enableSeqProducerFallback
     * ZSTD_c_maxBlockSize
     * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
     * note : never ever use experimentalParam? names directly;
     *        also, the enums values themselves are unstable and can still change.
     */
     ZSTD_c_experimentalParam1=500,
     ZSTD_c_experimentalParam2=10,
     ZSTD_c_experimentalParam3=1000,
     ZSTD_c_experimentalParam4=1001,
     ZSTD_c_experimentalParam5=1002,
     /* was ZSTD_c_experimentalParam6=1003; is now ZSTD_c_targetCBlockSize */
     ZSTD_c_experimentalParam7=1004,
     ZSTD_c_experimentalParam8=1005,
     ZSTD_c_experimentalParam9=1006,
     ZSTD_c_experimentalParam10=1007,
     ZSTD_c_experimentalParam11=1008,
     ZSTD_c_experimentalParam12=1009,
     ZSTD_c_experimentalParam13=1010,
     ZSTD_c_experimentalParam14=1011,
     ZSTD_c_experimentalParam15=1012,
     ZSTD_c_experimentalParam16=1013,
     ZSTD_c_experimentalParam17=1014,
     ZSTD_c_experimentalParam18=1015,
     ZSTD_c_experimentalParam19=1016
} ZSTD_cParameter;

typedef struct {
    size_t error;
    int lowerBound;
    int upperBound;
} ZSTD_bounds;

/*! ZSTD_cParam_getBounds() :
 *  All parameters must belong to an interval with lower and upper bounds,
 *  otherwise they will either trigger an error or be automatically clamped.
 * @return : a structure, ZSTD_bounds, which contains
 *         - an error status field, which must be tested using ZSTD_isError()
 *         - lower and upper bounds, both inclusive
 */
ZSTDLIB_API ZSTD_bounds ZSTD_cParam_getBounds(ZSTD_cParameter cParam);

/*! ZSTD_CCtx_setParameter() :
 *  Set one compression parameter, selected by enum ZSTD_cParameter.
 *  All parameters have valid bounds. Bounds can be queried using ZSTD_cParam_getBounds().
 *  Providing a value beyond bound will either clamp it, or trigger an error (depending on parameter).
 *  Setting a parameter is generally only possible during frame initialization (before starting compression).
 *  Exception : when using multi-threading mode (nbWorkers >= 1),
 *              the following parameters can be updated _during_ compression (within same frame):
 *              => compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
 *              new parameters will be active for next job only (after a flush()).
 * @return : an error code (which can be tested using ZSTD_isError()).
 */
ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, int value);

/*! ZSTD_CCtx_setPledgedSrcSize() :
 *  Total input data size to be compressed as a single frame.
 *  Value will be written in frame header, unless if explicitly forbidden using ZSTD_c_contentSizeFlag.
 *  This value will also be controlled at end of frame, and trigger an error if not respected.
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Note 1 : pledgedSrcSize==0 actually means zero, aka an empty frame.
 *           In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
 *           ZSTD_CONTENTSIZE_UNKNOWN is default value for any new frame.
 *  Note 2 : pledgedSrcSize is only valid once, for the next frame.
 *           It's discarded at the end of the frame, and replaced by ZSTD_CONTENTSIZE_UNKNOWN.
 *  Note 3 : Whenever all input data is provided and consumed in a single round,
 *           for example with ZSTD_compress2(),
 *           or invoking immediately ZSTD_compressStream2(,,,ZSTD_e_end),
 *           this value is automatically overridden by srcSize instead.
 */
ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);

typedef enum {
    ZSTD_reset_session_only = 1,
    ZSTD_reset_parameters = 2,
    ZSTD_reset_session_and_parameters = 3
} ZSTD_ResetDirective;

/*! ZSTD_CCtx_reset() :
 *  There are 2 different things that can be reset, independently or jointly :
 *  - The session : will stop compressing current frame, and make CCtx ready to start a new one.
 *                  Useful after an error, or to interrupt any ongoing compression.
 *                  Any internal data not yet flushed is cancelled.
 *                  Compression parameters and dictionary remain unchanged.
 *                  They will be used to compress next frame.
 *                  Resetting session never fails.
 *  - The parameters : changes all parameters back to "default".
 *                  This also removes any reference to any dictionary or external sequence producer.
 *                  Parameters can only be changed between 2 sessions (i.e. no compression is currently ongoing)
 *                  otherwise the reset fails, and function returns an error value (which can be tested using ZSTD_isError())
 *  - Both : similar to resetting the session, followed by resetting parameters.
 */
ZSTDLIB_API size_t ZSTD_CCtx_reset(ZSTD_CCtx* cctx, ZSTD_ResetDirective reset);

/*! ZSTD_compress2() :
 *  Behave the same as ZSTD_compressCCtx(), but compression parameters are set using the advanced API.
 *  (note that this entry point doesn't even expose a compression level parameter).
 *  ZSTD_compress2() always starts a new frame.
 *  Should cctx hold data from a previously unfinished frame, everything about it is forgotten.
 *  - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
 *  - The function is always blocking, returns when compression is completed.
 *  NOTE: Providing `dstCapacity >= ZSTD_compressBound(srcSize)` guarantees that zstd will have
 *        enough space to successfully compress the data, though it is possible it fails for other reasons.
 * @return : compressed size written into `dst` (<= `dstCapacity),
 *           or an error code if it fails (which can be tested using ZSTD_isError()).
 */
ZSTDLIB_API size_t ZSTD_compress2( ZSTD_CCtx* cctx,
                                   void* dst, size_t dstCapacity,
                             const void* src, size_t srcSize);


/***********************************************
*  Advanced decompression API (Requires v1.4.0+)
************************************************/

/* The advanced API pushes parameters one by one into an existing DCtx context.
 * Parameters are sticky, and remain valid for all following frames
 * using the same DCtx context.
 * It's possible to reset parameters to default values using ZSTD_DCtx_reset().
 * Note : This API is compatible with existing ZSTD_decompressDCtx() and ZSTD_decompressStream().
 *        Therefore, no new decompression function is necessary.
 */

typedef enum {

    ZSTD_d_windowLogMax=100, /* Select a size limit (in power of 2) beyond which
                              * the streaming API will refuse to allocate memory buffer
                              * in order to protect the host from unreasonable memory requirements.
                              * This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
                              * By default, a decompression context accepts window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT).
                              * Special: value 0 means "use default maximum windowLog". */

    /* note : additional experimental parameters are also available
     * within the experimental section of the API.
     * At the time of this writing, they include :
     * ZSTD_d_format
     * ZSTD_d_stableOutBuffer
     * ZSTD_d_forceIgnoreChecksum
     * ZSTD_d_refMultipleDDicts
     * ZSTD_d_disableHuffmanAssembly
     * ZSTD_d_maxBlockSize
     * Because they are not stable, it's necessary to define ZSTD_STATIC_LINKING_ONLY to access them.
     * note : never ever use experimentalParam? names directly
     */
     ZSTD_d_experimentalParam1=1000,
     ZSTD_d_experimentalParam2=1001,
     ZSTD_d_experimentalParam3=1002,
     ZSTD_d_experimentalParam4=1003,
     ZSTD_d_experimentalParam5=1004,
     ZSTD_d_experimentalParam6=1005

} ZSTD_dParameter;

/*! ZSTD_dParam_getBounds() :
 *  All parameters must belong to an interval with lower and upper bounds,
 *  otherwise they will either trigger an error or be automatically clamped.
 * @return : a structure, ZSTD_bounds, which contains
 *         - an error status field, which must be tested using ZSTD_isError()
 *         - both lower and upper bounds, inclusive
 */
ZSTDLIB_API ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam);

/*! ZSTD_DCtx_setParameter() :
 *  Set one compression parameter, selected by enum ZSTD_dParameter.
 *  All parameters have valid bounds. Bounds can be queried using ZSTD_dParam_getBounds().
 *  Providing a value beyond bound will either clamp it, or trigger an error (depending on parameter).
 *  Setting a parameter is only possible during frame initialization (before starting decompression).
 * @return : 0, or an error code (which can be tested using ZSTD_isError()).
 */
ZSTDLIB_API size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int value);

/*! ZSTD_DCtx_reset() :
 *  Return a DCtx to clean state.
 *  Session and parameters can be reset jointly or separately.
 *  Parameters can only be reset when no active frame is being decompressed.
 * @return : 0, or an error code, which can be tested with ZSTD_isError()
 */
ZSTDLIB_API size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset);


/****************************
*  Streaming
****************************/

typedef struct ZSTD_inBuffer_s {
  const void* src;    /**< start of input buffer */
  size_t size;        /**< size of input buffer */
  size_t pos;         /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
} ZSTD_inBuffer;

typedef struct ZSTD_outBuffer_s {
  void*  dst;         /**< start of output buffer */
  size_t size;        /**< size of output buffer */
  size_t pos;         /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
} ZSTD_outBuffer;



/*-***********************************************************************
*  Streaming compression - HowTo
*
*  A ZSTD_CStream object is required to track streaming operation.
*  Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources.
*  ZSTD_CStream objects can be reused multiple times on consecutive compression operations.
*  It is recommended to reuse ZSTD_CStream since it will play nicer with system's memory, by re-using already allocated memory.
*
*  For parallel execution, use one separate ZSTD_CStream per thread.
*
*  note : since v1.3.0, ZSTD_CStream and ZSTD_CCtx are the same thing.
*
*  Parameters are sticky : when starting a new compression on the same context,
*  it will reuse the same sticky parameters as previous compression session.
*  When in doubt, it's recommended to fully initialize the context before usage.
*  Use ZSTD_CCtx_reset() to reset the context and ZSTD_CCtx_setParameter(),
*  ZSTD_CCtx_setPledgedSrcSize(), or ZSTD_CCtx_loadDictionary() and friends to
*  set more specific parameters, the pledged source size, or load a dictionary.
*
*  Use ZSTD_compressStream2() with ZSTD_e_continue as many times as necessary to
*  consume input stream. The function will automatically update both `pos`
*  fields within `input` and `output`.
*  Note that the function may not consume the entire input, for example, because
*  the output buffer is already full, in which case `input.pos < input.size`.
*  The caller must check if input has been entirely consumed.
*  If not, the caller must make some room to receive more compressed data,
*  and then present again remaining input data.
*  note: ZSTD_e_continue is guaranteed to make some forward progress when called,
*        but doesn't guarantee maximal forward progress. This is especially relevant
*        when compressing with multiple threads. The call won't block if it can
*        consume some input, but if it can't it will wait for some, but not all,
*        output to be flushed.
* @return : provides a minimum amount of data remaining to be flushed from internal buffers
*           or an error code, which can be tested using ZSTD_isError().
*
*  At any moment, it's possible to flush whatever data might remain stuck within internal buffer,
*  using ZSTD_compressStream2() with ZSTD_e_flush. `output->pos` will be updated.
*  Note that, if `output->size` is too small, a single invocation with ZSTD_e_flush might not be enough (return code > 0).
*  In which case, make some room to receive more compressed data, and call again ZSTD_compressStream2() with ZSTD_e_flush.
*  You must continue calling ZSTD_compressStream2() with ZSTD_e_flush until it returns 0, at which point you can change the
*  operation.
*  note: ZSTD_e_flush will flush as much output as possible, meaning when compressing with multiple threads, it will
*        block until the flush is complete or the output buffer is full.
*  @return : 0 if internal buffers are entirely flushed,
*            >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
*            or an error code, which can be tested using ZSTD_isError().
*
*  Calling ZSTD_compressStream2() with ZSTD_e_end instructs to finish a frame.
*  It will perform a flush and write frame epilogue.
*  The epilogue is required for decoders to consider a frame completed.
*  flush operation is the same, and follows same rules as calling ZSTD_compressStream2() with ZSTD_e_flush.
*  You must continue calling ZSTD_compressStream2() with ZSTD_e_end until it returns 0, at which point you are free to
*  start a new frame.
*  note: ZSTD_e_end will flush as much output as possible, meaning when compressing with multiple threads, it will
*        block until the flush is complete or the output buffer is full.
*  @return : 0 if frame fully completed and fully flushed,
*            >0 if some data still present within internal buffer (the value is minimal estimation of remaining size),
*            or an error code, which can be tested using ZSTD_isError().
*
* *******************************************************************/

typedef ZSTD_CCtx ZSTD_CStream;  /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
                                 /* Continue to distinguish them for compatibility with older versions <= v1.2.0 */
/*===== ZSTD_CStream management functions =====*/
ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);  /* accept NULL pointer */

/*===== Streaming compression functions =====*/
typedef enum {
    ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal compression ratio */
    ZSTD_e_flush=1,    /* flush any data provided so far,
                        * it creates (at least) one new block, that can be decoded immediately on reception;
                        * frame will continue: any future data can still reference previously compressed data, improving compression.
                        * note : multithreaded compression will block to flush as much output as possible. */
    ZSTD_e_end=2       /* flush any remaining data _and_ close current frame.
                        * note that frame is only closed after compressed data is fully flushed (return value == 0).
                        * After that point, any additional data starts a new frame.
                        * note : each frame is independent (does not reference any content from previous frame).
                        : note : multithreaded compression will block to flush as much output as possible. */
} ZSTD_EndDirective;

/*! ZSTD_compressStream2() : Requires v1.4.0+
 *  Behaves about the same as ZSTD_compressStream, with additional control on end directive.
 *  - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_set*()
 *  - Compression parameters cannot be changed once compression is started (save a list of exceptions in multi-threading mode)
 *  - output->pos must be <= dstCapacity, input->pos must be <= srcSize
 *  - output->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
 *  - endOp must be a valid directive
 *  - When nbWorkers==0 (default), function is blocking : it completes its job before returning to caller.
 *  - When nbWorkers>=1, function is non-blocking : it copies a portion of input, distributes jobs to internal worker threads, flush to output whatever is available,
 *                                                  and then immediately returns, just indicating that there is some data remaining to be flushed.
 *                                                  The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
 *  - Exception : if the first call requests a ZSTD_e_end directive and provides enough dstCapacity, the function delegates to ZSTD_compress2() which is always blocking.
 *  - @return provides a minimum amount of data remaining to be flushed from internal buffers
 *            or an error code, which can be tested using ZSTD_isError().
 *            if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
 *            This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
 *            For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
 *  - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
 *            only ZSTD_e_end or ZSTD_e_flush operations are allowed.
 *            Before starting a new compression job, or changing compression parameters,
 *            it is required to fully flush internal buffers.
 *  - note: if an operation ends with an error, it may leave @cctx in an undefined state.
 *          Therefore, it's UB to invoke ZSTD_compressStream2() of ZSTD_compressStream() on such a state.
 *          In order to be re-employed after an error, a state must be reset,
 *          which can be done explicitly (ZSTD_CCtx_reset()),
 *          or is sometimes implied by methods starting a new compression job (ZSTD_initCStream(), ZSTD_compressCCtx())
 */
ZSTDLIB_API size_t ZSTD_compressStream2( ZSTD_CCtx* cctx,
                                         ZSTD_outBuffer* output,
                                         ZSTD_inBuffer* input,
                                         ZSTD_EndDirective endOp);


/* These buffer sizes are softly recommended.
 * They are not required : ZSTD_compressStream*() happily accepts any buffer size, for both input and output.
 * Respecting the recommended size just makes it a bit easier for ZSTD_compressStream*(),
 * reducing the amount of memory shuffling and buffering, resulting in minor performance savings.
 *
 * However, note that these recommendations are from the perspective of a C caller program.
 * If the streaming interface is invoked from some other language,
 * especially managed ones such as Java or Go, through a foreign function interface such as jni or cgo,
 * a major performance rule is to reduce crossing such interface to an absolute minimum.
 * It's not rare that performance ends being spent more into the interface, rather than compression itself.
 * In which cases, prefer using large buffers, as large as practical,
 * for both input and output, to reduce the nb of roundtrips.
 */
ZSTDLIB_API size_t ZSTD_CStreamInSize(void);    /**< recommended size for input buffer */
ZSTDLIB_API size_t ZSTD_CStreamOutSize(void);   /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block. */


/* *****************************************************************************
 * This following is a legacy streaming API, available since v1.0+ .
 * It can be replaced by ZSTD_CCtx_reset() and ZSTD_compressStream2().
 * It is redundant, but remains fully supported.
 ******************************************************************************/

/*!
 * Equivalent to:
 *
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
 *     ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
 *
 * Note that ZSTD_initCStream() clears any previously set dictionary. Use the new API
 * to compress with a dictionary.
 */
ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
/*!
 * Alternative for ZSTD_compressStream2(zcs, output, input, ZSTD_e_continue).
 * NOTE: The return value is different. ZSTD_compressStream() returns a hint for
 * the next read size (if non-zero and not an error). ZSTD_compressStream2()
 * returns the minimum nb of bytes left to flush (if non-zero and not an error).
 */
ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
/*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_flush). */
ZSTDLIB_API size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
/*! Equivalent to ZSTD_compressStream2(zcs, output, &emptyInput, ZSTD_e_end). */
ZSTDLIB_API size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);


/*-***************************************************************************
*  Streaming decompression - HowTo
*
*  A ZSTD_DStream object is required to track streaming operations.
*  Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources.
*  ZSTD_DStream objects can be reused multiple times.
*
*  Use ZSTD_initDStream() to start a new decompression operation.
* @return : recommended first input size
*  Alternatively, use advanced API to set specific properties.
*
*  Use ZSTD_decompressStream() repetitively to consume your input.
*  The function will update both `pos` fields.
*  If `input.pos < input.size`, some input has not been consumed.
*  It's up to the caller to present again remaining data.
*  The function tries to flush all data decoded immediately, respecting output buffer size.
*  If `output.pos < output.size`, decoder has flushed everything it could.
*  But if `output.pos == output.size`, there might be some data left within internal buffers.,
*  In which case, call ZSTD_decompressStream() again to flush whatever remains in the buffer.
*  Note : with no additional input provided, amount of data flushed is necessarily <= ZSTD_BLOCKSIZE_MAX.
* @return : 0 when a frame is completely decoded and fully flushed,
*        or an error code, which can be tested using ZSTD_isError(),
*        or any other value > 0, which means there is still some decoding or flushing to do to complete current frame :
*                                the return value is a suggested next input size (just a hint for better latency)
*                                that will never request more than the remaining frame size.
* *******************************************************************************/

typedef ZSTD_DCtx ZSTD_DStream;  /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
                                 /* For compatibility with versions <= v1.2.0, prefer differentiating them. */
/*===== ZSTD_DStream management functions =====*/
ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);  /* accept NULL pointer */

/*===== Streaming decompression functions =====*/

/*! ZSTD_initDStream() :
 * Initialize/reset DStream state for new decompression operation.
 * Call before new decompression operation using same DStream.
 *
 * Note : This function is redundant with the advanced API and equivalent to:
 *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
 *     ZSTD_DCtx_refDDict(zds, NULL);
 */
ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);

/*! ZSTD_decompressStream() :
 * Streaming decompression function.
 * Call repetitively to consume full input updating it as necessary.
 * Function will update both input and output `pos` fields exposing current state via these fields:
 * - `input.pos < input.size`, some input remaining and caller should provide remaining input
 *   on the next call.
 * - `output.pos < output.size`, decoder finished and flushed all remaining buffers.
 * - `output.pos == output.size`, potentially uncflushed data present in the internal buffers,
 *   call ZSTD_decompressStream() again to flush remaining data to output.
 * Note : with no additional input, amount of data flushed <= ZSTD_BLOCKSIZE_MAX.
 *
 * @return : 0 when a frame is completely decoded and fully flushed,
 *           or an error code, which can be tested using ZSTD_isError(),
 *           or any other value > 0, which means there is some decoding or flushing to do to complete current frame.
 *
 * Note: when an operation returns with an error code, the @zds state may be left in undefined state.
 *       It's UB to invoke `ZSTD_decompressStream()` on such a state.
 *       In order to re-use such a state, it must be first reset,
 *       which can be done explicitly (`ZSTD_DCtx_reset()`),
 *       or is implied for operations starting some new decompression job (`ZSTD_initDStream`, `ZSTD_decompressDCtx()`, `ZSTD_decompress_usingDict()`)
 */
ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);

ZSTDLIB_API size_t ZSTD_DStreamInSize(void);    /*!< recommended size for input buffer */
ZSTDLIB_API size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */


/**************************
*  Simple dictionary API
***************************/
/*! ZSTD_compress_usingDict() :
 *  Compression at an explicit compression level using a Dictionary.
 *  A dictionary can be any arbitrary data segment (also called a prefix),
 *  or a buffer with specified information (see zdict.h).
 *  Note : This function loads the dictionary, resulting in significant startup delay.
 *         It's intended for a dictionary used only once.
 *  Note 2 : When `dict == NULL || dictSize < 8` no dictionary is used. */
ZSTDLIB_API size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
                                           void* dst, size_t dstCapacity,
                                     const void* src, size_t srcSize,
                                     const void* dict,size_t dictSize,
                                           int compressionLevel);

/*! ZSTD_decompress_usingDict() :
 *  Decompression using a known Dictionary.
 *  Dictionary must be identical to the one used during compression.
 *  Note : This function loads the dictionary, resulting in significant startup delay.
 *         It's intended for a dictionary used only once.
 *  Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
ZSTDLIB_API size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
                                             void* dst, size_t dstCapacity,
                                       const void* src, size_t srcSize,
                                       const void* dict,size_t dictSize);


/***********************************
 *  Bulk processing dictionary API
 **********************************/
typedef struct ZSTD_CDict_s ZSTD_CDict;

/*! ZSTD_createCDict() :
 *  When compressing multiple messages or blocks using the same dictionary,
 *  it's recommended to digest the dictionary only once, since it's a costly operation.
 *  ZSTD_createCDict() will create a state from digesting a dictionary.
 *  The resulting state can be used for future compression operations with very limited startup cost.
 *  ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
 * @dictBuffer can be released after ZSTD_CDict creation, because its content is copied within CDict.
 *  Note 1 : Consider experimental function `ZSTD_createCDict_byReference()` if you prefer to not duplicate @dictBuffer content.
 *  Note 2 : A ZSTD_CDict can be created from an empty @dictBuffer,
 *      in which case the only thing that it transports is the @compressionLevel.
 *      This can be useful in a pipeline featuring ZSTD_compress_usingCDict() exclusively,
 *      expecting a ZSTD_CDict parameter with any data, including those without a known dictionary. */
ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
                                         int compressionLevel);

/*! ZSTD_freeCDict() :
 *  Function frees memory allocated by ZSTD_createCDict().
 *  If a NULL pointer is passed, no operation is performed. */
ZSTDLIB_API size_t      ZSTD_freeCDict(ZSTD_CDict* CDict);

/*! ZSTD_compress_usingCDict() :
 *  Compression using a digested Dictionary.
 *  Recommended when same dictionary is used multiple times.
 *  Note : compression level is _decided at dictionary creation time_,
 *     and frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) */
ZSTDLIB_API size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
                                            void* dst, size_t dstCapacity,
                                      const void* src, size_t srcSize,
                                      const ZSTD_CDict* cdict);


typedef struct ZSTD_DDict_s ZSTD_DDict;

/*! ZSTD_createDDict() :
 *  Create a digested dictionary, ready to start decompression operation without startup delay.
 *  dictBuffer can be released after DDict creation, as its content is copied inside DDict. */
ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);

/*! ZSTD_freeDDict() :
 *  Function frees memory allocated with ZSTD_createDDict()
 *  If a NULL pointer is passed, no operation is performed. */
ZSTDLIB_API size_t      ZSTD_freeDDict(ZSTD_DDict* ddict);

/*! ZSTD_decompress_usingDDict() :
 *  Decompression using a digested Dictionary.
 *  Recommended when same dictionary is used multiple times. */
ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
                                              void* dst, size_t dstCapacity,
                                        const void* src, size_t srcSize,
                                        const ZSTD_DDict* ddict);


/********************************
 *  Dictionary helper functions
 *******************************/

/*! ZSTD_getDictID_fromDict() : Requires v1.4.0+
 *  Provides the dictID stored within dictionary.
 *  if @return == 0, the dictionary is not conformant with Zstandard specification.
 *  It can still be loaded, but as a content-only dictionary. */
ZSTDLIB_API unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);

/*! ZSTD_getDictID_fromCDict() : Requires v1.5.0+
 *  Provides the dictID of the dictionary loaded into `cdict`.
 *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
 *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
ZSTDLIB_API unsigned ZSTD_getDictID_fromCDict(const ZSTD_CDict* cdict);

/*! ZSTD_getDictID_fromDDict() : Requires v1.4.0+
 *  Provides the dictID of the dictionary loaded into `ddict`.
 *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
 *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
ZSTDLIB_API unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);

/*! ZSTD_getDictID_fromFrame() : Requires v1.4.0+
 *  Provides the dictID required to decompressed the frame stored within `src`.
 *  If @return == 0, the dictID could not be decoded.
 *  This could for one of the following reasons :
 *  - The frame does not require a dictionary to be decoded (most common case).
 *  - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden piece of information.
 *    Note : this use case also happens when using a non-conformant dictionary.
 *  - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
 *  - This is not a Zstandard frame.
 *  When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. */
ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);


/*******************************************************************************
 * Advanced dictionary and prefix API (Requires v1.4.0+)
 *
 * This API allows dictionaries to be used with ZSTD_compress2(),
 * ZSTD_compressStream2(), and ZSTD_decompressDCtx().
 * Dictionaries are sticky, they remain valid when same context is reused,
 * they only reset when the context is reset
 * with ZSTD_reset_parameters or ZSTD_reset_session_and_parameters.
 * In contrast, Prefixes are single-use.
 ******************************************************************************/


/*! ZSTD_CCtx_loadDictionary() : Requires v1.4.0+
 *  Create an internal CDict from `dict` buffer.
 *  Decompression will have to use same dictionary.
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Special: Loading a NULL (or 0-size) dictionary invalidates previous dictionary,
 *           meaning "return to no-dictionary mode".
 *  Note 1 : Dictionary is sticky, it will be used for all future compressed frames,
 *           until parameters are reset, a new dictionary is loaded, or the dictionary
 *           is explicitly invalidated by loading a NULL dictionary.
 *  Note 2 : Loading a dictionary involves building tables.
 *           It's also a CPU consuming operation, with non-negligible impact on latency.
 *           Tables are dependent on compression parameters, and for this reason,
 *           compression parameters can no longer be changed after loading a dictionary.
 *  Note 3 :`dict` content will be copied internally.
 *           Use experimental ZSTD_CCtx_loadDictionary_byReference() to reference content instead.
 *           In such a case, dictionary buffer must outlive its users.
 *  Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
 *           to precisely select how dictionary content must be interpreted.
 *  Note 5 : This method does not benefit from LDM (long distance mode).
 *           If you want to employ LDM on some large dictionary content,
 *           prefer employing ZSTD_CCtx_refPrefix() described below.
 */
ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);

/*! ZSTD_CCtx_refCDict() : Requires v1.4.0+
 *  Reference a prepared dictionary, to be used for all future compressed frames.
 *  Note that compression parameters are enforced from within CDict,
 *  and supersede any compression parameter previously set within CCtx.
 *  The parameters ignored are labelled as "superseded-by-cdict" in the ZSTD_cParameter enum docs.
 *  The ignored parameters will be used again if the CCtx is returned to no-dictionary mode.
 *  The dictionary will remain valid for future compressed frames using same CCtx.
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Special : Referencing a NULL CDict means "return to no-dictionary mode".
 *  Note 1 : Currently, only one dictionary can be managed.
 *           Referencing a new dictionary effectively "discards" any previous one.
 *  Note 2 : CDict is just referenced, its lifetime must outlive its usage within CCtx. */
ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);

/*! ZSTD_CCtx_refPrefix() : Requires v1.4.0+
 *  Reference a prefix (single-usage dictionary) for next compressed frame.
 *  A prefix is **only used once**. Tables are discarded at end of frame (ZSTD_e_end).
 *  Decompression will need same prefix to properly regenerate data.
 *  Compressing with a prefix is similar in outcome as performing a diff and compressing it,
 *  but performs much faster, especially during decompression (compression speed is tunable with compression level).
 *  This method is compatible with LDM (long distance mode).
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
 *  Note 1 : Prefix buffer is referenced. It **must** outlive compression.
 *           Its content must remain unmodified during compression.
 *  Note 2 : If the intention is to diff some large src data blob with some prior version of itself,
 *           ensure that the window size is large enough to contain the entire source.
 *           See ZSTD_c_windowLog.
 *  Note 3 : Referencing a prefix involves building tables, which are dependent on compression parameters.
 *           It's a CPU consuming operation, with non-negligible impact on latency.
 *           If there is a need to use the same prefix multiple times, consider loadDictionary instead.
 *  Note 4 : By default, the prefix is interpreted as raw content (ZSTD_dct_rawContent).
 *           Use experimental ZSTD_CCtx_refPrefix_advanced() to alter dictionary interpretation. */
ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx,
                                 const void* prefix, size_t prefixSize);

/*! ZSTD_DCtx_loadDictionary() : Requires v1.4.0+
 *  Create an internal DDict from dict buffer, to be used to decompress all future frames.
 *  The dictionary remains valid for all future frames, until explicitly invalidated, or
 *  a new dictionary is loaded.
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Special : Adding a NULL (or 0-size) dictionary invalidates any previous dictionary,
 *            meaning "return to no-dictionary mode".
 *  Note 1 : Loading a dictionary involves building tables,
 *           which has a non-negligible impact on CPU usage and latency.
 *           It's recommended to "load once, use many times", to amortize the cost
 *  Note 2 :`dict` content will be copied internally, so `dict` can be released after loading.
 *           Use ZSTD_DCtx_loadDictionary_byReference() to reference dictionary content instead.
 *  Note 3 : Use ZSTD_DCtx_loadDictionary_advanced() to take control of
 *           how dictionary content is loaded and interpreted.
 */
ZSTDLIB_API size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);

/*! ZSTD_DCtx_refDDict() : Requires v1.4.0+
 *  Reference a prepared dictionary, to be used to decompress next frames.
 *  The dictionary remains active for decompression of future frames using same DCtx.
 *
 *  If called with ZSTD_d_refMultipleDDicts enabled, repeated calls of this function
 *  will store the DDict references in a table, and the DDict used for decompression
 *  will be determined at decompression time, as per the dict ID in the frame.
 *  The memory for the table is allocated on the first call to refDDict, and can be
 *  freed with ZSTD_freeDCtx().
 *
 *  If called with ZSTD_d_refMultipleDDicts disabled (the default), only one dictionary
 *  will be managed, and referencing a dictionary effectively "discards" any previous one.
 *
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Special: referencing a NULL DDict means "return to no-dictionary mode".
 *  Note 2 : DDict is just referenced, its lifetime must outlive its usage from DCtx.
 */
ZSTDLIB_API size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);

/*! ZSTD_DCtx_refPrefix() : Requires v1.4.0+
 *  Reference a prefix (single-usage dictionary) to decompress next frame.
 *  This is the reverse operation of ZSTD_CCtx_refPrefix(),
 *  and must use the same prefix as the one used during compression.
 *  Prefix is **only used once**. Reference is discarded at end of frame.
 *  End of frame is reached when ZSTD_decompressStream() returns 0.
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 *  Note 1 : Adding any prefix (including NULL) invalidates any previously set prefix or dictionary
 *  Note 2 : Prefix buffer is referenced. It **must** outlive decompression.
 *           Prefix buffer must remain unmodified up to the end of frame,
 *           reached when ZSTD_decompressStream() returns 0.
 *  Note 3 : By default, the prefix is treated as raw content (ZSTD_dct_rawContent).
 *           Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode (Experimental section)
 *  Note 4 : Referencing a raw content prefix has almost no cpu nor memory cost.
 *           A full dictionary is more costly, as it requires building tables.
 */
ZSTDLIB_API size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx,
                                 const void* prefix, size_t prefixSize);

/* ===   Memory management   === */

/*! ZSTD_sizeof_*() : Requires v1.4.0+
 *  These functions give the _current_ memory usage of selected object.
 *  Note that object memory usage can evolve (increase or decrease) over time. */
ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
ZSTDLIB_API size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);

#endif  /* ZSTD_H_235446 */


/* **************************************************************************************
 *   ADVANCED AND EXPERIMENTAL FUNCTIONS
 ****************************************************************************************
 * The definitions in the following section are considered experimental.
 * They are provided for advanced scenarios.
 * They should never be used with a dynamic library, as prototypes may change in the future.
 * Use them only in association with static linking.
 * ***************************************************************************************/

#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY

/* This can be overridden externally to hide static symbols. */
#ifndef ZSTDLIB_STATIC_API
#  if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
#    define ZSTDLIB_STATIC_API __declspec(dllexport) ZSTDLIB_VISIBLE
#  elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
#    define ZSTDLIB_STATIC_API __declspec(dllimport) ZSTDLIB_VISIBLE
#  else
#    define ZSTDLIB_STATIC_API ZSTDLIB_VISIBLE
#  endif
#endif

/****************************************************************************************
 *   experimental API (static linking only)
 ****************************************************************************************
 * The following symbols and constants
 * are not planned to join "stable API" status in the near future.
 * They can still change in future versions.
 * Some of them are planned to remain in the static_only section indefinitely.
 * Some of them might be removed in the future (especially when redundant with existing stable functions)
 * ***************************************************************************************/

#define ZSTD_FRAMEHEADERSIZE_PREFIX(format) ((format) == ZSTD_f_zstd1 ? 5 : 1)   /* minimum input size required to query frame header size */
#define ZSTD_FRAMEHEADERSIZE_MIN(format)    ((format) == ZSTD_f_zstd1 ? 6 : 2)
#define ZSTD_FRAMEHEADERSIZE_MAX   18   /* can be useful for static allocation */
#define ZSTD_SKIPPABLEHEADERSIZE    8

/* compression parameter bounds */
#define ZSTD_WINDOWLOG_MAX_32    30
#define ZSTD_WINDOWLOG_MAX_64    31
#define ZSTD_WINDOWLOG_MAX     ((int)(sizeof(size_t) == 4 ? ZSTD_WINDOWLOG_MAX_32 : ZSTD_WINDOWLOG_MAX_64))
#define ZSTD_WINDOWLOG_MIN       10
#define ZSTD_HASHLOG_MAX       ((ZSTD_WINDOWLOG_MAX < 30) ? ZSTD_WINDOWLOG_MAX : 30)
#define ZSTD_HASHLOG_MIN          6
#define ZSTD_CHAINLOG_MAX_32     29
#define ZSTD_CHAINLOG_MAX_64     30
#define ZSTD_CHAINLOG_MAX      ((int)(sizeof(size_t) == 4 ? ZSTD_CHAINLOG_MAX_32 : ZSTD_CHAINLOG_MAX_64))
#define ZSTD_CHAINLOG_MIN        ZSTD_HASHLOG_MIN
#define ZSTD_SEARCHLOG_MAX      (ZSTD_WINDOWLOG_MAX-1)
#define ZSTD_SEARCHLOG_MIN        1
#define ZSTD_MINMATCH_MAX         7   /* only for ZSTD_fast, other strategies are limited to 6 */
#define ZSTD_MINMATCH_MIN         3   /* only for ZSTD_btopt+, faster strategies are limited to 4 */
#define ZSTD_TARGETLENGTH_MAX    ZSTD_BLOCKSIZE_MAX
#define ZSTD_TARGETLENGTH_MIN     0   /* note : comparing this constant to an unsigned results in a tautological test */
#define ZSTD_STRATEGY_MIN        ZSTD_fast
#define ZSTD_STRATEGY_MAX        ZSTD_btultra2
#define ZSTD_BLOCKSIZE_MAX_MIN (1 << 10) /* The minimum valid max blocksize. Maximum blocksizes smaller than this make compressBound() inaccurate. */


#define ZSTD_OVERLAPLOG_MIN       0
#define ZSTD_OVERLAPLOG_MAX       9

#define ZSTD_WINDOWLOG_LIMIT_DEFAULT 27   /* by default, the streaming decoder will refuse any frame
                                           * requiring larger than (1<<ZSTD_WINDOWLOG_LIMIT_DEFAULT) window size,
                                           * to preserve host's memory from unreasonable requirements.
                                           * This limit can be overridden using ZSTD_DCtx_setParameter(,ZSTD_d_windowLogMax,).
                                           * The limit does not apply for one-pass decoders (such as ZSTD_decompress()), since no additional memory is allocated */


/* LDM parameter bounds */
#define ZSTD_LDM_HASHLOG_MIN      ZSTD_HASHLOG_MIN
#define ZSTD_LDM_HASHLOG_MAX      ZSTD_HASHLOG_MAX
#define ZSTD_LDM_MINMATCH_MIN        4
#define ZSTD_LDM_MINMATCH_MAX     4096
#define ZSTD_LDM_BUCKETSIZELOG_MIN   1
#define ZSTD_LDM_BUCKETSIZELOG_MAX   8
#define ZSTD_LDM_HASHRATELOG_MIN     0
#define ZSTD_LDM_HASHRATELOG_MAX (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN)

/* Advanced parameter bounds */
#define ZSTD_TARGETCBLOCKSIZE_MIN   1340 /* suitable to fit into an ethernet / wifi / 4G transport frame */
#define ZSTD_TARGETCBLOCKSIZE_MAX   ZSTD_BLOCKSIZE_MAX
#define ZSTD_SRCSIZEHINT_MIN        0
#define ZSTD_SRCSIZEHINT_MAX        INT_MAX


/* ---  Advanced types  --- */

typedef struct ZSTD_CCtx_params_s ZSTD_CCtx_params;

typedef struct {
    unsigned int offset;      /* The offset of the match. (NOT the same as the offset code)
                               * If offset == 0 and matchLength == 0, this sequence represents the last
                               * literals in the block of litLength size.
                               */

    unsigned int litLength;   /* Literal length of the sequence. */
    unsigned int matchLength; /* Match length of the sequence. */

                              /* Note: Users of this API may provide a sequence with matchLength == litLength == offset == 0.
                               * In this case, we will treat the sequence as a marker for a block boundary.
                               */

    unsigned int rep;         /* Represents which repeat offset is represented by the field 'offset'.
                               * Ranges from [0, 3].
                               *
                               * Repeat offsets are essentially previous offsets from previous sequences sorted in
                               * recency order. For more detail, see doc/zstd_compression_format.md
                               *
                               * If rep == 0, then 'offset' does not contain a repeat offset.
                               * If rep > 0:
                               *  If litLength != 0:
                               *      rep == 1 --> offset == repeat_offset_1
                               *      rep == 2 --> offset == repeat_offset_2
                               *      rep == 3 --> offset == repeat_offset_3
                               *  If litLength == 0:
                               *      rep == 1 --> offset == repeat_offset_2
                               *      rep == 2 --> offset == repeat_offset_3
                               *      rep == 3 --> offset == repeat_offset_1 - 1
                               *
                               * Note: This field is optional. ZSTD_generateSequences() will calculate the value of
                               * 'rep', but repeat offsets do not necessarily need to be calculated from an external
                               * sequence provider's perspective. For example, ZSTD_compressSequences() does not
                               * use this 'rep' field at all (as of now).
                               */
} ZSTD_Sequence;

typedef struct {
    unsigned windowLog;       /**< largest match distance : larger == more compression, more memory needed during decompression */
    unsigned chainLog;        /**< fully searched segment : larger == more compression, slower, more memory (useless for fast) */
    unsigned hashLog;         /**< dispatch table : larger == faster, more memory */
    unsigned searchLog;       /**< nb of searches : larger == more compression, slower */
    unsigned minMatch;        /**< match length searched : larger == faster decompression, sometimes less compression */
    unsigned targetLength;    /**< acceptable match size for optimal parser (only) : larger == more compression, slower */
    ZSTD_strategy strategy;   /**< see ZSTD_strategy definition above */
} ZSTD_compressionParameters;

typedef struct {
    int contentSizeFlag; /**< 1: content size will be in frame header (when known) */
    int checksumFlag;    /**< 1: generate a 32-bits checksum using XXH64 algorithm at end of frame, for error detection */
    int noDictIDFlag;    /**< 1: no dictID will be saved into frame header (dictID is only useful for dictionary compression) */
} ZSTD_frameParameters;

typedef struct {
    ZSTD_compressionParameters cParams;
    ZSTD_frameParameters fParams;
} ZSTD_parameters;

typedef enum {
    ZSTD_dct_auto = 0,       /* dictionary is "full" when starting with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */
    ZSTD_dct_rawContent = 1, /* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */
    ZSTD_dct_fullDict = 2    /* refuses to load a dictionary if it does not respect Zstandard's specification, starting with ZSTD_MAGIC_DICTIONARY */
} ZSTD_dictContentType_e;

typedef enum {
    ZSTD_dlm_byCopy = 0,  /**< Copy dictionary content internally */
    ZSTD_dlm_byRef = 1    /**< Reference dictionary content -- the dictionary buffer must outlive its users. */
} ZSTD_dictLoadMethod_e;

typedef enum {
    ZSTD_f_zstd1 = 0,           /* zstd frame format, specified in zstd_compression_format.md (default) */
    ZSTD_f_zstd1_magicless = 1  /* Variant of zstd frame format, without initial 4-bytes magic number.
                                 * Useful to save 4 bytes per generated frame.
                                 * Decoder cannot recognise automatically this format, requiring this instruction. */
} ZSTD_format_e;

typedef enum {
    /* Note: this enum controls ZSTD_d_forceIgnoreChecksum */
    ZSTD_d_validateChecksum = 0,
    ZSTD_d_ignoreChecksum = 1
} ZSTD_forceIgnoreChecksum_e;

typedef enum {
    /* Note: this enum controls ZSTD_d_refMultipleDDicts */
    ZSTD_rmd_refSingleDDict = 0,
    ZSTD_rmd_refMultipleDDicts = 1
} ZSTD_refMultipleDDicts_e;

typedef enum {
    /* Note: this enum and the behavior it controls are effectively internal
     * implementation details of the compressor. They are expected to continue
     * to evolve and should be considered only in the context of extremely
     * advanced performance tuning.
     *
     * Zstd currently supports the use of a CDict in three ways:
     *
     * - The contents of the CDict can be copied into the working context. This
     *   means that the compression can search both the dictionary and input
     *   while operating on a single set of internal tables. This makes
     *   the compression faster per-byte of input. However, the initial copy of
     *   the CDict's tables incurs a fixed cost at the beginning of the
     *   compression. For small compressions (< 8 KB), that copy can dominate
     *   the cost of the compression.
     *
     * - The CDict's tables can be used in-place. In this model, compression is
     *   slower per input byte, because the compressor has to search two sets of
     *   tables. However, this model incurs no start-up cost (as long as the
     *   working context's tables can be reused). For small inputs, this can be
     *   faster than copying the CDict's tables.
     *
     * - The CDict's tables are not used at all, and instead we use the working
     *   context alone to reload the dictionary and use params based on the source
     *   size. See ZSTD_compress_insertDictionary() and ZSTD_compress_usingDict().
     *   This method is effective when the dictionary sizes are very small relative
     *   to the input size, and the input size is fairly large to begin with.
     *
     * Zstd has a simple internal heuristic that selects which strategy to use
     * at the beginning of a compression. However, if experimentation shows that
     * Zstd is making poor choices, it is possible to override that choice with
     * this enum.
     */
    ZSTD_dictDefaultAttach = 0, /* Use the default heuristic. */
    ZSTD_dictForceAttach   = 1, /* Never copy the dictionary. */
    ZSTD_dictForceCopy     = 2, /* Always copy the dictionary. */
    ZSTD_dictForceLoad     = 3  /* Always reload the dictionary */
} ZSTD_dictAttachPref_e;

typedef enum {
  ZSTD_lcm_auto = 0,          /**< Automatically determine the compression mode based on the compression level.
                               *   Negative compression levels will be uncompressed, and positive compression
                               *   levels will be compressed. */
  ZSTD_lcm_huffman = 1,       /**< Always attempt Huffman compression. Uncompressed literals will still be
                               *   emitted if Huffman compression is not profitable. */
  ZSTD_lcm_uncompressed = 2   /**< Always emit uncompressed literals. */
} ZSTD_literalCompressionMode_e;

typedef enum {
  /* Note: This enum controls features which are conditionally beneficial. Zstd typically will make a final
   * decision on whether or not to enable the feature (ZSTD_ps_auto), but setting the switch to ZSTD_ps_enable
   * or ZSTD_ps_disable allow for a force enable/disable the feature.
   */
  ZSTD_ps_auto = 0,         /* Let the library automatically determine whether the feature shall be enabled */
  ZSTD_ps_enable = 1,       /* Force-enable the feature */
  ZSTD_ps_disable = 2       /* Do not use the feature */
} ZSTD_paramSwitch_e;

/***************************************
*  Frame header and size functions
***************************************/

/*! ZSTD_findDecompressedSize() :
 *  `src` should point to the start of a series of ZSTD encoded and/or skippable frames
 *  `srcSize` must be the _exact_ size of this series
 *       (i.e. there should be a frame boundary at `src + srcSize`)
 *  @return : - decompressed size of all data in all successive frames
 *            - if the decompressed size cannot be determined: ZSTD_CONTENTSIZE_UNKNOWN
 *            - if an error occurred: ZSTD_CONTENTSIZE_ERROR
 *
 *   note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
 *            When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
 *            In which case, it's necessary to use streaming mode to decompress data.
 *   note 2 : decompressed size is always present when compression is done with ZSTD_compress()
 *   note 3 : decompressed size can be very large (64-bits value),
 *            potentially larger than what local system can handle as a single memory segment.
 *            In which case, it's necessary to use streaming mode to decompress data.
 *   note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
 *            Always ensure result fits within application's authorized limits.
 *            Each application can set its own limits.
 *   note 5 : ZSTD_findDecompressedSize handles multiple frames, and so it must traverse the input to
 *            read each contained frame header.  This is fast as most of the data is skipped,
 *            however it does mean that all frame data must be present and valid. */
ZSTDLIB_STATIC_API unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);

/*! ZSTD_decompressBound() :
 *  `src` should point to the start of a series of ZSTD encoded and/or skippable frames
 *  `srcSize` must be the _exact_ size of this series
 *       (i.e. there should be a frame boundary at `src + srcSize`)
 *  @return : - upper-bound for the decompressed size of all data in all successive frames
 *            - if an error occurred: ZSTD_CONTENTSIZE_ERROR
 *
 *  note 1  : an error can occur if `src` contains an invalid or incorrectly formatted frame.
 *  note 2  : the upper-bound is exact when the decompressed size field is available in every ZSTD encoded frame of `src`.
 *            in this case, `ZSTD_findDecompressedSize` and `ZSTD_decompressBound` return the same value.
 *  note 3  : when the decompressed size field isn't available, the upper-bound for that frame is calculated by:
 *              upper-bound = # blocks * min(128 KB, Window_Size)
 */
ZSTDLIB_STATIC_API unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize);

/*! ZSTD_frameHeaderSize() :
 *  srcSize must be >= ZSTD_FRAMEHEADERSIZE_PREFIX.
 * @return : size of the Frame Header,
 *           or an error code (if srcSize is too small) */
ZSTDLIB_STATIC_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);

typedef enum { ZSTD_frame, ZSTD_skippableFrame } ZSTD_frameType_e;
typedef struct {
    unsigned long long frameContentSize; /* if == ZSTD_CONTENTSIZE_UNKNOWN, it means this field is not available. 0 means "empty" */
    unsigned long long windowSize;       /* can be very large, up to <= frameContentSize */
    unsigned blockSizeMax;
    ZSTD_frameType_e frameType;          /* if == ZSTD_skippableFrame, frameContentSize is the size of skippable content */
    unsigned headerSize;
    unsigned dictID;
    unsigned checksumFlag;
    unsigned _reserved1;
    unsigned _reserved2;
} ZSTD_frameHeader;

/*! ZSTD_getFrameHeader() :
 *  decode Frame Header, or requires larger `srcSize`.
 * @return : 0, `zfhPtr` is correctly filled,
 *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
 *           or an error code, which can be tested using ZSTD_isError() */
ZSTDLIB_STATIC_API size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize);   /**< doesn't consume input */
/*! ZSTD_getFrameHeader_advanced() :
 *  same as ZSTD_getFrameHeader(),
 *  with added capability to select a format (like ZSTD_f_zstd1_magicless) */
ZSTDLIB_STATIC_API size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format);

/*! ZSTD_decompressionMargin() :
 * Zstd supports in-place decompression, where the input and output buffers overlap.
 * In this case, the output buffer must be at least (Margin + Output_Size) bytes large,
 * and the input buffer must be at the end of the output buffer.
 *
 *  _______________________ Output Buffer ________________________
 * |                                                              |
 * |                                        ____ Input Buffer ____|
 * |                                       |                      |
 * v                                       v                      v
 * |---------------------------------------|-----------|----------|
 * ^                                                   ^          ^
 * |___________________ Output_Size ___________________|_ Margin _|
 *
 * NOTE: See also ZSTD_DECOMPRESSION_MARGIN().
 * NOTE: This applies only to single-pass decompression through ZSTD_decompress() or
 * ZSTD_decompressDCtx().
 * NOTE: This function supports multi-frame input.
 *
 * @param src The compressed frame(s)
 * @param srcSize The size of the compressed frame(s)
 * @returns The decompression margin or an error that can be checked with ZSTD_isError().
 */
ZSTDLIB_STATIC_API size_t ZSTD_decompressionMargin(const void* src, size_t srcSize);

/*! ZSTD_DECOMPRESS_MARGIN() :
 * Similar to ZSTD_decompressionMargin(), but instead of computing the margin from
 * the compressed frame, compute it from the original size and the blockSizeLog.
 * See ZSTD_decompressionMargin() for details.
 *
 * WARNING: This macro does not support multi-frame input, the input must be a single
 * zstd frame. If you need that support use the function, or implement it yourself.
 *
 * @param originalSize The original uncompressed size of the data.
 * @param blockSize    The block size == MIN(windowSize, ZSTD_BLOCKSIZE_MAX).
 *                     Unless you explicitly set the windowLog smaller than
 *                     ZSTD_BLOCKSIZELOG_MAX you can just use ZSTD_BLOCKSIZE_MAX.
 */
#define ZSTD_DECOMPRESSION_MARGIN(originalSize, blockSize) ((size_t)(                                              \
        ZSTD_FRAMEHEADERSIZE_MAX                                                              /* Frame header */ + \
        4                                                                                         /* checksum */ + \
        ((originalSize) == 0 ? 0 : 3 * (((originalSize) + (blockSize) - 1) / blockSize)) /* 3 bytes per block */ + \
        (blockSize)                                                                    /* One block of margin */   \
    ))

typedef enum {
  ZSTD_sf_noBlockDelimiters = 0,         /* Representation of ZSTD_Sequence has no block delimiters, sequences only */
  ZSTD_sf_explicitBlockDelimiters = 1    /* Representation of ZSTD_Sequence contains explicit block delimiters */
} ZSTD_sequenceFormat_e;

/*! ZSTD_sequenceBound() :
 * `srcSize` : size of the input buffer
 *  @return : upper-bound for the number of sequences that can be generated
 *            from a buffer of srcSize bytes
 *
 *  note : returns number of sequences - to get bytes, multiply by sizeof(ZSTD_Sequence).
 */
ZSTDLIB_STATIC_API size_t ZSTD_sequenceBound(size_t srcSize);

/*! ZSTD_generateSequences() :
 * WARNING: This function is meant for debugging and informational purposes ONLY!
 * Its implementation is flawed, and it will be deleted in a future version.
 * It is not guaranteed to succeed, as there are several cases where it will give
 * up and fail. You should NOT use this function in production code.
 *
 * This function is deprecated, and will be removed in a future version.
 *
 * Generate sequences using ZSTD_compress2(), given a source buffer.
 *
 * @param zc The compression context to be used for ZSTD_compress2(). Set any
 *           compression parameters you need on this context.
 * @param outSeqs The output sequences buffer of size @p outSeqsSize
 * @param outSeqsSize The size of the output sequences buffer.
 *                    ZSTD_sequenceBound(srcSize) is an upper bound on the number
 *                    of sequences that can be generated.
 * @param src The source buffer to generate sequences from of size @p srcSize.
 * @param srcSize The size of the source buffer.
 *
 * Each block will end with a dummy sequence
 * with offset == 0, matchLength == 0, and litLength == length of last literals.
 * litLength may be == 0, and if so, then the sequence of (of: 0 ml: 0 ll: 0)
 * simply acts as a block delimiter.
 *
 * @returns The number of sequences generated, necessarily less than
 *          ZSTD_sequenceBound(srcSize), or an error code that can be checked
 *          with ZSTD_isError().
 */
ZSTD_DEPRECATED("For debugging only, will be replaced by ZSTD_extractSequences()")
ZSTDLIB_STATIC_API size_t
ZSTD_generateSequences(ZSTD_CCtx* zc,
                       ZSTD_Sequence* outSeqs, size_t outSeqsSize,
                       const void* src, size_t srcSize);

/*! ZSTD_mergeBlockDelimiters() :
 * Given an array of ZSTD_Sequence, remove all sequences that represent block delimiters/last literals
 * by merging them into the literals of the next sequence.
 *
 * As such, the final generated result has no explicit representation of block boundaries,
 * and the final last literals segment is not represented in the sequences.
 *
 * The output of this function can be fed into ZSTD_compressSequences() with CCtx
 * setting of ZSTD_c_blockDelimiters as ZSTD_sf_noBlockDelimiters
 * @return : number of sequences left after merging
 */
ZSTDLIB_STATIC_API size_t ZSTD_mergeBlockDelimiters(ZSTD_Sequence* sequences, size_t seqsSize);

/*! ZSTD_compressSequences() :
 * Compress an array of ZSTD_Sequence, associated with @src buffer, into dst.
 * @src contains the entire input (not just the literals).
 * If @srcSize > sum(sequence.length), the remaining bytes are considered all literals
 * If a dictionary is included, then the cctx should reference the dict. (see: ZSTD_CCtx_refCDict(), ZSTD_CCtx_loadDictionary(), etc.)
 * The entire source is compressed into a single frame.
 *
 * The compression behavior changes based on cctx params. In particular:
 *    If ZSTD_c_blockDelimiters == ZSTD_sf_noBlockDelimiters, the array of ZSTD_Sequence is expected to contain
 *    no block delimiters (defined in ZSTD_Sequence). Block boundaries are roughly determined based on
 *    the block size derived from the cctx, and sequences may be split. This is the default setting.
 *
 *    If ZSTD_c_blockDelimiters == ZSTD_sf_explicitBlockDelimiters, the array of ZSTD_Sequence is expected to contain
 *    block delimiters (defined in ZSTD_Sequence). Behavior is undefined if no block delimiters are provided.
 *
 *    If ZSTD_c_validateSequences == 0, this function will blindly accept the sequences provided. Invalid sequences cause undefined
 *    behavior. If ZSTD_c_validateSequences == 1, then if sequence is invalid (see doc/zstd_compression_format.md for
 *    specifics regarding offset/matchlength requirements) then the function will bail out and return an error.
 *
 *    In addition to the two adjustable experimental params, there are other important cctx params.
 *    - ZSTD_c_minMatch MUST be set as less than or equal to the smallest match generated by the match finder. It has a minimum value of ZSTD_MINMATCH_MIN.
 *    - ZSTD_c_compressionLevel accordingly adjusts the strength of the entropy coder, as it would in typical compression.
 *    - ZSTD_c_windowLog affects offset validation: this function will return an error at higher debug levels if a provided offset
 *      is larger than what the spec allows for a given window log and dictionary (if present). See: doc/zstd_compression_format.md
 *
 * Note: Repcodes are, as of now, always re-calculated within this function, so ZSTD_Sequence::rep is unused.
 * Note 2: Once we integrate ability to ingest repcodes, the explicit block delims mode must respect those repcodes exactly,
 *         and cannot emit an RLE block that disagrees with the repcode history
 * @return : final compressed size, or a ZSTD error code.
 */
ZSTDLIB_STATIC_API size_t
ZSTD_compressSequences( ZSTD_CCtx* cctx, void* dst, size_t dstSize,
                        const ZSTD_Sequence* inSeqs, size_t inSeqsSize,
                        const void* src, size_t srcSize);


/*! ZSTD_writeSkippableFrame() :
 * Generates a zstd skippable frame containing data given by src, and writes it to dst buffer.
 *
 * Skippable frames begin with a 4-byte magic number. There are 16 possible choices of magic number,
 * ranging from ZSTD_MAGIC_SKIPPABLE_START to ZSTD_MAGIC_SKIPPABLE_START+15.
 * As such, the parameter magicVariant controls the exact skippable frame magic number variant used, so
 * the magic number used will be ZSTD_MAGIC_SKIPPABLE_START + magicVariant.
 *
 * Returns an error if destination buffer is not large enough, if the source size is not representable
 * with a 4-byte unsigned int, or if the parameter magicVariant is greater than 15 (and therefore invalid).
 *
 * @return : number of bytes written or a ZSTD error.
 */
ZSTDLIB_STATIC_API size_t ZSTD_writeSkippableFrame(void* dst, size_t dstCapacity,
                                            const void* src, size_t srcSize, unsigned magicVariant);

/*! ZSTD_readSkippableFrame() :
 * Retrieves a zstd skippable frame containing data given by src, and writes it to dst buffer.
 *
 * The parameter magicVariant will receive the magicVariant that was supplied when the frame was written,
 * i.e. magicNumber - ZSTD_MAGIC_SKIPPABLE_START.  This can be NULL if the caller is not interested
 * in the magicVariant.
 *
 * Returns an error if destination buffer is not large enough, or if the frame is not skippable.
 *
 * @return : number of bytes written or a ZSTD error.
 */
ZSTDLIB_API size_t ZSTD_readSkippableFrame(void* dst, size_t dstCapacity, unsigned* magicVariant,
                                            const void* src, size_t srcSize);

/*! ZSTD_isSkippableFrame() :
 *  Tells if the content of `buffer` starts with a valid Frame Identifier for a skippable frame.
 */
ZSTDLIB_API unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size);



/***************************************
*  Memory management
***************************************/

/*! ZSTD_estimate*() :
 *  These functions make it possible to estimate memory usage
 *  of a future {D,C}Ctx, before its creation.
 *  This is useful in combination with ZSTD_initStatic(),
 *  which makes it possible to employ a static buffer for ZSTD_CCtx* state.
 *
 *  ZSTD_estimateCCtxSize() will provide a memory budget large enough
 *  to compress data of any size using one-shot compression ZSTD_compressCCtx() or ZSTD_compress2()
 *  associated with any compression level up to max specified one.
 *  The estimate will assume the input may be arbitrarily large,
 *  which is the worst case.
 *
 *  Note that the size estimation is specific for one-shot compression,
 *  it is not valid for streaming (see ZSTD_estimateCStreamSize*())
 *  nor other potential ways of using a ZSTD_CCtx* state.
 *
 *  When srcSize can be bound by a known and rather "small" value,
 *  this knowledge can be used to provide a tighter budget estimation
 *  because the ZSTD_CCtx* state will need less memory for small inputs.
 *  This tighter estimation can be provided by employing more advanced functions
 *  ZSTD_estimateCCtxSize_usingCParams(), which can be used in tandem with ZSTD_getCParams(),
 *  and ZSTD_estimateCCtxSize_usingCCtxParams(), which can be used in tandem with ZSTD_CCtxParams_setParameter().
 *  Both can be used to estimate memory using custom compression parameters and arbitrary srcSize limits.
 *
 *  Note : only single-threaded compression is supported.
 *  ZSTD_estimateCCtxSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1.
 */
ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize(int maxCompressionLevel);
ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
ZSTDLIB_STATIC_API size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params);
ZSTDLIB_STATIC_API size_t ZSTD_estimateDCtxSize(void);

/*! ZSTD_estimateCStreamSize() :
 *  ZSTD_estimateCStreamSize() will provide a memory budget large enough for streaming compression
 *  using any compression level up to the max specified one.
 *  It will also consider src size to be arbitrarily "large", which is a worst case scenario.
 *  If srcSize is known to always be small, ZSTD_estimateCStreamSize_usingCParams() can provide a tighter estimation.
 *  ZSTD_estimateCStreamSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
 *  ZSTD_estimateCStreamSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParams_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_c_nbWorkers is >= 1.
 *  Note : CStream size estimation is only correct for single-threaded compression.
 *  ZSTD_estimateCStreamSize_usingCCtxParams() will return an error code if ZSTD_c_nbWorkers is >= 1.
 *  Note 2 : ZSTD_estimateCStreamSize* functions are not compatible with the Block-Level Sequence Producer API at this time.
 *  Size estimates assume that no external sequence producer is registered.
 *
 *  ZSTD_DStream memory budget depends on frame's window Size.
 *  This information can be passed manually, using ZSTD_estimateDStreamSize,
 *  or deducted from a valid frame Header, using ZSTD_estimateDStreamSize_fromFrame();
 *  Any frame requesting a window size larger than max specified one will be rejected.
 *  Note : if streaming is init with function ZSTD_init?Stream_usingDict(),
 *         an internal ?Dict will be created, which additional size is not estimated here.
 *         In this case, get total size by adding ZSTD_estimate?DictSize
 */
ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize(int maxCompressionLevel);
ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams);
ZSTDLIB_STATIC_API size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params);
ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize(size_t maxWindowSize);
ZSTDLIB_STATIC_API size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize);

/*! ZSTD_estimate?DictSize() :
 *  ZSTD_estimateCDictSize() will bet that src size is relatively "small", and content is copied, like ZSTD_createCDict().
 *  ZSTD_estimateCDictSize_advanced() makes it possible to control compression parameters precisely, like ZSTD_createCDict_advanced().
 *  Note : dictionaries created by reference (`ZSTD_dlm_byRef`) are logically smaller.
 */
ZSTDLIB_STATIC_API size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel);
ZSTDLIB_STATIC_API size_t ZSTD_estimateCDictSize_advanced(size_t dictSize, ZSTD_compressionParameters cParams, ZSTD_dictLoadMethod_e dictLoadMethod);
ZSTDLIB_STATIC_API size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod);

/*! ZSTD_initStatic*() :
 *  Initialize an object using a pre-allocated fixed-size buffer.
 *  workspace: The memory area to emplace the object into.
 *             Provided pointer *must be 8-bytes aligned*.
 *             Buffer must outlive object.
 *  workspaceSize: Use ZSTD_estimate*Size() to determine
 *                 how large workspace must be to support target scenario.
 * @return : pointer to object (same address as workspace, just different type),
 *           or NULL if error (size too small, incorrect alignment, etc.)
 *  Note : zstd will never resize nor malloc() when using a static buffer.
 *         If the object requires more memory than available,
 *         zstd will just error out (typically ZSTD_error_memory_allocation).
 *  Note 2 : there is no corresponding "free" function.
 *           Since workspace is allocated externally, it must be freed externally too.
 *  Note 3 : cParams : use ZSTD_getCParams() to convert a compression level
 *           into its associated cParams.
 *  Limitation 1 : currently not compatible with internal dictionary creation, triggered by
 *                 ZSTD_CCtx_loadDictionary(), ZSTD_initCStream_usingDict() or ZSTD_initDStream_usingDict().
 *  Limitation 2 : static cctx currently not compatible with multi-threading.
 *  Limitation 3 : static dctx is incompatible with legacy support.
 */
ZSTDLIB_STATIC_API ZSTD_CCtx*    ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize);
ZSTDLIB_STATIC_API ZSTD_CStream* ZSTD_initStaticCStream(void* workspace, size_t workspaceSize);    /**< same as ZSTD_initStaticCCtx() */

ZSTDLIB_STATIC_API ZSTD_DCtx*    ZSTD_initStaticDCtx(void* workspace, size_t workspaceSize);
ZSTDLIB_STATIC_API ZSTD_DStream* ZSTD_initStaticDStream(void* workspace, size_t workspaceSize);    /**< same as ZSTD_initStaticDCtx() */

ZSTDLIB_STATIC_API const ZSTD_CDict* ZSTD_initStaticCDict(
                                        void* workspace, size_t workspaceSize,
                                        const void* dict, size_t dictSize,
                                        ZSTD_dictLoadMethod_e dictLoadMethod,
                                        ZSTD_dictContentType_e dictContentType,
                                        ZSTD_compressionParameters cParams);

ZSTDLIB_STATIC_API const ZSTD_DDict* ZSTD_initStaticDDict(
                                        void* workspace, size_t workspaceSize,
                                        const void* dict, size_t dictSize,
                                        ZSTD_dictLoadMethod_e dictLoadMethod,
                                        ZSTD_dictContentType_e dictContentType);


/*! Custom memory allocation :
 *  These prototypes make it possible to pass your own allocation/free functions.
 *  ZSTD_customMem is provided at creation time, using ZSTD_create*_advanced() variants listed below.
 *  All allocation/free operations will be completed using these custom variants instead of regular <stdlib.h> ones.
 */
typedef void* (*ZSTD_allocFunction) (void* opaque, size_t size);
typedef void  (*ZSTD_freeFunction) (void* opaque, void* address);
typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; void* opaque; } ZSTD_customMem;
static
#ifdef __GNUC__
__attribute__((__unused__))
#endif
ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL };  /**< this constant defers to stdlib's functions */

ZSTDLIB_STATIC_API ZSTD_CCtx*    ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
ZSTDLIB_STATIC_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
ZSTDLIB_STATIC_API ZSTD_DCtx*    ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
ZSTDLIB_STATIC_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);

ZSTDLIB_STATIC_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
                                                  ZSTD_dictLoadMethod_e dictLoadMethod,
                                                  ZSTD_dictContentType_e dictContentType,
                                                  ZSTD_compressionParameters cParams,
                                                  ZSTD_customMem customMem);

/*! Thread pool :
 *  These prototypes make it possible to share a thread pool among multiple compression contexts.
 *  This can limit resources for applications with multiple threads where each one uses
 *  a threaded compression mode (via ZSTD_c_nbWorkers parameter).
 *  ZSTD_createThreadPool creates a new thread pool with a given number of threads.
 *  Note that the lifetime of such pool must exist while being used.
 *  ZSTD_CCtx_refThreadPool assigns a thread pool to a context (use NULL argument value
 *  to use an internal thread pool).
 *  ZSTD_freeThreadPool frees a thread pool, accepts NULL pointer.
 */
typedef struct POOL_ctx_s ZSTD_threadPool;
ZSTDLIB_STATIC_API ZSTD_threadPool* ZSTD_createThreadPool(size_t numThreads);
ZSTDLIB_STATIC_API void ZSTD_freeThreadPool (ZSTD_threadPool* pool);  /* accept NULL pointer */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_refThreadPool(ZSTD_CCtx* cctx, ZSTD_threadPool* pool);


/*
 * This API is temporary and is expected to change or disappear in the future!
 */
ZSTDLIB_STATIC_API ZSTD_CDict* ZSTD_createCDict_advanced2(
    const void* dict, size_t dictSize,
    ZSTD_dictLoadMethod_e dictLoadMethod,
    ZSTD_dictContentType_e dictContentType,
    const ZSTD_CCtx_params* cctxParams,
    ZSTD_customMem customMem);

ZSTDLIB_STATIC_API ZSTD_DDict* ZSTD_createDDict_advanced(
    const void* dict, size_t dictSize,
    ZSTD_dictLoadMethod_e dictLoadMethod,
    ZSTD_dictContentType_e dictContentType,
    ZSTD_customMem customMem);


/***************************************
*  Advanced compression functions
***************************************/

/*! ZSTD_createCDict_byReference() :
 *  Create a digested dictionary for compression
 *  Dictionary content is just referenced, not duplicated.
 *  As a consequence, `dictBuffer` **must** outlive CDict,
 *  and its content must remain unmodified throughout the lifetime of CDict.
 *  note: equivalent to ZSTD_createCDict_advanced(), with dictLoadMethod==ZSTD_dlm_byRef */
ZSTDLIB_STATIC_API ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);

/*! ZSTD_getCParams() :
 * @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
 * `estimatedSrcSize` value is optional, select 0 if not known */
ZSTDLIB_STATIC_API ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);

/*! ZSTD_getParams() :
 *  same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
 *  All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 */
ZSTDLIB_STATIC_API ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);

/*! ZSTD_checkCParams() :
 *  Ensure param values remain within authorized range.
 * @return 0 on success, or an error code (can be checked with ZSTD_isError()) */
ZSTDLIB_STATIC_API size_t ZSTD_checkCParams(ZSTD_compressionParameters params);

/*! ZSTD_adjustCParams() :
 *  optimize params for a given `srcSize` and `dictSize`.
 * `srcSize` can be unknown, in which case use ZSTD_CONTENTSIZE_UNKNOWN.
 * `dictSize` must be `0` when there is no dictionary.
 *  cPar can be invalid : all parameters will be clamped within valid range in the @return struct.
 *  This function never fails (wide contract) */
ZSTDLIB_STATIC_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);

/*! ZSTD_CCtx_setCParams() :
 *  Set all parameters provided within @p cparams into the working @p cctx.
 *  Note : if modifying parameters during compression (MT mode only),
 *         note that changes to the .windowLog parameter will be ignored.
 * @return 0 on success, or an error code (can be checked with ZSTD_isError()).
 *         On failure, no parameters are updated.
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setCParams(ZSTD_CCtx* cctx, ZSTD_compressionParameters cparams);

/*! ZSTD_CCtx_setFParams() :
 *  Set all parameters provided within @p fparams into the working @p cctx.
 * @return 0 on success, or an error code (can be checked with ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setFParams(ZSTD_CCtx* cctx, ZSTD_frameParameters fparams);

/*! ZSTD_CCtx_setParams() :
 *  Set all parameters provided within @p params into the working @p cctx.
 * @return 0 on success, or an error code (can be checked with ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setParams(ZSTD_CCtx* cctx, ZSTD_parameters params);

/*! ZSTD_compress_advanced() :
 *  Note : this function is now DEPRECATED.
 *         It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_setParameter() and other parameter setters.
 *  This prototype will generate compilation warnings. */
ZSTD_DEPRECATED("use ZSTD_compress2")
ZSTDLIB_STATIC_API
size_t ZSTD_compress_advanced(ZSTD_CCtx* cctx,
                              void* dst, size_t dstCapacity,
                        const void* src, size_t srcSize,
                        const void* dict,size_t dictSize,
                              ZSTD_parameters params);

/*! ZSTD_compress_usingCDict_advanced() :
 *  Note : this function is now DEPRECATED.
 *         It can be replaced by ZSTD_compress2(), in combination with ZSTD_CCtx_loadDictionary() and other parameter setters.
 *  This prototype will generate compilation warnings. */
ZSTD_DEPRECATED("use ZSTD_compress2 with ZSTD_CCtx_loadDictionary")
ZSTDLIB_STATIC_API
size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
                                              void* dst, size_t dstCapacity,
                                        const void* src, size_t srcSize,
                                        const ZSTD_CDict* cdict,
                                              ZSTD_frameParameters fParams);


/*! ZSTD_CCtx_loadDictionary_byReference() :
 *  Same as ZSTD_CCtx_loadDictionary(), but dictionary content is referenced, instead of being copied into CCtx.
 *  It saves some memory, but also requires that `dict` outlives its usage within `cctx` */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_loadDictionary_byReference(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);

/*! ZSTD_CCtx_loadDictionary_advanced() :
 *  Same as ZSTD_CCtx_loadDictionary(), but gives finer control over
 *  how to load the dictionary (by copy ? by reference ?)
 *  and how to interpret it (automatic ? force raw mode ? full mode only ?) */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_loadDictionary_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);

/*! ZSTD_CCtx_refPrefix_advanced() :
 *  Same as ZSTD_CCtx_refPrefix(), but gives finer control over
 *  how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);

/* ===   experimental parameters   === */
/* these parameters can be used with ZSTD_setParameter()
 * they are not guaranteed to remain supported in the future */

 /* Enables rsyncable mode,
  * which makes compressed files more rsync friendly
  * by adding periodic synchronization points to the compressed data.
  * The target average block size is ZSTD_c_jobSize / 2.
  * It's possible to modify the job size to increase or decrease
  * the granularity of the synchronization point.
  * Once the jobSize is smaller than the window size,
  * it will result in compression ratio degradation.
  * NOTE 1: rsyncable mode only works when multithreading is enabled.
  * NOTE 2: rsyncable performs poorly in combination with long range mode,
  * since it will decrease the effectiveness of synchronization points,
  * though mileage may vary.
  * NOTE 3: Rsyncable mode limits maximum compression speed to ~400 MB/s.
  * If the selected compression level is already running significantly slower,
  * the overall speed won't be significantly impacted.
  */
 #define ZSTD_c_rsyncable ZSTD_c_experimentalParam1

/* Select a compression format.
 * The value must be of type ZSTD_format_e.
 * See ZSTD_format_e enum definition for details */
#define ZSTD_c_format ZSTD_c_experimentalParam2

/* Force back-reference distances to remain < windowSize,
 * even when referencing into Dictionary content (default:0) */
#define ZSTD_c_forceMaxWindow ZSTD_c_experimentalParam3

/* Controls whether the contents of a CDict
 * are used in place, or copied into the working context.
 * Accepts values from the ZSTD_dictAttachPref_e enum.
 * See the comments on that enum for an explanation of the feature. */
#define ZSTD_c_forceAttachDict ZSTD_c_experimentalParam4

/* Controlled with ZSTD_paramSwitch_e enum.
 * Default is ZSTD_ps_auto.
 * Set to ZSTD_ps_disable to never compress literals.
 * Set to ZSTD_ps_enable to always compress literals. (Note: uncompressed literals
 * may still be emitted if huffman is not beneficial to use.)
 *
 * By default, in ZSTD_ps_auto, the library will decide at runtime whether to use
 * literals compression based on the compression parameters - specifically,
 * negative compression levels do not use literal compression.
 */
#define ZSTD_c_literalCompressionMode ZSTD_c_experimentalParam5

/* User's best guess of source size.
 * Hint is not valid when srcSizeHint == 0.
 * There is no guarantee that hint is close to actual source size,
 * but compression ratio may regress significantly if guess considerably underestimates */
#define ZSTD_c_srcSizeHint ZSTD_c_experimentalParam7

/* Controls whether the new and experimental "dedicated dictionary search
 * structure" can be used. This feature is still rough around the edges, be
 * prepared for surprising behavior!
 *
 * How to use it:
 *
 * When using a CDict, whether to use this feature or not is controlled at
 * CDict creation, and it must be set in a CCtxParams set passed into that
 * construction (via ZSTD_createCDict_advanced2()). A compression will then
 * use the feature or not based on how the CDict was constructed; the value of
 * this param, set in the CCtx, will have no effect.
 *
 * However, when a dictionary buffer is passed into a CCtx, such as via
 * ZSTD_CCtx_loadDictionary(), this param can be set on the CCtx to control
 * whether the CDict that is created internally can use the feature or not.
 *
 * What it does:
 *
 * Normally, the internal data structures of the CDict are analogous to what
 * would be stored in a CCtx after compressing the contents of a dictionary.
 * To an approximation, a compression using a dictionary can then use those
 * data structures to simply continue what is effectively a streaming
 * compression where the simulated compression of the dictionary left off.
 * Which is to say, the search structures in the CDict are normally the same
 * format as in the CCtx.
 *
 * It is possible to do better, since the CDict is not like a CCtx: the search
 * structures are written once during CDict creation, and then are only read
 * after that, while the search structures in the CCtx are both read and
 * written as the compression goes along. This means we can choose a search
 * structure for the dictionary that is read-optimized.
 *
 * This feature enables the use of that different structure.
 *
 * Note that some of the members of the ZSTD_compressionParameters struct have
 * different semantics and constraints in the dedicated search structure. It is
 * highly recommended that you simply set a compression level in the CCtxParams
 * you pass into the CDict creation call, and avoid messing with the cParams
 * directly.
 *
 * Effects:
 *
 * This will only have any effect when the selected ZSTD_strategy
 * implementation supports this feature. Currently, that's limited to
 * ZSTD_greedy, ZSTD_lazy, and ZSTD_lazy2.
 *
 * Note that this means that the CDict tables can no longer be copied into the
 * CCtx, so the dict attachment mode ZSTD_dictForceCopy will no longer be
 * usable. The dictionary can only be attached or reloaded.
 *
 * In general, you should expect compression to be faster--sometimes very much
 * so--and CDict creation to be slightly slower. Eventually, we will probably
 * make this mode the default.
 */
#define ZSTD_c_enableDedicatedDictSearch ZSTD_c_experimentalParam8

/* ZSTD_c_stableInBuffer
 * Experimental parameter.
 * Default is 0 == disabled. Set to 1 to enable.
 *
 * Tells the compressor that input data presented with ZSTD_inBuffer
 * will ALWAYS be the same between calls.
 * Technically, the @src pointer must never be changed,
 * and the @pos field can only be updated by zstd.
 * However, it's possible to increase the @size field,
 * allowing scenarios where more data can be appended after compressions starts.
 * These conditions are checked by the compressor,
 * and compression will fail if they are not respected.
 * Also, data in the ZSTD_inBuffer within the range [src, src + pos)
 * MUST not be modified during compression or it will result in data corruption.
 *
 * When this flag is enabled zstd won't allocate an input window buffer,
 * because the user guarantees it can reference the ZSTD_inBuffer until
 * the frame is complete. But, it will still allocate an output buffer
 * large enough to fit a block (see ZSTD_c_stableOutBuffer). This will also
 * avoid the memcpy() from the input buffer to the input window buffer.
 *
 * NOTE: So long as the ZSTD_inBuffer always points to valid memory, using
 * this flag is ALWAYS memory safe, and will never access out-of-bounds
 * memory. However, compression WILL fail if conditions are not respected.
 *
 * WARNING: The data in the ZSTD_inBuffer in the range [src, src + pos) MUST
 * not be modified during compression or it will result in data corruption.
 * This is because zstd needs to reference data in the ZSTD_inBuffer to find
 * matches. Normally zstd maintains its own window buffer for this purpose,
 * but passing this flag tells zstd to rely on user provided buffer instead.
 */
#define ZSTD_c_stableInBuffer ZSTD_c_experimentalParam9

/* ZSTD_c_stableOutBuffer
 * Experimental parameter.
 * Default is 0 == disabled. Set to 1 to enable.
 *
 * Tells he compressor that the ZSTD_outBuffer will not be resized between
 * calls. Specifically: (out.size - out.pos) will never grow. This gives the
 * compressor the freedom to say: If the compressed data doesn't fit in the
 * output buffer then return ZSTD_error_dstSizeTooSmall. This allows us to
 * always decompress directly into the output buffer, instead of decompressing
 * into an internal buffer and copying to the output buffer.
 *
 * When this flag is enabled zstd won't allocate an output buffer, because
 * it can write directly to the ZSTD_outBuffer. It will still allocate the
 * input window buffer (see ZSTD_c_stableInBuffer).
 *
 * Zstd will check that (out.size - out.pos) never grows and return an error
 * if it does. While not strictly necessary, this should prevent surprises.
 */
#define ZSTD_c_stableOutBuffer ZSTD_c_experimentalParam10

/* ZSTD_c_blockDelimiters
 * Default is 0 == ZSTD_sf_noBlockDelimiters.
 *
 * For use with sequence compression API: ZSTD_compressSequences().
 *
 * Designates whether or not the given array of ZSTD_Sequence contains block delimiters
 * and last literals, which are defined as sequences with offset == 0 and matchLength == 0.
 * See the definition of ZSTD_Sequence for more specifics.
 */
#define ZSTD_c_blockDelimiters ZSTD_c_experimentalParam11

/* ZSTD_c_validateSequences
 * Default is 0 == disabled. Set to 1 to enable sequence validation.
 *
 * For use with sequence compression API: ZSTD_compressSequences().
 * Designates whether or not we validate sequences provided to ZSTD_compressSequences()
 * during function execution.
 *
 * Without validation, providing a sequence that does not conform to the zstd spec will cause
 * undefined behavior, and may produce a corrupted block.
 *
 * With validation enabled, if sequence is invalid (see doc/zstd_compression_format.md for
 * specifics regarding offset/matchlength requirements) then the function will bail out and
 * return an error.
 *
 */
#define ZSTD_c_validateSequences ZSTD_c_experimentalParam12

/* ZSTD_c_useBlockSplitter
 * Controlled with ZSTD_paramSwitch_e enum.
 * Default is ZSTD_ps_auto.
 * Set to ZSTD_ps_disable to never use block splitter.
 * Set to ZSTD_ps_enable to always use block splitter.
 *
 * By default, in ZSTD_ps_auto, the library will decide at runtime whether to use
 * block splitting based on the compression parameters.
 */
#define ZSTD_c_useBlockSplitter ZSTD_c_experimentalParam13

/* ZSTD_c_useRowMatchFinder
 * Controlled with ZSTD_paramSwitch_e enum.
 * Default is ZSTD_ps_auto.
 * Set to ZSTD_ps_disable to never use row-based matchfinder.
 * Set to ZSTD_ps_enable to force usage of row-based matchfinder.
 *
 * By default, in ZSTD_ps_auto, the library will decide at runtime whether to use
 * the row-based matchfinder based on support for SIMD instructions and the window log.
 * Note that this only pertains to compression strategies: greedy, lazy, and lazy2
 */
#define ZSTD_c_useRowMatchFinder ZSTD_c_experimentalParam14

/* ZSTD_c_deterministicRefPrefix
 * Default is 0 == disabled. Set to 1 to enable.
 *
 * Zstd produces different results for prefix compression when the prefix is
 * directly adjacent to the data about to be compressed vs. when it isn't.
 * This is because zstd detects that the two buffers are contiguous and it can
 * use a more efficient match finding algorithm. However, this produces different
 * results than when the two buffers are non-contiguous. This flag forces zstd
 * to always load the prefix in non-contiguous mode, even if it happens to be
 * adjacent to the data, to guarantee determinism.
 *
 * If you really care about determinism when using a dictionary or prefix,
 * like when doing delta compression, you should select this option. It comes
 * at a speed penalty of about ~2.5% if the dictionary and data happened to be
 * contiguous, and is free if they weren't contiguous. We don't expect that
 * intentionally making the dictionary and data contiguous will be worth the
 * cost to memcpy() the data.
 */
#define ZSTD_c_deterministicRefPrefix ZSTD_c_experimentalParam15

/* ZSTD_c_prefetchCDictTables
 * Controlled with ZSTD_paramSwitch_e enum. Default is ZSTD_ps_auto.
 *
 * In some situations, zstd uses CDict tables in-place rather than copying them
 * into the working context. (See docs on ZSTD_dictAttachPref_e above for details).
 * In such situations, compression speed is seriously impacted when CDict tables are
 * "cold" (outside CPU cache). This parameter instructs zstd to prefetch CDict tables
 * when they are used in-place.
 *
 * For sufficiently small inputs, the cost of the prefetch will outweigh the benefit.
 * For sufficiently large inputs, zstd will by default memcpy() CDict tables
 * into the working context, so there is no need to prefetch. This parameter is
 * targeted at a middle range of input sizes, where a prefetch is cheap enough to be
 * useful but memcpy() is too expensive. The exact range of input sizes where this
 * makes sense is best determined by careful experimentation.
 *
 * Note: for this parameter, ZSTD_ps_auto is currently equivalent to ZSTD_ps_disable,
 * but in the future zstd may conditionally enable this feature via an auto-detection
 * heuristic for cold CDicts.
 * Use ZSTD_ps_disable to opt out of prefetching under any circumstances.
 */
#define ZSTD_c_prefetchCDictTables ZSTD_c_experimentalParam16

/* ZSTD_c_enableSeqProducerFallback
 * Allowed values are 0 (disable) and 1 (enable). The default setting is 0.
 *
 * Controls whether zstd will fall back to an internal sequence producer if an
 * external sequence producer is registered and returns an error code. This fallback
 * is block-by-block: the internal sequence producer will only be called for blocks
 * where the external sequence producer returns an error code. Fallback parsing will
 * follow any other cParam settings, such as compression level, the same as in a
 * normal (fully-internal) compression operation.
 *
 * The user is strongly encouraged to read the full Block-Level Sequence Producer API
 * documentation (below) before setting this parameter. */
#define ZSTD_c_enableSeqProducerFallback ZSTD_c_experimentalParam17

/* ZSTD_c_maxBlockSize
 * Allowed values are between 1KB and ZSTD_BLOCKSIZE_MAX (128KB).
 * The default is ZSTD_BLOCKSIZE_MAX, and setting to 0 will set to the default.
 *
 * This parameter can be used to set an upper bound on the blocksize
 * that overrides the default ZSTD_BLOCKSIZE_MAX. It cannot be used to set upper
 * bounds greater than ZSTD_BLOCKSIZE_MAX or bounds lower than 1KB (will make
 * compressBound() inaccurate). Only currently meant to be used for testing.
 *
 */
#define ZSTD_c_maxBlockSize ZSTD_c_experimentalParam18

/* ZSTD_c_searchForExternalRepcodes
 * This parameter affects how zstd parses external sequences, such as sequences
 * provided through the compressSequences() API or from an external block-level
 * sequence producer.
 *
 * If set to ZSTD_ps_enable, the library will check for repeated offsets in
 * external sequences, even if those repcodes are not explicitly indicated in
 * the "rep" field. Note that this is the only way to exploit repcode matches
 * while using compressSequences() or an external sequence producer, since zstd
 * currently ignores the "rep" field of external sequences.
 *
 * If set to ZSTD_ps_disable, the library will not exploit repeated offsets in
 * external sequences, regardless of whether the "rep" field has been set. This
 * reduces sequence compression overhead by about 25% while sacrificing some
 * compression ratio.
 *
 * The default value is ZSTD_ps_auto, for which the library will enable/disable
 * based on compression level.
 *
 * Note: for now, this param only has an effect if ZSTD_c_blockDelimiters is
 * set to ZSTD_sf_explicitBlockDelimiters. That may change in the future.
 */
#define ZSTD_c_searchForExternalRepcodes ZSTD_c_experimentalParam19

/*! ZSTD_CCtx_getParameter() :
 *  Get the requested compression parameter value, selected by enum ZSTD_cParameter,
 *  and store it into int* value.
 * @return : 0, or an error code (which can be tested with ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_getParameter(const ZSTD_CCtx* cctx, ZSTD_cParameter param, int* value);


/*! ZSTD_CCtx_params :
 *  Quick howto :
 *  - ZSTD_createCCtxParams() : Create a ZSTD_CCtx_params structure
 *  - ZSTD_CCtxParams_setParameter() : Push parameters one by one into
 *                                     an existing ZSTD_CCtx_params structure.
 *                                     This is similar to
 *                                     ZSTD_CCtx_setParameter().
 *  - ZSTD_CCtx_setParametersUsingCCtxParams() : Apply parameters to
 *                                    an existing CCtx.
 *                                    These parameters will be applied to
 *                                    all subsequent frames.
 *  - ZSTD_compressStream2() : Do compression using the CCtx.
 *  - ZSTD_freeCCtxParams() : Free the memory, accept NULL pointer.
 *
 *  This can be used with ZSTD_estimateCCtxSize_advanced_usingCCtxParams()
 *  for static allocation of CCtx for single-threaded compression.
 */
ZSTDLIB_STATIC_API ZSTD_CCtx_params* ZSTD_createCCtxParams(void);
ZSTDLIB_STATIC_API size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params);  /* accept NULL pointer */

/*! ZSTD_CCtxParams_reset() :
 *  Reset params to default values.
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params);

/*! ZSTD_CCtxParams_init() :
 *  Initializes the compression parameters of cctxParams according to
 *  compression level. All other parameters are reset to their default values.
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel);

/*! ZSTD_CCtxParams_init_advanced() :
 *  Initializes the compression and frame parameters of cctxParams according to
 *  params. All other parameters are reset to their default values.
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);

/*! ZSTD_CCtxParams_setParameter() : Requires v1.4.0+
 *  Similar to ZSTD_CCtx_setParameter.
 *  Set one compression parameter, selected by enum ZSTD_cParameter.
 *  Parameters must be applied to a ZSTD_CCtx using
 *  ZSTD_CCtx_setParametersUsingCCtxParams().
 * @result : a code representing success or failure (which can be tested with
 *           ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, int value);

/*! ZSTD_CCtxParams_getParameter() :
 * Similar to ZSTD_CCtx_getParameter.
 * Get the requested value of one compression parameter, selected by enum ZSTD_cParameter.
 * @result : 0, or an error code (which can be tested with ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtxParams_getParameter(const ZSTD_CCtx_params* params, ZSTD_cParameter param, int* value);

/*! ZSTD_CCtx_setParametersUsingCCtxParams() :
 *  Apply a set of ZSTD_CCtx_params to the compression context.
 *  This can be done even after compression is started,
 *    if nbWorkers==0, this will have no impact until a new compression is started.
 *    if nbWorkers>=1, new parameters will be picked up at next job,
 *       with a few restrictions (windowLog, pledgedSrcSize, nbWorkers, jobSize, and overlapLog are not updated).
 */
ZSTDLIB_STATIC_API size_t ZSTD_CCtx_setParametersUsingCCtxParams(
        ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params);

/*! ZSTD_compressStream2_simpleArgs() :
 *  Same as ZSTD_compressStream2(),
 *  but using only integral types as arguments.
 *  This variant might be helpful for binders from dynamic languages
 *  which have troubles handling structures containing memory pointers.
 */
ZSTDLIB_STATIC_API size_t ZSTD_compressStream2_simpleArgs (
                            ZSTD_CCtx* cctx,
                            void* dst, size_t dstCapacity, size_t* dstPos,
                      const void* src, size_t srcSize, size_t* srcPos,
                            ZSTD_EndDirective endOp);


/***************************************
*  Advanced decompression functions
***************************************/

/*! ZSTD_isFrame() :
 *  Tells if the content of `buffer` starts with a valid Frame Identifier.
 *  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
 *  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
 *  Note 3 : Skippable Frame Identifiers are considered valid. */
ZSTDLIB_STATIC_API unsigned ZSTD_isFrame(const void* buffer, size_t size);

/*! ZSTD_createDDict_byReference() :
 *  Create a digested dictionary, ready to start decompression operation without startup delay.
 *  Dictionary content is referenced, and therefore stays in dictBuffer.
 *  It is important that dictBuffer outlives DDict,
 *  it must remain read accessible throughout the lifetime of DDict */
ZSTDLIB_STATIC_API ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize);

/*! ZSTD_DCtx_loadDictionary_byReference() :
 *  Same as ZSTD_DCtx_loadDictionary(),
 *  but references `dict` content instead of copying it into `dctx`.
 *  This saves memory if `dict` remains around.,
 *  However, it's imperative that `dict` remains accessible (and unmodified) while being used, so it must outlive decompression. */
ZSTDLIB_STATIC_API size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);

/*! ZSTD_DCtx_loadDictionary_advanced() :
 *  Same as ZSTD_DCtx_loadDictionary(),
 *  but gives direct control over
 *  how to load the dictionary (by copy ? by reference ?)
 *  and how to interpret it (automatic ? force raw mode ? full mode only ?). */
ZSTDLIB_STATIC_API size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);

/*! ZSTD_DCtx_refPrefix_advanced() :
 *  Same as ZSTD_DCtx_refPrefix(), but gives finer control over
 *  how to interpret prefix content (automatic ? force raw mode (default) ? full mode only ?) */
ZSTDLIB_STATIC_API size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);

/*! ZSTD_DCtx_setMaxWindowSize() :
 *  Refuses allocating internal buffers for frames requiring a window size larger than provided limit.
 *  This protects a decoder context from reserving too much memory for itself (potential attack scenario).
 *  This parameter is only useful in streaming mode, since no internal buffer is allocated in single-pass mode.
 *  By default, a decompression context accepts all window sizes <= (1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT)
 * @return : 0, or an error code (which can be tested using ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize);

/*! ZSTD_DCtx_getParameter() :
 *  Get the requested decompression parameter value, selected by enum ZSTD_dParameter,
 *  and store it into int* value.
 * @return : 0, or an error code (which can be tested with ZSTD_isError()).
 */
ZSTDLIB_STATIC_API size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int* value);

/* ZSTD_d_format
 * experimental parameter,
 * allowing selection between ZSTD_format_e input compression formats
 */
#define ZSTD_d_format ZSTD_d_experimentalParam1
/* ZSTD_d_stableOutBuffer
 * Experimental parameter.
 * Default is 0 == disabled. Set to 1 to enable.
 *
 * Tells the decompressor that the ZSTD_outBuffer will ALWAYS be the same
 * between calls, except for the modifications that zstd makes to pos (the
 * caller must not modify pos). This is checked by the decompressor, and
 * decompression will fail if it ever changes. Therefore the ZSTD_outBuffer
 * MUST be large enough to fit the entire decompressed frame. This will be
 * checked when the frame content size is known. The data in the ZSTD_outBuffer
 * in the range [dst, dst + pos) MUST not be modified during decompression
 * or you will get data corruption.
 *
 * When this flag is enabled zstd won't allocate an output buffer, because
 * it can write directly to the ZSTD_outBuffer, but it will still allocate
 * an input buffer large enough to fit any compressed block. This will also
 * avoid the memcpy() from the internal output buffer to the ZSTD_outBuffer.
 * If you need to avoid the input buffer allocation use the buffer-less
 * streaming API.
 *
 * NOTE: So long as the ZSTD_outBuffer always points to valid memory, using
 * this flag is ALWAYS memory safe, and will never access out-of-bounds
 * memory. However, decompression WILL fail if you violate the preconditions.
 *
 * WARNING: The data in the ZSTD_outBuffer in the range [dst, dst + pos) MUST
 * not be modified during decompression or you will get data corruption. This
 * is because zstd needs to reference data in the ZSTD_outBuffer to regenerate
 * matches. Normally zstd maintains its own buffer for this purpose, but passing
 * this flag tells zstd to use the user provided buffer.
 */
#define ZSTD_d_stableOutBuffer ZSTD_d_experimentalParam2

/* ZSTD_d_forceIgnoreChecksum
 * Experimental parameter.
 * Default is 0 == disabled. Set to 1 to enable
 *
 * Tells the decompressor to skip checksum validation during decompression, regardless
 * of whether checksumming was specified during compression. This offers some
 * slight performance benefits, and may be useful for debugging.
 * Param has values of type ZSTD_forceIgnoreChecksum_e
 */
#define ZSTD_d_forceIgnoreChecksum ZSTD_d_experimentalParam3

/* ZSTD_d_refMultipleDDicts
 * Experimental parameter.
 * Default is 0 == disabled. Set to 1 to enable
 *
 * If enabled and dctx is allocated on the heap, then additional memory will be allocated
 * to store references to multiple ZSTD_DDict. That is, multiple calls of ZSTD_refDDict()
 * using a given ZSTD_DCtx, rather than overwriting the previous DDict reference, will instead
 * store all references. At decompression time, the appropriate dictID is selected
 * from the set of DDicts based on the dictID in the frame.
 *
 * Usage is simply calling ZSTD_refDDict() on multiple dict buffers.
 *
 * Param has values of byte ZSTD_refMultipleDDicts_e
 *
 * WARNING: Enabling this parameter and calling ZSTD_DCtx_refDDict(), will trigger memory
 * allocation for the hash table. ZSTD_freeDCtx() also frees this memory.
 * Memory is allocated as per ZSTD_DCtx::customMem.
 *
 * Although this function allocates memory for the table, the user is still responsible for
 * memory management of the underlying ZSTD_DDict* themselves.
 */
#define ZSTD_d_refMultipleDDicts ZSTD_d_experimentalParam4

/* ZSTD_d_disableHuffmanAssembly
 * Set to 1 to disable the Huffman assembly implementation.
 * The default value is 0, which allows zstd to use the Huffman assembly
 * implementation if available.
 *
 * This parameter can be used to disable Huffman assembly at runtime.
 * If you want to disable it at compile time you can define the macro
 * ZSTD_DISABLE_ASM.
 */
#define ZSTD_d_disableHuffmanAssembly ZSTD_d_experimentalParam5

/* ZSTD_d_maxBlockSize
 * Allowed values are between 1KB and ZSTD_BLOCKSIZE_MAX (128KB).
 * The default is ZSTD_BLOCKSIZE_MAX, and setting to 0 will set to the default.
 *
 * Forces the decompressor to reject blocks whose content size is
 * larger than the configured maxBlockSize. When maxBlockSize is
 * larger than the windowSize, the windowSize is used instead.
 * This saves memory on the decoder when you know all blocks are small.
 *
 * This option is typically used in conjunction with ZSTD_c_maxBlockSize.
 *
 * WARNING: This causes the decoder to reject otherwise valid frames
 * that have block sizes larger than the configured maxBlockSize.
 */
#define ZSTD_d_maxBlockSize ZSTD_d_experimentalParam6


/*! ZSTD_DCtx_setFormat() :
 *  This function is REDUNDANT. Prefer ZSTD_DCtx_setParameter().
 *  Instruct the decoder context about what kind of data to decode next.
 *  This instruction is mandatory to decode data without a fully-formed header,
 *  such ZSTD_f_zstd1_magicless for example.
 * @return : 0, or an error code (which can be tested using ZSTD_isError()). */
ZSTD_DEPRECATED("use ZSTD_DCtx_setParameter() instead")
ZSTDLIB_STATIC_API
size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format);

/*! ZSTD_decompressStream_simpleArgs() :
 *  Same as ZSTD_decompressStream(),
 *  but using only integral types as arguments.
 *  This can be helpful for binders from dynamic languages
 *  which have troubles handling structures containing memory pointers.
 */
ZSTDLIB_STATIC_API size_t ZSTD_decompressStream_simpleArgs (
                            ZSTD_DCtx* dctx,
                            void* dst, size_t dstCapacity, size_t* dstPos,
                      const void* src, size_t srcSize, size_t* srcPos);


/********************************************************************
*  Advanced streaming functions
*  Warning : most of these functions are now redundant with the Advanced API.
*  Once Advanced API reaches "stable" status,
*  redundant functions will be deprecated, and then at some point removed.
********************************************************************/

/*=====   Advanced Streaming compression functions  =====*/

/*! ZSTD_initCStream_srcSize() :
 * This function is DEPRECATED, and equivalent to:
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_refCDict(zcs, NULL); // clear the dictionary (if any)
 *     ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
 *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
 *
 * pledgedSrcSize must be correct. If it is not known at init time, use
 * ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs,
 * "0" also disables frame content size field. It may be enabled in the future.
 * This prototype will generate compilation warnings.
 */
ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API
size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs,
                         int compressionLevel,
                         unsigned long long pledgedSrcSize);

/*! ZSTD_initCStream_usingDict() :
 * This function is DEPRECATED, and is equivalent to:
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_setParameter(zcs, ZSTD_c_compressionLevel, compressionLevel);
 *     ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
 *
 * Creates of an internal CDict (incompatible with static CCtx), except if
 * dict == NULL or dictSize < 8, in which case no dict is used.
 * Note: dict is loaded with ZSTD_dct_auto (treated as a full zstd dictionary if
 * it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.
 * This prototype will generate compilation warnings.
 */
ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API
size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs,
                     const void* dict, size_t dictSize,
                           int compressionLevel);

/*! ZSTD_initCStream_advanced() :
 * This function is DEPRECATED, and is equivalent to:
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_setParams(zcs, params);
 *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
 *     ZSTD_CCtx_loadDictionary(zcs, dict, dictSize);
 *
 * dict is loaded with ZSTD_dct_auto and ZSTD_dlm_byCopy.
 * pledgedSrcSize must be correct.
 * If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN.
 * This prototype will generate compilation warnings.
 */
ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API
size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs,
                    const void* dict, size_t dictSize,
                          ZSTD_parameters params,
                          unsigned long long pledgedSrcSize);

/*! ZSTD_initCStream_usingCDict() :
 * This function is DEPRECATED, and equivalent to:
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_refCDict(zcs, cdict);
 *
 * note : cdict will just be referenced, and must outlive compression session
 * This prototype will generate compilation warnings.
 */
ZSTD_DEPRECATED("use ZSTD_CCtx_reset and ZSTD_CCtx_refCDict, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API
size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);

/*! ZSTD_initCStream_usingCDict_advanced() :
 *   This function is DEPRECATED, and is equivalent to:
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_setFParams(zcs, fParams);
 *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
 *     ZSTD_CCtx_refCDict(zcs, cdict);
 *
 * same as ZSTD_initCStream_usingCDict(), with control over frame parameters.
 * pledgedSrcSize must be correct. If srcSize is not known at init time, use
 * value ZSTD_CONTENTSIZE_UNKNOWN.
 * This prototype will generate compilation warnings.
 */
ZSTD_DEPRECATED("use ZSTD_CCtx_reset and ZSTD_CCtx_refCDict, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API
size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs,
                               const ZSTD_CDict* cdict,
                                     ZSTD_frameParameters fParams,
                                     unsigned long long pledgedSrcSize);

/*! ZSTD_resetCStream() :
 * This function is DEPRECATED, and is equivalent to:
 *     ZSTD_CCtx_reset(zcs, ZSTD_reset_session_only);
 *     ZSTD_CCtx_setPledgedSrcSize(zcs, pledgedSrcSize);
 * Note: ZSTD_resetCStream() interprets pledgedSrcSize == 0 as ZSTD_CONTENTSIZE_UNKNOWN, but
 *       ZSTD_CCtx_setPledgedSrcSize() does not do the same, so ZSTD_CONTENTSIZE_UNKNOWN must be
 *       explicitly specified.
 *
 *  start a new frame, using same parameters from previous frame.
 *  This is typically useful to skip dictionary loading stage, since it will reuse it in-place.
 *  Note that zcs must be init at least once before using ZSTD_resetCStream().
 *  If pledgedSrcSize is not known at reset time, use macro ZSTD_CONTENTSIZE_UNKNOWN.
 *  If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end.
 *  For the time being, pledgedSrcSize==0 is interpreted as "srcSize unknown" for compatibility with older programs,
 *  but it will change to mean "empty" in future version, so use macro ZSTD_CONTENTSIZE_UNKNOWN instead.
 * @return : 0, or an error code (which can be tested using ZSTD_isError())
 *  This prototype will generate compilation warnings.
 */
ZSTD_DEPRECATED("use ZSTD_CCtx_reset, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API
size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize);


typedef struct {
    unsigned long long ingested;   /* nb input bytes read and buffered */
    unsigned long long consumed;   /* nb input bytes actually compressed */
    unsigned long long produced;   /* nb of compressed bytes generated and buffered */
    unsigned long long flushed;    /* nb of compressed bytes flushed : not provided; can be tracked from caller side */
    unsigned currentJobID;         /* MT only : latest started job nb */
    unsigned nbActiveWorkers;      /* MT only : nb of workers actively compressing at probe time */
} ZSTD_frameProgression;

/* ZSTD_getFrameProgression() :
 * tells how much data has been ingested (read from input)
 * consumed (input actually compressed) and produced (output) for current frame.
 * Note : (ingested - consumed) is amount of input data buffered internally, not yet compressed.
 * Aggregates progression inside active worker threads.
 */
ZSTDLIB_STATIC_API ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx);

/*! ZSTD_toFlushNow() :
 *  Tell how many bytes are ready to be flushed immediately.
 *  Useful for multithreading scenarios (nbWorkers >= 1).
 *  Probe the oldest active job, defined as oldest job not yet entirely flushed,
 *  and check its output buffer.
 * @return : amount of data stored in oldest job and ready to be flushed immediately.
 *  if @return == 0, it means either :
 *  + there is no active job (could be checked with ZSTD_frameProgression()), or
 *  + oldest job is still actively compressing data,
 *    but everything it has produced has also been flushed so far,
 *    therefore flush speed is limited by production speed of oldest job
 *    irrespective of the speed of concurrent (and newer) jobs.
 */
ZSTDLIB_STATIC_API size_t ZSTD_toFlushNow(ZSTD_CCtx* cctx);


/*=====   Advanced Streaming decompression functions  =====*/

/*!
 * This function is deprecated, and is equivalent to:
 *
 *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
 *     ZSTD_DCtx_loadDictionary(zds, dict, dictSize);
 *
 * note: no dictionary will be used if dict == NULL or dictSize < 8
 */
ZSTD_DEPRECATED("use ZSTD_DCtx_reset + ZSTD_DCtx_loadDictionary, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);

/*!
 * This function is deprecated, and is equivalent to:
 *
 *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
 *     ZSTD_DCtx_refDDict(zds, ddict);
 *
 * note : ddict is referenced, it must outlive decompression session
 */
ZSTD_DEPRECATED("use ZSTD_DCtx_reset + ZSTD_DCtx_refDDict, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);

/*!
 * This function is deprecated, and is equivalent to:
 *
 *     ZSTD_DCtx_reset(zds, ZSTD_reset_session_only);
 *
 * reuse decompression parameters from previous init; saves dictionary loading
 */
ZSTD_DEPRECATED("use ZSTD_DCtx_reset, see zstd.h for detailed instructions")
ZSTDLIB_STATIC_API size_t ZSTD_resetDStream(ZSTD_DStream* zds);


/* ********************* BLOCK-LEVEL SEQUENCE PRODUCER API *********************
 *
 * *** OVERVIEW ***
 * The Block-Level Sequence Producer API allows users to provide their own custom
 * sequence producer which libzstd invokes to process each block. The produced list
 * of sequences (literals and matches) is then post-processed by libzstd to produce
 * valid compressed blocks.
 *
 * This block-level offload API is a more granular complement of the existing
 * frame-level offload API compressSequences() (introduced in v1.5.1). It offers
 * an easier migration story for applications already integrated with libzstd: the
 * user application continues to invoke the same compression functions
 * ZSTD_compress2() or ZSTD_compressStream2() as usual, and transparently benefits
 * from the specific advantages of the external sequence producer. For example,
 * the sequence producer could be tuned to take advantage of known characteristics
 * of the input, to offer better speed / ratio, or could leverage hardware
 * acceleration not available within libzstd itself.
 *
 * See contrib/externalSequenceProducer for an example program employing the
 * Block-Level Sequence Producer API.
 *
 * *** USAGE ***
 * The user is responsible for implementing a function of type
 * ZSTD_sequenceProducer_F. For each block, zstd will pass the following
 * arguments to the user-provided function:
 *
 *   - sequenceProducerState: a pointer to a user-managed state for the sequence
 *     producer.
 *
 *   - outSeqs, outSeqsCapacity: an output buffer for the sequence producer.
 *     outSeqsCapacity is guaranteed >= ZSTD_sequenceBound(srcSize). The memory
 *     backing outSeqs is managed by the CCtx.
 *
 *   - src, srcSize: an input buffer for the sequence producer to parse.
 *     srcSize is guaranteed to be <= ZSTD_BLOCKSIZE_MAX.
 *
 *   - dict, dictSize: a history buffer, which may be empty, which the sequence
 *     producer may reference as it parses the src buffer. Currently, zstd will
 *     always pass dictSize == 0 into external sequence producers, but this will
 *     change in the future.
 *
 *   - compressionLevel: a signed integer representing the zstd compression level
 *     set by the user for the current operation. The sequence producer may choose
 *     to use this information to change its compression strategy and speed/ratio
 *     tradeoff. Note: the compression level does not reflect zstd parameters set
 *     through the advanced API.
 *
 *   - windowSize: a size_t representing the maximum allowed offset for external
 *     sequences. Note that sequence offsets are sometimes allowed to exceed the
 *     windowSize if a dictionary is present, see doc/zstd_compression_format.md
 *     for details.
 *
 * The user-provided function shall return a size_t representing the number of
 * sequences written to outSeqs. This return value will be treated as an error
 * code if it is greater than outSeqsCapacity. The return value must be non-zero
 * if srcSize is non-zero. The ZSTD_SEQUENCE_PRODUCER_ERROR macro is provided
 * for convenience, but any value greater than outSeqsCapacity will be treated as
 * an error code.
 *
 * If the user-provided function does not return an error code, the sequences
 * written to outSeqs must be a valid parse of the src buffer. Data corruption may
 * occur if the parse is not valid. A parse is defined to be valid if the
 * following conditions hold:
 *   - The sum of matchLengths and literalLengths must equal srcSize.
 *   - All sequences in the parse, except for the final sequence, must have
 *     matchLength >= ZSTD_MINMATCH_MIN. The final sequence must have
 *     matchLength >= ZSTD_MINMATCH_MIN or matchLength == 0.
 *   - All offsets must respect the windowSize parameter as specified in
 *     doc/zstd_compression_format.md.
 *   - If the final sequence has matchLength == 0, it must also have offset == 0.
 *
 * zstd will only validate these conditions (and fail compression if they do not
 * hold) if the ZSTD_c_validateSequences cParam is enabled. Note that sequence
 * validation has a performance cost.
 *
 * If the user-provided function returns an error, zstd will either fall back
 * to an internal sequence producer or fail the compression operation. The user can
 * choose between the two behaviors by setting the ZSTD_c_enableSeqProducerFallback
 * cParam. Fallback compression will follow any other cParam settings, such as
 * compression level, the same as in a normal compression operation.
 *
 * The user shall instruct zstd to use a particular ZSTD_sequenceProducer_F
 * function by calling
 *         ZSTD_registerSequenceProducer(cctx,
 *                                       sequenceProducerState,
 *                                       sequenceProducer)
 * This setting will persist until the next parameter reset of the CCtx.
 *
 * The sequenceProducerState must be initialized by the user before calling
 * ZSTD_registerSequenceProducer(). The user is responsible for destroying the
 * sequenceProducerState.
 *
 * *** LIMITATIONS ***
 * This API is compatible with all zstd compression APIs which respect advanced parameters.
 * However, there are three limitations:
 *
 * First, the ZSTD_c_enableLongDistanceMatching cParam is not currently supported.
 * COMPRESSION WILL FAIL if it is enabled and the user tries to compress with a block-level
 * external sequence producer.
 *   - Note that ZSTD_c_enableLongDistanceMatching is auto-enabled by default in some
 *     cases (see its documentation for details). Users must explicitly set
 *     ZSTD_c_enableLongDistanceMatching to ZSTD_ps_disable in such cases if an external
 *     sequence producer is registered.
 *   - As of this writing, ZSTD_c_enableLongDistanceMatching is disabled by default
 *     whenever ZSTD_c_windowLog < 128MB, but that's subject to change. Users should
 *     check the docs on ZSTD_c_enableLongDistanceMatching whenever the Block-Level Sequence
 *     Producer API is used in conjunction with advanced settings (like ZSTD_c_windowLog).
 *
 * Second, history buffers are not currently supported. Concretely, zstd will always pass
 * dictSize == 0 to the external sequence producer (for now). This has two implications:
 *   - Dictionaries are not currently supported. Compression will *not* fail if the user
 *     references a dictionary, but the dictionary won't have any effect.
 *   - Stream history is not currently supported. All advanced compression APIs, including
 *     streaming APIs, work with external sequence producers, but each block is treated as
 *     an independent chunk without history from previous blocks.
 *
 * Third, multi-threading within a single compression is not currently supported. In other words,
 * COMPRESSION WILL FAIL if ZSTD_c_nbWorkers > 0 and an external sequence producer is registered.
 * Multi-threading across compressions is fine: simply create one CCtx per thread.
 *
 * Long-term, we plan to overcome all three limitations. There is no technical blocker to
 * overcoming them. It is purely a question of engineering effort.
 */

#define ZSTD_SEQUENCE_PRODUCER_ERROR ((size_t)(-1))

typedef size_t (*ZSTD_sequenceProducer_F) (
  void* sequenceProducerState,
  ZSTD_Sequence* outSeqs, size_t outSeqsCapacity,
  const void* src, size_t srcSize,
  const void* dict, size_t dictSize,
  int compressionLevel,
  size_t windowSize
);

/*! ZSTD_registerSequenceProducer() :
 * Instruct zstd to use a block-level external sequence producer function.
 *
 * The sequenceProducerState must be initialized by the caller, and the caller is
 * responsible for managing its lifetime. This parameter is sticky across
 * compressions. It will remain set until the user explicitly resets compression
 * parameters.
 *
 * Sequence producer registration is considered to be an "advanced parameter",
 * part of the "advanced API". This means it will only have an effect on compression
 * APIs which respect advanced parameters, such as compress2() and compressStream2().
 * Older compression APIs such as compressCCtx(), which predate the introduction of
 * "advanced parameters", will ignore any external sequence producer setting.
 *
 * The sequence producer can be "cleared" by registering a NULL function pointer. This
 * removes all limitations described above in the "LIMITATIONS" section of the API docs.
 *
 * The user is strongly encouraged to read the full API documentation (above) before
 * calling this function. */
ZSTDLIB_STATIC_API void
ZSTD_registerSequenceProducer(
  ZSTD_CCtx* cctx,
  void* sequenceProducerState,
  ZSTD_sequenceProducer_F sequenceProducer
);

/*! ZSTD_CCtxParams_registerSequenceProducer() :
 * Same as ZSTD_registerSequenceProducer(), but operates on ZSTD_CCtx_params.
 * This is used for accurate size estimation with ZSTD_estimateCCtxSize_usingCCtxParams(),
 * which is needed when creating a ZSTD_CCtx with ZSTD_initStaticCCtx().
 *
 * If you are using the external sequence producer API in a scenario where ZSTD_initStaticCCtx()
 * is required, then this function is for you. Otherwise, you probably don't need it.
 *
 * See tests/zstreamtest.c for example usage. */
ZSTDLIB_STATIC_API void
ZSTD_CCtxParams_registerSequenceProducer(
  ZSTD_CCtx_params* params,
  void* sequenceProducerState,
  ZSTD_sequenceProducer_F sequenceProducer
);


/*********************************************************************
*  Buffer-less and synchronous inner streaming functions (DEPRECATED)
*
*  This API is deprecated, and will be removed in a future version.
*  It allows streaming (de)compression with user allocated buffers.
*  However, it is hard to use, and not as well tested as the rest of
*  our API.
*
*  Please use the normal streaming API instead: ZSTD_compressStream2,
*  and ZSTD_decompressStream.
*  If there is functionality that you need, but it doesn't provide,
*  please open an issue on our GitHub.
********************************************************************* */

/**
  Buffer-less streaming compression (synchronous mode)

  A ZSTD_CCtx object is required to track streaming operations.
  Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource.
  ZSTD_CCtx object can be reused multiple times within successive compression operations.

  Start by initializing a context.
  Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression.

  Then, consume your input using ZSTD_compressContinue().
  There are some important considerations to keep in mind when using this advanced function :
  - ZSTD_compressContinue() has no internal buffer. It uses externally provided buffers only.
  - Interface is synchronous : input is consumed entirely and produces 1+ compressed blocks.
  - Caller must ensure there is enough space in `dst` to store compressed data under worst case scenario.
    Worst case evaluation is provided by ZSTD_compressBound().
    ZSTD_compressContinue() doesn't guarantee recover after a failed compression.
  - ZSTD_compressContinue() presumes prior input ***is still accessible and unmodified*** (up to maximum distance size, see WindowLog).
    It remembers all previous contiguous blocks, plus one separated memory segment (which can itself consists of multiple contiguous blocks)
  - ZSTD_compressContinue() detects that prior input has been overwritten when `src` buffer overlaps.
    In which case, it will "discard" the relevant memory section from its history.

  Finish a frame with ZSTD_compressEnd(), which will write the last block(s) and optional checksum.
  It's possible to use srcSize==0, in which case, it will write a final empty block to end the frame.
  Without last block mark, frames are considered unfinished (hence corrupted) by compliant decoders.

  `ZSTD_CCtx` object can be reused (ZSTD_compressBegin()) to compress again.
*/

/*=====   Buffer-less streaming compression functions  =====*/
ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); /**< note: fails if cdict==NULL */

ZSTD_DEPRECATED("This function will likely be removed in a future release. It is misleading and has very limited utility.")
ZSTDLIB_STATIC_API
size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**<  note: if pledgedSrcSize is not known, use ZSTD_CONTENTSIZE_UNKNOWN */

ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
ZSTD_DEPRECATED("The buffer-less API is deprecated in favor of the normal streaming API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);

/* The ZSTD_compressBegin_advanced() and ZSTD_compressBegin_usingCDict_advanced() are now DEPRECATED and will generate a compiler warning */
ZSTD_DEPRECATED("use advanced API to access custom parameters")
ZSTDLIB_STATIC_API
size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize : If srcSize is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN */
ZSTD_DEPRECATED("use advanced API to access custom parameters")
ZSTDLIB_STATIC_API
size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict, ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize);   /* compression parameters are already set within cdict. pledgedSrcSize must be correct. If srcSize is not known, use macro ZSTD_CONTENTSIZE_UNKNOWN */
/**
  Buffer-less streaming decompression (synchronous mode)

  A ZSTD_DCtx object is required to track streaming operations.
  Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
  A ZSTD_DCtx object can be reused multiple times.

  First typical operation is to retrieve frame parameters, using ZSTD_getFrameHeader().
  Frame header is extracted from the beginning of compressed frame, so providing only the frame's beginning is enough.
  Data fragment must be large enough to ensure successful decoding.
 `ZSTD_frameHeaderSize_max` bytes is guaranteed to always be large enough.
  result  : 0 : successful decoding, the `ZSTD_frameHeader` structure is correctly filled.
           >0 : `srcSize` is too small, please provide at least result bytes on next attempt.
           errorCode, which can be tested using ZSTD_isError().

  It fills a ZSTD_frameHeader structure with important information to correctly decode the frame,
  such as the dictionary ID, content size, or maximum back-reference distance (`windowSize`).
  Note that these values could be wrong, either because of data corruption, or because a 3rd party deliberately spoofs false information.
  As a consequence, check that values remain within valid application range.
  For example, do not allocate memory blindly, check that `windowSize` is within expectation.
  Each application can set its own limits, depending on local restrictions.
  For extended interoperability, it is recommended to support `windowSize` of at least 8 MB.

  ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize` bytes.
  ZSTD_decompressContinue() is very sensitive to contiguity,
  if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
  or that previous contiguous segment is large enough to properly handle maximum back-reference distance.
  There are multiple ways to guarantee this condition.

  The most memory efficient way is to use a round buffer of sufficient size.
  Sufficient size is determined by invoking ZSTD_decodingBufferSize_min(),
  which can return an error code if required value is too large for current system (in 32-bits mode).
  In a round buffer methodology, ZSTD_decompressContinue() decompresses each block next to previous one,
  up to the moment there is not enough room left in the buffer to guarantee decoding another full block,
  which maximum size is provided in `ZSTD_frameHeader` structure, field `blockSizeMax`.
  At which point, decoding can resume from the beginning of the buffer.
  Note that already decoded data stored in the buffer should be flushed before being overwritten.

  There are alternatives possible, for example using two or more buffers of size `windowSize` each, though they consume more memory.

  Finally, if you control the compression process, you can also ignore all buffer size rules,
  as long as the encoder and decoder progress in "lock-step",
  aka use exactly the same buffer sizes, break contiguity at the same place, etc.

  Once buffers are setup, start decompression, with ZSTD_decompressBegin().
  If decompression requires a dictionary, use ZSTD_decompressBegin_usingDict() or ZSTD_decompressBegin_usingDDict().

  Then use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
  ZSTD_nextSrcSizeToDecompress() tells how many bytes to provide as 'srcSize' to ZSTD_decompressContinue().
  ZSTD_decompressContinue() requires this _exact_ amount of bytes, or it will fail.

  result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
  It can be zero : it just means ZSTD_decompressContinue() has decoded some metadata item.
  It can also be an error code, which can be tested with ZSTD_isError().

  A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
  Context can then be reset to start a new decompression.

  Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
  This information is not required to properly decode a frame.

  == Special case : skippable frames ==

  Skippable frames allow integration of user-defined data into a flow of concatenated frames.
  Skippable frames will be ignored (skipped) by decompressor.
  The format of skippable frames is as follows :
  a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
  b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
  c) Frame Content - any content (User Data) of length equal to Frame Size
  For skippable frames ZSTD_getFrameHeader() returns zfhPtr->frameType==ZSTD_skippableFrame.
  For skippable frames ZSTD_decompressContinue() always returns 0 : it only skips the content.
*/

/*=====   Buffer-less streaming decompression functions  =====*/

ZSTDLIB_STATIC_API size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize);  /**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */

ZSTDLIB_STATIC_API size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
ZSTDLIB_STATIC_API size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
ZSTDLIB_STATIC_API size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);

ZSTDLIB_STATIC_API size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
ZSTDLIB_STATIC_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);

/* misc */
ZSTD_DEPRECATED("This function will likely be removed in the next minor release. It is misleading and has very limited utility.")
ZSTDLIB_STATIC_API void   ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
ZSTDLIB_STATIC_API ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);




/* ========================================= */
/**       Block level API (DEPRECATED)       */
/* ========================================= */

/*!

    This API is deprecated in favor of the regular compression API.
    You can get the frame header down to 2 bytes by setting:
      - ZSTD_c_format = ZSTD_f_zstd1_magicless
      - ZSTD_c_contentSizeFlag = 0
      - ZSTD_c_checksumFlag = 0
      - ZSTD_c_dictIDFlag = 0

    This API is not as well tested as our normal API, so we recommend not using it.
    We will be removing it in a future version. If the normal API doesn't provide
    the functionality you need, please open a GitHub issue.

    Block functions produce and decode raw zstd blocks, without frame metadata.
    Frame metadata cost is typically ~12 bytes, which can be non-negligible for very small blocks (< 100 bytes).
    But users will have to take in charge needed metadata to regenerate data, such as compressed and content sizes.

    A few rules to respect :
    - Compressing and decompressing require a context structure
      + Use ZSTD_createCCtx() and ZSTD_createDCtx()
    - It is necessary to init context before starting
      + compression : any ZSTD_compressBegin*() variant, including with dictionary
      + decompression : any ZSTD_decompressBegin*() variant, including with dictionary
    - Block size is limited, it must be <= ZSTD_getBlockSize() <= ZSTD_BLOCKSIZE_MAX == 128 KB
      + If input is larger than a block size, it's necessary to split input data into multiple blocks
      + For inputs larger than a single block, consider using regular ZSTD_compress() instead.
        Frame metadata is not that costly, and quickly becomes negligible as source size grows larger than a block.
    - When a block is considered not compressible enough, ZSTD_compressBlock() result will be 0 (zero) !
      ===> In which case, nothing is produced into `dst` !
      + User __must__ test for such outcome and deal directly with uncompressed data
      + A block cannot be declared incompressible if ZSTD_compressBlock() return value was != 0.
        Doing so would mess up with statistics history, leading to potential data corruption.
      + ZSTD_decompressBlock() _doesn't accept uncompressed data as input_ !!
      + In case of multiple successive blocks, should some of them be uncompressed,
        decoder must be informed of their existence in order to follow proper history.
        Use ZSTD_insertBlock() for such a case.
*/

/*=====   Raw zstd block functions  =====*/
ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_getBlockSize   (const ZSTD_CCtx* cctx);
ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_compressBlock  (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
ZSTD_DEPRECATED("The block API is deprecated in favor of the normal compression API. See docs.")
ZSTDLIB_STATIC_API size_t ZSTD_insertBlock    (ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize);  /**< insert uncompressed block into `dctx` history. Useful for multi-blocks decompression. */

#endif   /* ZSTD_H_ZSTD_STATIC_LINKING_ONLY */

#if defined (__cplusplus)
}
#endif
/**** ended inlining ../zstd.h ****/
#define FSE_STATIC_LINKING_ONLY
/**** skipping file: fse.h ****/
/**** skipping file: huf.h ****/
#ifndef XXH_STATIC_LINKING_ONLY
#  define XXH_STATIC_LINKING_ONLY  /* XXH64_state_t */
#endif
/**** start inlining xxhash.h ****/
/*
 * xxHash - Extremely Fast Hash algorithm
 * Header File
 * Copyright (c) Yann Collet - Meta Platforms, Inc
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* Local adaptations for Zstandard */

#ifndef XXH_NO_XXH3
# define XXH_NO_XXH3
#endif

#ifndef XXH_NAMESPACE
# define XXH_NAMESPACE ZSTD_
#endif

/*!
 * @mainpage xxHash
 *
 * xxHash is an extremely fast non-cryptographic hash algorithm, working at RAM speed
 * limits.
 *
 * It is proposed in four flavors, in three families:
 * 1. @ref XXH32_family
 *   - Classic 32-bit hash function. Simple, compact, and runs on almost all
 *     32-bit and 64-bit systems.
 * 2. @ref XXH64_family
 *   - Classic 64-bit adaptation of XXH32. Just as simple, and runs well on most
 *     64-bit systems (but _not_ 32-bit systems).
 * 3. @ref XXH3_family
 *   - Modern 64-bit and 128-bit hash function family which features improved
 *     strength and performance across the board, especially on smaller data.
 *     It benefits greatly from SIMD and 64-bit without requiring it.
 *
 * Benchmarks
 * ---
 * The reference system uses an Intel i7-9700K CPU, and runs Ubuntu x64 20.04.
 * The open source benchmark program is compiled with clang v10.0 using -O3 flag.
 *
 * | Hash Name            | ISA ext | Width | Large Data Speed | Small Data Velocity |
 * | -------------------- | ------- | ----: | ---------------: | ------------------: |
 * | XXH3_64bits()        | @b AVX2 |    64 |        59.4 GB/s |               133.1 |
 * | MeowHash             | AES-NI  |   128 |        58.2 GB/s |                52.5 |
 * | XXH3_128bits()       | @b AVX2 |   128 |        57.9 GB/s |               118.1 |
 * | CLHash               | PCLMUL  |    64 |        37.1 GB/s |                58.1 |
 * | XXH3_64bits()        | @b SSE2 |    64 |        31.5 GB/s |               133.1 |
 * | XXH3_128bits()       | @b SSE2 |   128 |        29.6 GB/s |               118.1 |
 * | RAM sequential read  |         |   N/A |        28.0 GB/s |                 N/A |
 * | ahash                | AES-NI  |    64 |        22.5 GB/s |               107.2 |
 * | City64               |         |    64 |        22.0 GB/s |                76.6 |
 * | T1ha2                |         |    64 |        22.0 GB/s |                99.0 |
 * | City128              |         |   128 |        21.7 GB/s |                57.7 |
 * | FarmHash             | AES-NI  |    64 |        21.3 GB/s |                71.9 |
 * | XXH64()              |         |    64 |        19.4 GB/s |                71.0 |
 * | SpookyHash           |         |    64 |        19.3 GB/s |                53.2 |
 * | Mum                  |         |    64 |        18.0 GB/s |                67.0 |
 * | CRC32C               | SSE4.2  |    32 |        13.0 GB/s |                57.9 |
 * | XXH32()              |         |    32 |         9.7 GB/s |                71.9 |
 * | City32               |         |    32 |         9.1 GB/s |                66.0 |
 * | Blake3*              | @b AVX2 |   256 |         4.4 GB/s |                 8.1 |
 * | Murmur3              |         |    32 |         3.9 GB/s |                56.1 |
 * | SipHash*             |         |    64 |         3.0 GB/s |                43.2 |
 * | Blake3*              | @b SSE2 |   256 |         2.4 GB/s |                 8.1 |
 * | HighwayHash          |         |    64 |         1.4 GB/s |                 6.0 |
 * | FNV64                |         |    64 |         1.2 GB/s |                62.7 |
 * | Blake2*              |         |   256 |         1.1 GB/s |                 5.1 |
 * | SHA1*                |         |   160 |         0.8 GB/s |                 5.6 |
 * | MD5*                 |         |   128 |         0.6 GB/s |                 7.8 |
 * @note
 *   - Hashes which require a specific ISA extension are noted. SSE2 is also noted,
 *     even though it is mandatory on x64.
 *   - Hashes with an asterisk are cryptographic. Note that MD5 is non-cryptographic
 *     by modern standards.
 *   - Small data velocity is a rough average of algorithm's efficiency for small
 *     data. For more accurate information, see the wiki.
 *   - More benchmarks and strength tests are found on the wiki:
 *         https://github.com/Cyan4973/xxHash/wiki
 *
 * Usage
 * ------
 * All xxHash variants use a similar API. Changing the algorithm is a trivial
 * substitution.
 *
 * @pre
 *    For functions which take an input and length parameter, the following
 *    requirements are assumed:
 *    - The range from [`input`, `input + length`) is valid, readable memory.
 *      - The only exception is if the `length` is `0`, `input` may be `NULL`.
 *    - For C++, the objects must have the *TriviallyCopyable* property, as the
 *      functions access bytes directly as if it was an array of `unsigned char`.
 *
 * @anchor single_shot_example
 * **Single Shot**
 *
 * These functions are stateless functions which hash a contiguous block of memory,
 * immediately returning the result. They are the easiest and usually the fastest
 * option.
 *
 * XXH32(), XXH64(), XXH3_64bits(), XXH3_128bits()
 *
 * @code{.c}
 *   #include <string.h>
 *   #include "xxhash.h"
 *
 *   // Example for a function which hashes a null terminated string with XXH32().
 *   XXH32_hash_t hash_string(const char* string, XXH32_hash_t seed)
 *   {
 *       // NULL pointers are only valid if the length is zero
 *       size_t length = (string == NULL) ? 0 : strlen(string);
 *       return XXH32(string, length, seed);
 *   }
 * @endcode
 *
 *
 * @anchor streaming_example
 * **Streaming**
 *
 * These groups of functions allow incremental hashing of unknown size, even
 * more than what would fit in a size_t.
 *
 * XXH32_reset(), XXH64_reset(), XXH3_64bits_reset(), XXH3_128bits_reset()
 *
 * @code{.c}
 *   #include <stdio.h>
 *   #include <assert.h>
 *   #include "xxhash.h"
 *   // Example for a function which hashes a FILE incrementally with XXH3_64bits().
 *   XXH64_hash_t hashFile(FILE* f)
 *   {
 *       // Allocate a state struct. Do not just use malloc() or new.
 *       XXH3_state_t* state = XXH3_createState();
 *       assert(state != NULL && "Out of memory!");
 *       // Reset the state to start a new hashing session.
 *       XXH3_64bits_reset(state);
 *       char buffer[4096];
 *       size_t count;
 *       // Read the file in chunks
 *       while ((count = fread(buffer, 1, sizeof(buffer), f)) != 0) {
 *           // Run update() as many times as necessary to process the data
 *           XXH3_64bits_update(state, buffer, count);
 *       }
 *       // Retrieve the finalized hash. This will not change the state.
 *       XXH64_hash_t result = XXH3_64bits_digest(state);
 *       // Free the state. Do not use free().
 *       XXH3_freeState(state);
 *       return result;
 *   }
 * @endcode
 *
 * Streaming functions generate the xxHash value from an incremental input.
 * This method is slower than single-call functions, due to state management.
 * For small inputs, prefer `XXH32()` and `XXH64()`, which are better optimized.
 *
 * An XXH state must first be allocated using `XXH*_createState()`.
 *
 * Start a new hash by initializing the state with a seed using `XXH*_reset()`.
 *
 * Then, feed the hash state by calling `XXH*_update()` as many times as necessary.
 *
 * The function returns an error code, with 0 meaning OK, and any other value
 * meaning there is an error.
 *
 * Finally, a hash value can be produced anytime, by using `XXH*_digest()`.
 * This function returns the nn-bits hash as an int or long long.
 *
 * It's still possible to continue inserting input into the hash state after a
 * digest, and generate new hash values later on by invoking `XXH*_digest()`.
 *
 * When done, release the state using `XXH*_freeState()`.
 *
 *
 * @anchor canonical_representation_example
 * **Canonical Representation**
 *
 * The default return values from XXH functions are unsigned 32, 64 and 128 bit
 * integers.
 * This the simplest and fastest format for further post-processing.
 *
 * However, this leaves open the question of what is the order on the byte level,
 * since little and big endian conventions will store the same number differently.
 *
 * The canonical representation settles this issue by mandating big-endian
 * convention, the same convention as human-readable numbers (large digits first).
 *
 * When writing hash values to storage, sending them over a network, or printing
 * them, it's highly recommended to use the canonical representation to ensure
 * portability across a wider range of systems, present and future.
 *
 * The following functions allow transformation of hash values to and from
 * canonical format.
 *
 * XXH32_canonicalFromHash(), XXH32_hashFromCanonical(),
 * XXH64_canonicalFromHash(), XXH64_hashFromCanonical(),
 * XXH128_canonicalFromHash(), XXH128_hashFromCanonical(),
 *
 * @code{.c}
 *   #include <stdio.h>
 *   #include "xxhash.h"
 *
 *   // Example for a function which prints XXH32_hash_t in human readable format
 *   void printXxh32(XXH32_hash_t hash)
 *   {
 *       XXH32_canonical_t cano;
 *       XXH32_canonicalFromHash(&cano, hash);
 *       size_t i;
 *       for(i = 0; i < sizeof(cano.digest); ++i) {
 *           printf("%02x", cano.digest[i]);
 *       }
 *       printf("\n");
 *   }
 *
 *   // Example for a function which converts XXH32_canonical_t to XXH32_hash_t
 *   XXH32_hash_t convertCanonicalToXxh32(XXH32_canonical_t cano)
 *   {
 *       XXH32_hash_t hash = XXH32_hashFromCanonical(&cano);
 *       return hash;
 *   }
 * @endcode
 *
 *
 * @file xxhash.h
 * xxHash prototypes and implementation
 */

#if defined (__cplusplus)
extern "C" {
#endif

/* ****************************
 *  INLINE mode
 ******************************/
/*!
 * @defgroup public Public API
 * Contains details on the public xxHash functions.
 * @{
 */
#ifdef XXH_DOXYGEN
/*!
 * @brief Gives access to internal state declaration, required for static allocation.
 *
 * Incompatible with dynamic linking, due to risks of ABI changes.
 *
 * Usage:
 * @code{.c}
 *     #define XXH_STATIC_LINKING_ONLY
 *     #include "xxhash.h"
 * @endcode
 */
#  define XXH_STATIC_LINKING_ONLY
/* Do not undef XXH_STATIC_LINKING_ONLY for Doxygen */

/*!
 * @brief Gives access to internal definitions.
 *
 * Usage:
 * @code{.c}
 *     #define XXH_STATIC_LINKING_ONLY
 *     #define XXH_IMPLEMENTATION
 *     #include "xxhash.h"
 * @endcode
 */
#  define XXH_IMPLEMENTATION
/* Do not undef XXH_IMPLEMENTATION for Doxygen */

/*!
 * @brief Exposes the implementation and marks all functions as `inline`.
 *
 * Use these build macros to inline xxhash into the target unit.
 * Inlining improves performance on small inputs, especially when the length is
 * expressed as a compile-time constant:
 *
 *  https://fastcompression.blogspot.com/2018/03/xxhash-for-small-keys-impressive-power.html
 *
 * It also keeps xxHash symbols private to the unit, so they are not exported.
 *
 * Usage:
 * @code{.c}
 *     #define XXH_INLINE_ALL
 *     #include "xxhash.h"
 * @endcode
 * Do not compile and link xxhash.o as a separate object, as it is not useful.
 */
#  define XXH_INLINE_ALL
#  undef XXH_INLINE_ALL
/*!
 * @brief Exposes the implementation without marking functions as inline.
 */
#  define XXH_PRIVATE_API
#  undef XXH_PRIVATE_API
/*!
 * @brief Emulate a namespace by transparently prefixing all symbols.
 *
 * If you want to include _and expose_ xxHash functions from within your own
 * library, but also want to avoid symbol collisions with other libraries which
 * may also include xxHash, you can use @ref XXH_NAMESPACE to automatically prefix
 * any public symbol from xxhash library with the value of @ref XXH_NAMESPACE
 * (therefore, avoid empty or numeric values).
 *
 * Note that no change is required within the calling program as long as it
 * includes `xxhash.h`: Regular symbol names will be automatically translated
 * by this header.
 */
#  define XXH_NAMESPACE /* YOUR NAME HERE */
#  undef XXH_NAMESPACE
#endif

#if (defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)) \
    && !defined(XXH_INLINE_ALL_31684351384)
   /* this section should be traversed only once */
#  define XXH_INLINE_ALL_31684351384
   /* give access to the advanced API, required to compile implementations */
#  undef XXH_STATIC_LINKING_ONLY   /* avoid macro redef */
#  define XXH_STATIC_LINKING_ONLY
   /* make all functions private */
#  undef XXH_PUBLIC_API
#  if defined(__GNUC__)
#    define XXH_PUBLIC_API static __inline __attribute__((unused))
#  elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#    define XXH_PUBLIC_API static inline
#  elif defined(_MSC_VER)
#    define XXH_PUBLIC_API static __inline
#  else
     /* note: this version may generate warnings for unused static functions */
#    define XXH_PUBLIC_API static
#  endif

   /*
    * This part deals with the special case where a unit wants to inline xxHash,
    * but "xxhash.h" has previously been included without XXH_INLINE_ALL,
    * such as part of some previously included *.h header file.
    * Without further action, the new include would just be ignored,
    * and functions would effectively _not_ be inlined (silent failure).
    * The following macros solve this situation by prefixing all inlined names,
    * avoiding naming collision with previous inclusions.
    */
   /* Before that, we unconditionally #undef all symbols,
    * in case they were already defined with XXH_NAMESPACE.
    * They will then be redefined for XXH_INLINE_ALL
    */
#  undef XXH_versionNumber
    /* XXH32 */
#  undef XXH32
#  undef XXH32_createState
#  undef XXH32_freeState
#  undef XXH32_reset
#  undef XXH32_update
#  undef XXH32_digest
#  undef XXH32_copyState
#  undef XXH32_canonicalFromHash
#  undef XXH32_hashFromCanonical
    /* XXH64 */
#  undef XXH64
#  undef XXH64_createState
#  undef XXH64_freeState
#  undef XXH64_reset
#  undef XXH64_update
#  undef XXH64_digest
#  undef XXH64_copyState
#  undef XXH64_canonicalFromHash
#  undef XXH64_hashFromCanonical
    /* XXH3_64bits */
#  undef XXH3_64bits
#  undef XXH3_64bits_withSecret
#  undef XXH3_64bits_withSeed
#  undef XXH3_64bits_withSecretandSeed
#  undef XXH3_createState
#  undef XXH3_freeState
#  undef XXH3_copyState
#  undef XXH3_64bits_reset
#  undef XXH3_64bits_reset_withSeed
#  undef XXH3_64bits_reset_withSecret
#  undef XXH3_64bits_update
#  undef XXH3_64bits_digest
#  undef XXH3_generateSecret
    /* XXH3_128bits */
#  undef XXH128
#  undef XXH3_128bits
#  undef XXH3_128bits_withSeed
#  undef XXH3_128bits_withSecret
#  undef XXH3_128bits_reset
#  undef XXH3_128bits_reset_withSeed
#  undef XXH3_128bits_reset_withSecret
#  undef XXH3_128bits_reset_withSecretandSeed
#  undef XXH3_128bits_update
#  undef XXH3_128bits_digest
#  undef XXH128_isEqual
#  undef XXH128_cmp
#  undef XXH128_canonicalFromHash
#  undef XXH128_hashFromCanonical
    /* Finally, free the namespace itself */
#  undef XXH_NAMESPACE

    /* employ the namespace for XXH_INLINE_ALL */
#  define XXH_NAMESPACE XXH_INLINE_
   /*
    * Some identifiers (enums, type names) are not symbols,
    * but they must nonetheless be renamed to avoid redeclaration.
    * Alternative solution: do not redeclare them.
    * However, this requires some #ifdefs, and has a more dispersed impact.
    * Meanwhile, renaming can be achieved in a single place.
    */
#  define XXH_IPREF(Id)   XXH_NAMESPACE ## Id
#  define XXH_OK XXH_IPREF(XXH_OK)
#  define XXH_ERROR XXH_IPREF(XXH_ERROR)
#  define XXH_errorcode XXH_IPREF(XXH_errorcode)
#  define XXH32_canonical_t  XXH_IPREF(XXH32_canonical_t)
#  define XXH64_canonical_t  XXH_IPREF(XXH64_canonical_t)
#  define XXH128_canonical_t XXH_IPREF(XXH128_canonical_t)
#  define XXH32_state_s XXH_IPREF(XXH32_state_s)
#  define XXH32_state_t XXH_IPREF(XXH32_state_t)
#  define XXH64_state_s XXH_IPREF(XXH64_state_s)
#  define XXH64_state_t XXH_IPREF(XXH64_state_t)
#  define XXH3_state_s  XXH_IPREF(XXH3_state_s)
#  define XXH3_state_t  XXH_IPREF(XXH3_state_t)
#  define XXH128_hash_t XXH_IPREF(XXH128_hash_t)
   /* Ensure the header is parsed again, even if it was previously included */
#  undef XXHASH_H_5627135585666179
#  undef XXHASH_H_STATIC_13879238742
#endif /* XXH_INLINE_ALL || XXH_PRIVATE_API */

/* ****************************************************************
 *  Stable API
 *****************************************************************/
#ifndef XXHASH_H_5627135585666179
#define XXHASH_H_5627135585666179 1

/*! @brief Marks a global symbol. */
#if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
#  if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
#    ifdef XXH_EXPORT
#      define XXH_PUBLIC_API __declspec(dllexport)
#    elif XXH_IMPORT
#      define XXH_PUBLIC_API __declspec(dllimport)
#    endif
#  else
#    define XXH_PUBLIC_API   /* do nothing */
#  endif
#endif

#ifdef XXH_NAMESPACE
#  define XXH_CAT(A,B) A##B
#  define XXH_NAME2(A,B) XXH_CAT(A,B)
#  define XXH_versionNumber XXH_NAME2(XXH_NAMESPACE, XXH_versionNumber)
/* XXH32 */
#  define XXH32 XXH_NAME2(XXH_NAMESPACE, XXH32)
#  define XXH32_createState XXH_NAME2(XXH_NAMESPACE, XXH32_createState)
#  define XXH32_freeState XXH_NAME2(XXH_NAMESPACE, XXH32_freeState)
#  define XXH32_reset XXH_NAME2(XXH_NAMESPACE, XXH32_reset)
#  define XXH32_update XXH_NAME2(XXH_NAMESPACE, XXH32_update)
#  define XXH32_digest XXH_NAME2(XXH_NAMESPACE, XXH32_digest)
#  define XXH32_copyState XXH_NAME2(XXH_NAMESPACE, XXH32_copyState)
#  define XXH32_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH32_canonicalFromHash)
#  define XXH32_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH32_hashFromCanonical)
/* XXH64 */
#  define XXH64 XXH_NAME2(XXH_NAMESPACE, XXH64)
#  define XXH64_createState XXH_NAME2(XXH_NAMESPACE, XXH64_createState)
#  define XXH64_freeState XXH_NAME2(XXH_NAMESPACE, XXH64_freeState)
#  define XXH64_reset XXH_NAME2(XXH_NAMESPACE, XXH64_reset)
#  define XXH64_update XXH_NAME2(XXH_NAMESPACE, XXH64_update)
#  define XXH64_digest XXH_NAME2(XXH_NAMESPACE, XXH64_digest)
#  define XXH64_copyState XXH_NAME2(XXH_NAMESPACE, XXH64_copyState)
#  define XXH64_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH64_canonicalFromHash)
#  define XXH64_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH64_hashFromCanonical)
/* XXH3_64bits */
#  define XXH3_64bits XXH_NAME2(XXH_NAMESPACE, XXH3_64bits)
#  define XXH3_64bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecret)
#  define XXH3_64bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSeed)
#  define XXH3_64bits_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_withSecretandSeed)
#  define XXH3_createState XXH_NAME2(XXH_NAMESPACE, XXH3_createState)
#  define XXH3_freeState XXH_NAME2(XXH_NAMESPACE, XXH3_freeState)
#  define XXH3_copyState XXH_NAME2(XXH_NAMESPACE, XXH3_copyState)
#  define XXH3_64bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset)
#  define XXH3_64bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSeed)
#  define XXH3_64bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecret)
#  define XXH3_64bits_reset_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_reset_withSecretandSeed)
#  define XXH3_64bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_update)
#  define XXH3_64bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_64bits_digest)
#  define XXH3_generateSecret XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret)
#  define XXH3_generateSecret_fromSeed XXH_NAME2(XXH_NAMESPACE, XXH3_generateSecret_fromSeed)
/* XXH3_128bits */
#  define XXH128 XXH_NAME2(XXH_NAMESPACE, XXH128)
#  define XXH3_128bits XXH_NAME2(XXH_NAMESPACE, XXH3_128bits)
#  define XXH3_128bits_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSeed)
#  define XXH3_128bits_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecret)
#  define XXH3_128bits_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_withSecretandSeed)
#  define XXH3_128bits_reset XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset)
#  define XXH3_128bits_reset_withSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSeed)
#  define XXH3_128bits_reset_withSecret XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecret)
#  define XXH3_128bits_reset_withSecretandSeed XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_reset_withSecretandSeed)
#  define XXH3_128bits_update XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_update)
#  define XXH3_128bits_digest XXH_NAME2(XXH_NAMESPACE, XXH3_128bits_digest)
#  define XXH128_isEqual XXH_NAME2(XXH_NAMESPACE, XXH128_isEqual)
#  define XXH128_cmp     XXH_NAME2(XXH_NAMESPACE, XXH128_cmp)
#  define XXH128_canonicalFromHash XXH_NAME2(XXH_NAMESPACE, XXH128_canonicalFromHash)
#  define XXH128_hashFromCanonical XXH_NAME2(XXH_NAMESPACE, XXH128_hashFromCanonical)
#endif


/* *************************************
*  Compiler specifics
***************************************/

/* specific declaration modes for Windows */
#if !defined(XXH_INLINE_ALL) && !defined(XXH_PRIVATE_API)
#  if defined(WIN32) && defined(_MSC_VER) && (defined(XXH_IMPORT) || defined(XXH_EXPORT))
#    ifdef XXH_EXPORT
#      define XXH_PUBLIC_API __declspec(dllexport)
#    elif XXH_IMPORT
#      define XXH_PUBLIC_API __declspec(dllimport)
#    endif
#  else
#    define XXH_PUBLIC_API   /* do nothing */
#  endif
#endif

#if defined (__GNUC__)
# define XXH_CONSTF  __attribute__((const))
# define XXH_PUREF   __attribute__((pure))
#else
# define XXH_CONSTF  /* disable */
# define XXH_PUREF
#endif

/* *************************************
*  Version
***************************************/
#define XXH_VERSION_MAJOR    0
#define XXH_VERSION_MINOR    8
#define XXH_VERSION_RELEASE  2
/*! @brief Version number, encoded as two digits each */
#define XXH_VERSION_NUMBER  (XXH_VERSION_MAJOR *100*100 + XXH_VERSION_MINOR *100 + XXH_VERSION_RELEASE)

/*!
 * @brief Obtains the xxHash version.
 *
 * This is mostly useful when xxHash is compiled as a shared library,
 * since the returned value comes from the library, as opposed to header file.
 *
 * @return @ref XXH_VERSION_NUMBER of the invoked library.
 */
XXH_PUBLIC_API XXH_CONSTF unsigned XXH_versionNumber (void);


/* ****************************
*  Common basic types
******************************/
#include <stddef.h>   /* size_t */
/*!
 * @brief Exit code for the streaming API.
 */
typedef enum {
    XXH_OK = 0, /*!< OK */
    XXH_ERROR   /*!< Error */
} XXH_errorcode;


/*-**********************************************************************
*  32-bit hash
************************************************************************/
#if defined(XXH_DOXYGEN) /* Don't show <stdint.h> include */
/*!
 * @brief An unsigned 32-bit integer.
 *
 * Not necessarily defined to `uint32_t` but functionally equivalent.
 */
typedef uint32_t XXH32_hash_t;

#elif !defined (__VMS) \
  && (defined (__cplusplus) \
  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
#   ifdef _AIX
#     include <inttypes.h>
#   else
#     include <stdint.h>
#   endif
    typedef uint32_t XXH32_hash_t;

#else
#   include <limits.h>
#   if UINT_MAX == 0xFFFFFFFFUL
      typedef unsigned int XXH32_hash_t;
#   elif ULONG_MAX == 0xFFFFFFFFUL
      typedef unsigned long XXH32_hash_t;
#   else
#     error "unsupported platform: need a 32-bit type"
#   endif
#endif

/*!
 * @}
 *
 * @defgroup XXH32_family XXH32 family
 * @ingroup public
 * Contains functions used in the classic 32-bit xxHash algorithm.
 *
 * @note
 *   XXH32 is useful for older platforms, with no or poor 64-bit performance.
 *   Note that the @ref XXH3_family provides competitive speed for both 32-bit
 *   and 64-bit systems, and offers true 64/128 bit hash results.
 *
 * @see @ref XXH64_family, @ref XXH3_family : Other xxHash families
 * @see @ref XXH32_impl for implementation details
 * @{
 */

/*!
 * @brief Calculates the 32-bit hash of @p input using xxHash32.
 *
 * @param input The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 * @param seed The 32-bit seed to alter the hash's output predictably.
 *
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return The calculated 32-bit xxHash32 value.
 *
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH32_hash_t XXH32 (const void* input, size_t length, XXH32_hash_t seed);

#ifndef XXH_NO_STREAM
/*!
 * @typedef struct XXH32_state_s XXH32_state_t
 * @brief The opaque state struct for the XXH32 streaming API.
 *
 * @see XXH32_state_s for details.
 */
typedef struct XXH32_state_s XXH32_state_t;

/*!
 * @brief Allocates an @ref XXH32_state_t.
 *
 * @return An allocated pointer of @ref XXH32_state_t on success.
 * @return `NULL` on failure.
 *
 * @note Must be freed with XXH32_freeState().
 */
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void);
/*!
 * @brief Frees an @ref XXH32_state_t.
 *
 * @param statePtr A pointer to an @ref XXH32_state_t allocated with @ref XXH32_createState().
 *
 * @return @ref XXH_OK.
 *
 * @note @p statePtr must be allocated with XXH32_createState().
 *
 */
XXH_PUBLIC_API XXH_errorcode  XXH32_freeState(XXH32_state_t* statePtr);
/*!
 * @brief Copies one @ref XXH32_state_t to another.
 *
 * @param dst_state The state to copy to.
 * @param src_state The state to copy from.
 * @pre
 *   @p dst_state and @p src_state must not be `NULL` and must not overlap.
 */
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dst_state, const XXH32_state_t* src_state);

/*!
 * @brief Resets an @ref XXH32_state_t to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 * @param seed The 32-bit seed to alter the hash result predictably.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note This function resets and seeds a state. Call it before @ref XXH32_update().
 */
XXH_PUBLIC_API XXH_errorcode XXH32_reset  (XXH32_state_t* statePtr, XXH32_hash_t seed);

/*!
 * @brief Consumes a block of @p input to an @ref XXH32_state_t.
 *
 * @param statePtr The state struct to update.
 * @param input The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note Call this to incrementally consume blocks of data.
 */
XXH_PUBLIC_API XXH_errorcode XXH32_update (XXH32_state_t* statePtr, const void* input, size_t length);

/*!
 * @brief Returns the calculated hash value from an @ref XXH32_state_t.
 *
 * @param statePtr The state struct to calculate the hash from.
 *
 * @pre
 *  @p statePtr must not be `NULL`.
 *
 * @return The calculated 32-bit xxHash32 value from that state.
 *
 * @note
 *   Calling XXH32_digest() will not affect @p statePtr, so you can update,
 *   digest, and update again.
 */
XXH_PUBLIC_API XXH_PUREF XXH32_hash_t XXH32_digest (const XXH32_state_t* statePtr);
#endif /* !XXH_NO_STREAM */

/*******   Canonical representation   *******/

/*!
 * @brief Canonical (big endian) representation of @ref XXH32_hash_t.
 */
typedef struct {
    unsigned char digest[4]; /*!< Hash bytes, big endian */
} XXH32_canonical_t;

/*!
 * @brief Converts an @ref XXH32_hash_t to a big endian @ref XXH32_canonical_t.
 *
 * @param dst  The @ref XXH32_canonical_t pointer to be stored to.
 * @param hash The @ref XXH32_hash_t to be converted.
 *
 * @pre
 *   @p dst must not be `NULL`.
 *
 * @see @ref canonical_representation_example "Canonical Representation Example"
 */
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash);

/*!
 * @brief Converts an @ref XXH32_canonical_t to a native @ref XXH32_hash_t.
 *
 * @param src The @ref XXH32_canonical_t to convert.
 *
 * @pre
 *   @p src must not be `NULL`.
 *
 * @return The converted hash.
 *
 * @see @ref canonical_representation_example "Canonical Representation Example"
 */
XXH_PUBLIC_API XXH_PUREF XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src);


/*! @cond Doxygen ignores this part */
#ifdef __has_attribute
# define XXH_HAS_ATTRIBUTE(x) __has_attribute(x)
#else
# define XXH_HAS_ATTRIBUTE(x) 0
#endif
/*! @endcond */

/*! @cond Doxygen ignores this part */
/*
 * C23 __STDC_VERSION__ number hasn't been specified yet. For now
 * leave as `201711L` (C17 + 1).
 * TODO: Update to correct value when its been specified.
 */
#define XXH_C23_VN 201711L
/*! @endcond */

/*! @cond Doxygen ignores this part */
/* C-language Attributes are added in C23. */
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= XXH_C23_VN) && defined(__has_c_attribute)
# define XXH_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
#else
# define XXH_HAS_C_ATTRIBUTE(x) 0
#endif
/*! @endcond */

/*! @cond Doxygen ignores this part */
#if defined(__cplusplus) && defined(__has_cpp_attribute)
# define XXH_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
#else
# define XXH_HAS_CPP_ATTRIBUTE(x) 0
#endif
/*! @endcond */

/*! @cond Doxygen ignores this part */
/*
 * Define XXH_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute
 * introduced in CPP17 and C23.
 * CPP17 : https://en.cppreference.com/w/cpp/language/attributes/fallthrough
 * C23   : https://en.cppreference.com/w/c/language/attributes/fallthrough
 */
#if XXH_HAS_C_ATTRIBUTE(fallthrough) || XXH_HAS_CPP_ATTRIBUTE(fallthrough)
# define XXH_FALLTHROUGH [[fallthrough]]
#elif XXH_HAS_ATTRIBUTE(__fallthrough__)
# define XXH_FALLTHROUGH __attribute__ ((__fallthrough__))
#else
# define XXH_FALLTHROUGH /* fallthrough */
#endif
/*! @endcond */

/*! @cond Doxygen ignores this part */
/*
 * Define XXH_NOESCAPE for annotated pointers in public API.
 * https://clang.llvm.org/docs/AttributeReference.html#noescape
 * As of writing this, only supported by clang.
 */
#if XXH_HAS_ATTRIBUTE(noescape)
# define XXH_NOESCAPE __attribute__((noescape))
#else
# define XXH_NOESCAPE
#endif
/*! @endcond */


/*!
 * @}
 * @ingroup public
 * @{
 */

#ifndef XXH_NO_LONG_LONG
/*-**********************************************************************
*  64-bit hash
************************************************************************/
#if defined(XXH_DOXYGEN) /* don't include <stdint.h> */
/*!
 * @brief An unsigned 64-bit integer.
 *
 * Not necessarily defined to `uint64_t` but functionally equivalent.
 */
typedef uint64_t XXH64_hash_t;
#elif !defined (__VMS) \
  && (defined (__cplusplus) \
  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
#   ifdef _AIX
#     include <inttypes.h>
#   else
#     include <stdint.h>
#   endif
   typedef uint64_t XXH64_hash_t;
#else
#  include <limits.h>
#  if defined(__LP64__) && ULONG_MAX == 0xFFFFFFFFFFFFFFFFULL
     /* LP64 ABI says uint64_t is unsigned long */
     typedef unsigned long XXH64_hash_t;
#  else
     /* the following type must have a width of 64-bit */
     typedef unsigned long long XXH64_hash_t;
#  endif
#endif

/*!
 * @}
 *
 * @defgroup XXH64_family XXH64 family
 * @ingroup public
 * @{
 * Contains functions used in the classic 64-bit xxHash algorithm.
 *
 * @note
 *   XXH3 provides competitive speed for both 32-bit and 64-bit systems,
 *   and offers true 64/128 bit hash results.
 *   It provides better speed for systems with vector processing capabilities.
 */

/*!
 * @brief Calculates the 64-bit hash of @p input using xxHash64.
 *
 * @param input The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 * @param seed The 64-bit seed to alter the hash's output predictably.
 *
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return The calculated 64-bit xxHash64 value.
 *
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t XXH64(XXH_NOESCAPE const void* input, size_t length, XXH64_hash_t seed);

/*******   Streaming   *******/
#ifndef XXH_NO_STREAM
/*!
 * @brief The opaque state struct for the XXH64 streaming API.
 *
 * @see XXH64_state_s for details.
 */
typedef struct XXH64_state_s XXH64_state_t;   /* incomplete type */

/*!
 * @brief Allocates an @ref XXH64_state_t.
 *
 * @return An allocated pointer of @ref XXH64_state_t on success.
 * @return `NULL` on failure.
 *
 * @note Must be freed with XXH64_freeState().
 */
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void);

/*!
 * @brief Frees an @ref XXH64_state_t.
 *
 * @param statePtr A pointer to an @ref XXH64_state_t allocated with @ref XXH64_createState().
 *
 * @return @ref XXH_OK.
 *
 * @note @p statePtr must be allocated with XXH64_createState().
 */
XXH_PUBLIC_API XXH_errorcode  XXH64_freeState(XXH64_state_t* statePtr);

/*!
 * @brief Copies one @ref XXH64_state_t to another.
 *
 * @param dst_state The state to copy to.
 * @param src_state The state to copy from.
 * @pre
 *   @p dst_state and @p src_state must not be `NULL` and must not overlap.
 */
XXH_PUBLIC_API void XXH64_copyState(XXH_NOESCAPE XXH64_state_t* dst_state, const XXH64_state_t* src_state);

/*!
 * @brief Resets an @ref XXH64_state_t to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 * @param seed The 64-bit seed to alter the hash result predictably.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note This function resets and seeds a state. Call it before @ref XXH64_update().
 */
XXH_PUBLIC_API XXH_errorcode XXH64_reset  (XXH_NOESCAPE XXH64_state_t* statePtr, XXH64_hash_t seed);

/*!
 * @brief Consumes a block of @p input to an @ref XXH64_state_t.
 *
 * @param statePtr The state struct to update.
 * @param input The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note Call this to incrementally consume blocks of data.
 */
XXH_PUBLIC_API XXH_errorcode XXH64_update (XXH_NOESCAPE XXH64_state_t* statePtr, XXH_NOESCAPE const void* input, size_t length);

/*!
 * @brief Returns the calculated hash value from an @ref XXH64_state_t.
 *
 * @param statePtr The state struct to calculate the hash from.
 *
 * @pre
 *  @p statePtr must not be `NULL`.
 *
 * @return The calculated 64-bit xxHash64 value from that state.
 *
 * @note
 *   Calling XXH64_digest() will not affect @p statePtr, so you can update,
 *   digest, and update again.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t XXH64_digest (XXH_NOESCAPE const XXH64_state_t* statePtr);
#endif /* !XXH_NO_STREAM */
/*******   Canonical representation   *******/

/*!
 * @brief Canonical (big endian) representation of @ref XXH64_hash_t.
 */
typedef struct { unsigned char digest[sizeof(XXH64_hash_t)]; } XXH64_canonical_t;

/*!
 * @brief Converts an @ref XXH64_hash_t to a big endian @ref XXH64_canonical_t.
 *
 * @param dst The @ref XXH64_canonical_t pointer to be stored to.
 * @param hash The @ref XXH64_hash_t to be converted.
 *
 * @pre
 *   @p dst must not be `NULL`.
 *
 * @see @ref canonical_representation_example "Canonical Representation Example"
 */
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH_NOESCAPE XXH64_canonical_t* dst, XXH64_hash_t hash);

/*!
 * @brief Converts an @ref XXH64_canonical_t to a native @ref XXH64_hash_t.
 *
 * @param src The @ref XXH64_canonical_t to convert.
 *
 * @pre
 *   @p src must not be `NULL`.
 *
 * @return The converted hash.
 *
 * @see @ref canonical_representation_example "Canonical Representation Example"
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t XXH64_hashFromCanonical(XXH_NOESCAPE const XXH64_canonical_t* src);

#ifndef XXH_NO_XXH3

/*!
 * @}
 * ************************************************************************
 * @defgroup XXH3_family XXH3 family
 * @ingroup public
 * @{
 *
 * XXH3 is a more recent hash algorithm featuring:
 *  - Improved speed for both small and large inputs
 *  - True 64-bit and 128-bit outputs
 *  - SIMD acceleration
 *  - Improved 32-bit viability
 *
 * Speed analysis methodology is explained here:
 *
 *    https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html
 *
 * Compared to XXH64, expect XXH3 to run approximately
 * ~2x faster on large inputs and >3x faster on small ones,
 * exact differences vary depending on platform.
 *
 * XXH3's speed benefits greatly from SIMD and 64-bit arithmetic,
 * but does not require it.
 * Most 32-bit and 64-bit targets that can run XXH32 smoothly can run XXH3
 * at competitive speeds, even without vector support. Further details are
 * explained in the implementation.
 *
 * XXH3 has a fast scalar implementation, but it also includes accelerated SIMD
 * implementations for many common platforms:
 *   - AVX512
 *   - AVX2
 *   - SSE2
 *   - ARM NEON
 *   - WebAssembly SIMD128
 *   - POWER8 VSX
 *   - s390x ZVector
 * This can be controlled via the @ref XXH_VECTOR macro, but it automatically
 * selects the best version according to predefined macros. For the x86 family, an
 * automatic runtime dispatcher is included separately in @ref xxh_x86dispatch.c.
 *
 * XXH3 implementation is portable:
 * it has a generic C90 formulation that can be compiled on any platform,
 * all implementations generate exactly the same hash value on all platforms.
 * Starting from v0.8.0, it's also labelled "stable", meaning that
 * any future version will also generate the same hash value.
 *
 * XXH3 offers 2 variants, _64bits and _128bits.
 *
 * When only 64 bits are needed, prefer invoking the _64bits variant, as it
 * reduces the amount of mixing, resulting in faster speed on small inputs.
 * It's also generally simpler to manipulate a scalar return type than a struct.
 *
 * The API supports one-shot hashing, streaming mode, and custom secrets.
 */
/*-**********************************************************************
*  XXH3 64-bit variant
************************************************************************/

/*!
 * @brief Calculates 64-bit unseeded variant of XXH3 hash of @p input.
 *
 * @param input  The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 *
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return The calculated 64-bit XXH3 hash value.
 *
 * @note
 *   This is equivalent to @ref XXH3_64bits_withSeed() with a seed of `0`, however
 *   it may have slightly better performance due to constant propagation of the
 *   defaults.
 *
 * @see
 *    XXH3_64bits_withSeed(), XXH3_64bits_withSecret(): other seeding variants
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t XXH3_64bits(XXH_NOESCAPE const void* input, size_t length);

/*!
 * @brief Calculates 64-bit seeded variant of XXH3 hash of @p input.
 *
 * @param input  The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 * @param seed   The 64-bit seed to alter the hash result predictably.
 *
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return The calculated 64-bit XXH3 hash value.
 *
 * @note
 *    seed == 0 produces the same results as @ref XXH3_64bits().
 *
 * This variant generates a custom secret on the fly based on default secret
 * altered using the @p seed value.
 *
 * While this operation is decently fast, note that it's not completely free.
 *
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t XXH3_64bits_withSeed(XXH_NOESCAPE const void* input, size_t length, XXH64_hash_t seed);

/*!
 * The bare minimum size for a custom secret.
 *
 * @see
 *  XXH3_64bits_withSecret(), XXH3_64bits_reset_withSecret(),
 *  XXH3_128bits_withSecret(), XXH3_128bits_reset_withSecret().
 */
#define XXH3_SECRET_SIZE_MIN 136

/*!
 * @brief Calculates 64-bit variant of XXH3 with a custom "secret".
 *
 * @param data       The block of data to be hashed, at least @p len bytes in size.
 * @param len        The length of @p data, in bytes.
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 *
 * @return The calculated 64-bit XXH3 hash value.
 *
 * @pre
 *   The memory between @p data and @p data + @p len must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p data may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * It's possible to provide any blob of bytes as a "secret" to generate the hash.
 * This makes it more difficult for an external actor to prepare an intentional collision.
 * The main condition is that @p secretSize *must* be large enough (>= @ref XXH3_SECRET_SIZE_MIN).
 * However, the quality of the secret impacts the dispersion of the hash algorithm.
 * Therefore, the secret _must_ look like a bunch of random bytes.
 * Avoid "trivial" or structured data such as repeated sequences or a text document.
 * Whenever in doubt about the "randomness" of the blob of bytes,
 * consider employing @ref XXH3_generateSecret() instead (see below).
 * It will generate a proper high entropy secret derived from the blob of bytes.
 * Another advantage of using XXH3_generateSecret() is that
 * it guarantees that all bits within the initial blob of bytes
 * will impact every bit of the output.
 * This is not necessarily the case when using the blob of bytes directly
 * because, when hashing _small_ inputs, only a portion of the secret is employed.
 *
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t XXH3_64bits_withSecret(XXH_NOESCAPE const void* data, size_t len, XXH_NOESCAPE const void* secret, size_t secretSize);


/*******   Streaming   *******/
#ifndef XXH_NO_STREAM
/*
 * Streaming requires state maintenance.
 * This operation costs memory and CPU.
 * As a consequence, streaming is slower than one-shot hashing.
 * For better performance, prefer one-shot functions whenever applicable.
 */

/*!
 * @brief The opaque state struct for the XXH3 streaming API.
 *
 * @see XXH3_state_s for details.
 */
typedef struct XXH3_state_s XXH3_state_t;
XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void);
XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr);

/*!
 * @brief Copies one @ref XXH3_state_t to another.
 *
 * @param dst_state The state to copy to.
 * @param src_state The state to copy from.
 * @pre
 *   @p dst_state and @p src_state must not be `NULL` and must not overlap.
 */
XXH_PUBLIC_API void XXH3_copyState(XXH_NOESCAPE XXH3_state_t* dst_state, XXH_NOESCAPE const XXH3_state_t* src_state);

/*!
 * @brief Resets an @ref XXH3_state_t to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note
 *   - This function resets `statePtr` and generate a secret with default parameters.
 *   - Call this function before @ref XXH3_64bits_update().
 *   - Digest will be equivalent to `XXH3_64bits()`.
 *
 */
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset(XXH_NOESCAPE XXH3_state_t* statePtr);

/*!
 * @brief Resets an @ref XXH3_state_t with 64-bit seed to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 * @param seed     The 64-bit seed to alter the hash result predictably.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note
 *   - This function resets `statePtr` and generate a secret from `seed`.
 *   - Call this function before @ref XXH3_64bits_update().
 *   - Digest will be equivalent to `XXH3_64bits_withSeed()`.
 *
 */
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSeed(XXH_NOESCAPE XXH3_state_t* statePtr, XXH64_hash_t seed);

/*!
 * @brief Resets an @ref XXH3_state_t with secret data to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note
 *   `secret` is referenced, it _must outlive_ the hash streaming session.
 *
 * Similar to one-shot API, `secretSize` must be >= @ref XXH3_SECRET_SIZE_MIN,
 * and the quality of produced hash values depends on secret's entropy
 * (secret's content should look like a bunch of random bytes).
 * When in doubt about the randomness of a candidate `secret`,
 * consider employing `XXH3_generateSecret()` instead (see below).
 */
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_reset_withSecret(XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* secret, size_t secretSize);

/*!
 * @brief Consumes a block of @p input to an @ref XXH3_state_t.
 *
 * @param statePtr The state struct to update.
 * @param input The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 * @pre
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note Call this to incrementally consume blocks of data.
 */
XXH_PUBLIC_API XXH_errorcode XXH3_64bits_update (XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* input, size_t length);

/*!
 * @brief Returns the calculated XXH3 64-bit hash value from an @ref XXH3_state_t.
 *
 * @param statePtr The state struct to calculate the hash from.
 *
 * @pre
 *  @p statePtr must not be `NULL`.
 *
 * @return The calculated XXH3 64-bit hash value from that state.
 *
 * @note
 *   Calling XXH3_64bits_digest() will not affect @p statePtr, so you can update,
 *   digest, and update again.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t  XXH3_64bits_digest (XXH_NOESCAPE const XXH3_state_t* statePtr);
#endif /* !XXH_NO_STREAM */

/* note : canonical representation of XXH3 is the same as XXH64
 * since they both produce XXH64_hash_t values */


/*-**********************************************************************
*  XXH3 128-bit variant
************************************************************************/

/*!
 * @brief The return value from 128-bit hashes.
 *
 * Stored in little endian order, although the fields themselves are in native
 * endianness.
 */
typedef struct {
    XXH64_hash_t low64;   /*!< `value & 0xFFFFFFFFFFFFFFFF` */
    XXH64_hash_t high64;  /*!< `value >> 64` */
} XXH128_hash_t;

/*!
 * @brief Calculates 128-bit unseeded variant of XXH3 of @p data.
 *
 * @param data The block of data to be hashed, at least @p length bytes in size.
 * @param len  The length of @p data, in bytes.
 *
 * @return The calculated 128-bit variant of XXH3 value.
 *
 * The 128-bit variant of XXH3 has more strength, but it has a bit of overhead
 * for shorter inputs.
 *
 * This is equivalent to @ref XXH3_128bits_withSeed() with a seed of `0`, however
 * it may have slightly better performance due to constant propagation of the
 * defaults.
 *
 * @see XXH3_128bits_withSeed(), XXH3_128bits_withSecret(): other seeding variants
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH3_128bits(XXH_NOESCAPE const void* data, size_t len);
/*! @brief Calculates 128-bit seeded variant of XXH3 hash of @p data.
 *
 * @param data The block of data to be hashed, at least @p length bytes in size.
 * @param len  The length of @p data, in bytes.
 * @param seed The 64-bit seed to alter the hash result predictably.
 *
 * @return The calculated 128-bit variant of XXH3 value.
 *
 * @note
 *    seed == 0 produces the same results as @ref XXH3_64bits().
 *
 * This variant generates a custom secret on the fly based on default secret
 * altered using the @p seed value.
 *
 * While this operation is decently fast, note that it's not completely free.
 *
 * @see XXH3_128bits(), XXH3_128bits_withSecret(): other seeding variants
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH3_128bits_withSeed(XXH_NOESCAPE const void* data, size_t len, XXH64_hash_t seed);
/*!
 * @brief Calculates 128-bit variant of XXH3 with a custom "secret".
 *
 * @param data       The block of data to be hashed, at least @p len bytes in size.
 * @param len        The length of @p data, in bytes.
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 *
 * @return The calculated 128-bit variant of XXH3 value.
 *
 * It's possible to provide any blob of bytes as a "secret" to generate the hash.
 * This makes it more difficult for an external actor to prepare an intentional collision.
 * The main condition is that @p secretSize *must* be large enough (>= @ref XXH3_SECRET_SIZE_MIN).
 * However, the quality of the secret impacts the dispersion of the hash algorithm.
 * Therefore, the secret _must_ look like a bunch of random bytes.
 * Avoid "trivial" or structured data such as repeated sequences or a text document.
 * Whenever in doubt about the "randomness" of the blob of bytes,
 * consider employing @ref XXH3_generateSecret() instead (see below).
 * It will generate a proper high entropy secret derived from the blob of bytes.
 * Another advantage of using XXH3_generateSecret() is that
 * it guarantees that all bits within the initial blob of bytes
 * will impact every bit of the output.
 * This is not necessarily the case when using the blob of bytes directly
 * because, when hashing _small_ inputs, only a portion of the secret is employed.
 *
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH3_128bits_withSecret(XXH_NOESCAPE const void* data, size_t len, XXH_NOESCAPE const void* secret, size_t secretSize);

/*******   Streaming   *******/
#ifndef XXH_NO_STREAM
/*
 * Streaming requires state maintenance.
 * This operation costs memory and CPU.
 * As a consequence, streaming is slower than one-shot hashing.
 * For better performance, prefer one-shot functions whenever applicable.
 *
 * XXH3_128bits uses the same XXH3_state_t as XXH3_64bits().
 * Use already declared XXH3_createState() and XXH3_freeState().
 *
 * All reset and streaming functions have same meaning as their 64-bit counterpart.
 */

/*!
 * @brief Resets an @ref XXH3_state_t to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note
 *   - This function resets `statePtr` and generate a secret with default parameters.
 *   - Call it before @ref XXH3_128bits_update().
 *   - Digest will be equivalent to `XXH3_128bits()`.
 */
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset(XXH_NOESCAPE XXH3_state_t* statePtr);

/*!
 * @brief Resets an @ref XXH3_state_t with 64-bit seed to begin a new hash.
 *
 * @param statePtr The state struct to reset.
 * @param seed     The 64-bit seed to alter the hash result predictably.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note
 *   - This function resets `statePtr` and generate a secret from `seed`.
 *   - Call it before @ref XXH3_128bits_update().
 *   - Digest will be equivalent to `XXH3_128bits_withSeed()`.
 */
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSeed(XXH_NOESCAPE XXH3_state_t* statePtr, XXH64_hash_t seed);
/*!
 * @brief Resets an @ref XXH3_state_t with secret data to begin a new hash.
 *
 * @param statePtr   The state struct to reset.
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * `secret` is referenced, it _must outlive_ the hash streaming session.
 * Similar to one-shot API, `secretSize` must be >= @ref XXH3_SECRET_SIZE_MIN,
 * and the quality of produced hash values depends on secret's entropy
 * (secret's content should look like a bunch of random bytes).
 * When in doubt about the randomness of a candidate `secret`,
 * consider employing `XXH3_generateSecret()` instead (see below).
 */
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_reset_withSecret(XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* secret, size_t secretSize);

/*!
 * @brief Consumes a block of @p input to an @ref XXH3_state_t.
 *
 * Call this to incrementally consume blocks of data.
 *
 * @param statePtr The state struct to update.
 * @param input The block of data to be hashed, at least @p length bytes in size.
 * @param length The length of @p input, in bytes.
 *
 * @pre
 *   @p statePtr must not be `NULL`.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @note
 *   The memory between @p input and @p input + @p length must be valid,
 *   readable, contiguous memory. However, if @p length is `0`, @p input may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 */
XXH_PUBLIC_API XXH_errorcode XXH3_128bits_update (XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* input, size_t length);

/*!
 * @brief Returns the calculated XXH3 128-bit hash value from an @ref XXH3_state_t.
 *
 * @param statePtr The state struct to calculate the hash from.
 *
 * @pre
 *  @p statePtr must not be `NULL`.
 *
 * @return The calculated XXH3 128-bit hash value from that state.
 *
 * @note
 *   Calling XXH3_128bits_digest() will not affect @p statePtr, so you can update,
 *   digest, and update again.
 *
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH3_128bits_digest (XXH_NOESCAPE const XXH3_state_t* statePtr);
#endif /* !XXH_NO_STREAM */

/* Following helper functions make it possible to compare XXH128_hast_t values.
 * Since XXH128_hash_t is a structure, this capability is not offered by the language.
 * Note: For better performance, these functions can be inlined using XXH_INLINE_ALL */

/*!
 * @brief Check equality of two XXH128_hash_t values
 *
 * @param h1 The 128-bit hash value.
 * @param h2 Another 128-bit hash value.
 *
 * @return `1` if `h1` and `h2` are equal.
 * @return `0` if they are not.
 */
XXH_PUBLIC_API XXH_PUREF int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2);

/*!
 * @brief Compares two @ref XXH128_hash_t
 *
 * This comparator is compatible with stdlib's `qsort()`/`bsearch()`.
 *
 * @param h128_1 Left-hand side value
 * @param h128_2 Right-hand side value
 *
 * @return >0 if @p h128_1  > @p h128_2
 * @return =0 if @p h128_1 == @p h128_2
 * @return <0 if @p h128_1  < @p h128_2
 */
XXH_PUBLIC_API XXH_PUREF int XXH128_cmp(XXH_NOESCAPE const void* h128_1, XXH_NOESCAPE const void* h128_2);


/*******   Canonical representation   *******/
typedef struct { unsigned char digest[sizeof(XXH128_hash_t)]; } XXH128_canonical_t;


/*!
 * @brief Converts an @ref XXH128_hash_t to a big endian @ref XXH128_canonical_t.
 *
 * @param dst  The @ref XXH128_canonical_t pointer to be stored to.
 * @param hash The @ref XXH128_hash_t to be converted.
 *
 * @pre
 *   @p dst must not be `NULL`.
 * @see @ref canonical_representation_example "Canonical Representation Example"
 */
XXH_PUBLIC_API void XXH128_canonicalFromHash(XXH_NOESCAPE XXH128_canonical_t* dst, XXH128_hash_t hash);

/*!
 * @brief Converts an @ref XXH128_canonical_t to a native @ref XXH128_hash_t.
 *
 * @param src The @ref XXH128_canonical_t to convert.
 *
 * @pre
 *   @p src must not be `NULL`.
 *
 * @return The converted hash.
 * @see @ref canonical_representation_example "Canonical Representation Example"
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH128_hashFromCanonical(XXH_NOESCAPE const XXH128_canonical_t* src);


#endif  /* !XXH_NO_XXH3 */
#endif  /* XXH_NO_LONG_LONG */

/*!
 * @}
 */
#endif /* XXHASH_H_5627135585666179 */



#if defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742)
#define XXHASH_H_STATIC_13879238742
/* ****************************************************************************
 * This section contains declarations which are not guaranteed to remain stable.
 * They may change in future versions, becoming incompatible with a different
 * version of the library.
 * These declarations should only be used with static linking.
 * Never use them in association with dynamic linking!
 ***************************************************************************** */

/*
 * These definitions are only present to allow static allocation
 * of XXH states, on stack or in a struct, for example.
 * Never **ever** access their members directly.
 */

/*!
 * @internal
 * @brief Structure for XXH32 streaming API.
 *
 * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
 * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
 * an opaque type. This allows fields to safely be changed.
 *
 * Typedef'd to @ref XXH32_state_t.
 * Do not access the members of this struct directly.
 * @see XXH64_state_s, XXH3_state_s
 */
struct XXH32_state_s {
   XXH32_hash_t total_len_32; /*!< Total length hashed, modulo 2^32 */
   XXH32_hash_t large_len;    /*!< Whether the hash is >= 16 (handles @ref total_len_32 overflow) */
   XXH32_hash_t v[4];         /*!< Accumulator lanes */
   XXH32_hash_t mem32[4];     /*!< Internal buffer for partial reads. Treated as unsigned char[16]. */
   XXH32_hash_t memsize;      /*!< Amount of data in @ref mem32 */
   XXH32_hash_t reserved;     /*!< Reserved field. Do not read nor write to it. */
};   /* typedef'd to XXH32_state_t */


#ifndef XXH_NO_LONG_LONG  /* defined when there is no 64-bit support */

/*!
 * @internal
 * @brief Structure for XXH64 streaming API.
 *
 * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
 * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined. Otherwise it is
 * an opaque type. This allows fields to safely be changed.
 *
 * Typedef'd to @ref XXH64_state_t.
 * Do not access the members of this struct directly.
 * @see XXH32_state_s, XXH3_state_s
 */
struct XXH64_state_s {
   XXH64_hash_t total_len;    /*!< Total length hashed. This is always 64-bit. */
   XXH64_hash_t v[4];         /*!< Accumulator lanes */
   XXH64_hash_t mem64[4];     /*!< Internal buffer for partial reads. Treated as unsigned char[32]. */
   XXH32_hash_t memsize;      /*!< Amount of data in @ref mem64 */
   XXH32_hash_t reserved32;   /*!< Reserved field, needed for padding anyways*/
   XXH64_hash_t reserved64;   /*!< Reserved field. Do not read or write to it. */
};   /* typedef'd to XXH64_state_t */

#ifndef XXH_NO_XXH3

#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L) /* >= C11 */
#  include <stdalign.h>
#  define XXH_ALIGN(n)      alignas(n)
#elif defined(__cplusplus) && (__cplusplus >= 201103L) /* >= C++11 */
/* In C++ alignas() is a keyword */
#  define XXH_ALIGN(n)      alignas(n)
#elif defined(__GNUC__)
#  define XXH_ALIGN(n)      __attribute__ ((aligned(n)))
#elif defined(_MSC_VER)
#  define XXH_ALIGN(n)      __declspec(align(n))
#else
#  define XXH_ALIGN(n)   /* disabled */
#endif

/* Old GCC versions only accept the attribute after the type in structures. */
#if !(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L))   /* C11+ */ \
    && ! (defined(__cplusplus) && (__cplusplus >= 201103L)) /* >= C++11 */ \
    && defined(__GNUC__)
#   define XXH_ALIGN_MEMBER(align, type) type XXH_ALIGN(align)
#else
#   define XXH_ALIGN_MEMBER(align, type) XXH_ALIGN(align) type
#endif

/*!
 * @brief The size of the internal XXH3 buffer.
 *
 * This is the optimal update size for incremental hashing.
 *
 * @see XXH3_64b_update(), XXH3_128b_update().
 */
#define XXH3_INTERNALBUFFER_SIZE 256

/*!
 * @internal
 * @brief Default size of the secret buffer (and @ref XXH3_kSecret).
 *
 * This is the size used in @ref XXH3_kSecret and the seeded functions.
 *
 * Not to be confused with @ref XXH3_SECRET_SIZE_MIN.
 */
#define XXH3_SECRET_DEFAULT_SIZE 192

/*!
 * @internal
 * @brief Structure for XXH3 streaming API.
 *
 * @note This is only defined when @ref XXH_STATIC_LINKING_ONLY,
 * @ref XXH_INLINE_ALL, or @ref XXH_IMPLEMENTATION is defined.
 * Otherwise it is an opaque type.
 * Never use this definition in combination with dynamic library.
 * This allows fields to safely be changed in the future.
 *
 * @note ** This structure has a strict alignment requirement of 64 bytes!! **
 * Do not allocate this with `malloc()` or `new`,
 * it will not be sufficiently aligned.
 * Use @ref XXH3_createState() and @ref XXH3_freeState(), or stack allocation.
 *
 * Typedef'd to @ref XXH3_state_t.
 * Do never access the members of this struct directly.
 *
 * @see XXH3_INITSTATE() for stack initialization.
 * @see XXH3_createState(), XXH3_freeState().
 * @see XXH32_state_s, XXH64_state_s
 */
struct XXH3_state_s {
   XXH_ALIGN_MEMBER(64, XXH64_hash_t acc[8]);
       /*!< The 8 accumulators. See @ref XXH32_state_s::v and @ref XXH64_state_s::v */
   XXH_ALIGN_MEMBER(64, unsigned char customSecret[XXH3_SECRET_DEFAULT_SIZE]);
       /*!< Used to store a custom secret generated from a seed. */
   XXH_ALIGN_MEMBER(64, unsigned char buffer[XXH3_INTERNALBUFFER_SIZE]);
       /*!< The internal buffer. @see XXH32_state_s::mem32 */
   XXH32_hash_t bufferedSize;
       /*!< The amount of memory in @ref buffer, @see XXH32_state_s::memsize */
   XXH32_hash_t useSeed;
       /*!< Reserved field. Needed for padding on 64-bit. */
   size_t nbStripesSoFar;
       /*!< Number or stripes processed. */
   XXH64_hash_t totalLen;
       /*!< Total length hashed. 64-bit even on 32-bit targets. */
   size_t nbStripesPerBlock;
       /*!< Number of stripes per block. */
   size_t secretLimit;
       /*!< Size of @ref customSecret or @ref extSecret */
   XXH64_hash_t seed;
       /*!< Seed for _withSeed variants. Must be zero otherwise, @see XXH3_INITSTATE() */
   XXH64_hash_t reserved64;
       /*!< Reserved field. */
   const unsigned char* extSecret;
       /*!< Reference to an external secret for the _withSecret variants, NULL
        *   for other variants. */
   /* note: there may be some padding at the end due to alignment on 64 bytes */
}; /* typedef'd to XXH3_state_t */

#undef XXH_ALIGN_MEMBER

/*!
 * @brief Initializes a stack-allocated `XXH3_state_s`.
 *
 * When the @ref XXH3_state_t structure is merely emplaced on stack,
 * it should be initialized with XXH3_INITSTATE() or a memset()
 * in case its first reset uses XXH3_NNbits_reset_withSeed().
 * This init can be omitted if the first reset uses default or _withSecret mode.
 * This operation isn't necessary when the state is created with XXH3_createState().
 * Note that this doesn't prepare the state for a streaming operation,
 * it's still necessary to use XXH3_NNbits_reset*() afterwards.
 */
#define XXH3_INITSTATE(XXH3_state_ptr)                       \
    do {                                                     \
        XXH3_state_t* tmp_xxh3_state_ptr = (XXH3_state_ptr); \
        tmp_xxh3_state_ptr->seed = 0;                        \
        tmp_xxh3_state_ptr->extSecret = NULL;                \
    } while(0)


/*!
 * @brief Calculates the 128-bit hash of @p data using XXH3.
 *
 * @param data The block of data to be hashed, at least @p len bytes in size.
 * @param len  The length of @p data, in bytes.
 * @param seed The 64-bit seed to alter the hash's output predictably.
 *
 * @pre
 *   The memory between @p data and @p data + @p len must be valid,
 *   readable, contiguous memory. However, if @p len is `0`, @p data may be
 *   `NULL`. In C++, this also must be *TriviallyCopyable*.
 *
 * @return The calculated 128-bit XXH3 value.
 *
 * @see @ref single_shot_example "Single Shot Example" for an example.
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t XXH128(XXH_NOESCAPE const void* data, size_t len, XXH64_hash_t seed);


/* ===   Experimental API   === */
/* Symbols defined below must be considered tied to a specific library version. */

/*!
 * @brief Derive a high-entropy secret from any user-defined content, named customSeed.
 *
 * @param secretBuffer    A writable buffer for derived high-entropy secret data.
 * @param secretSize      Size of secretBuffer, in bytes.  Must be >= XXH3_SECRET_DEFAULT_SIZE.
 * @param customSeed      A user-defined content.
 * @param customSeedSize  Size of customSeed, in bytes.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * The generated secret can be used in combination with `*_withSecret()` functions.
 * The `_withSecret()` variants are useful to provide a higher level of protection
 * than 64-bit seed, as it becomes much more difficult for an external actor to
 * guess how to impact the calculation logic.
 *
 * The function accepts as input a custom seed of any length and any content,
 * and derives from it a high-entropy secret of length @p secretSize into an
 * already allocated buffer @p secretBuffer.
 *
 * The generated secret can then be used with any `*_withSecret()` variant.
 * The functions @ref XXH3_128bits_withSecret(), @ref XXH3_64bits_withSecret(),
 * @ref XXH3_128bits_reset_withSecret() and @ref XXH3_64bits_reset_withSecret()
 * are part of this list. They all accept a `secret` parameter
 * which must be large enough for implementation reasons (>= @ref XXH3_SECRET_SIZE_MIN)
 * _and_ feature very high entropy (consist of random-looking bytes).
 * These conditions can be a high bar to meet, so @ref XXH3_generateSecret() can
 * be employed to ensure proper quality.
 *
 * @p customSeed can be anything. It can have any size, even small ones,
 * and its content can be anything, even "poor entropy" sources such as a bunch
 * of zeroes. The resulting `secret` will nonetheless provide all required qualities.
 *
 * @pre
 *   - @p secretSize must be >= @ref XXH3_SECRET_SIZE_MIN
 *   - When @p customSeedSize > 0, supplying NULL as customSeed is undefined behavior.
 *
 * Example code:
 * @code{.c}
 *    #include <stdio.h>
 *    #include <stdlib.h>
 *    #include <string.h>
 *    #define XXH_STATIC_LINKING_ONLY // expose unstable API
 *    #include "xxhash.h"
 *    // Hashes argv[2] using the entropy from argv[1].
 *    int main(int argc, char* argv[])
 *    {
 *        char secret[XXH3_SECRET_SIZE_MIN];
 *        if (argv != 3) { return 1; }
 *        XXH3_generateSecret(secret, sizeof(secret), argv[1], strlen(argv[1]));
 *        XXH64_hash_t h = XXH3_64bits_withSecret(
 *             argv[2], strlen(argv[2]),
 *             secret, sizeof(secret)
 *        );
 *        printf("%016llx\n", (unsigned long long) h);
 *    }
 * @endcode
 */
XXH_PUBLIC_API XXH_errorcode XXH3_generateSecret(XXH_NOESCAPE void* secretBuffer, size_t secretSize, XXH_NOESCAPE const void* customSeed, size_t customSeedSize);

/*!
 * @brief Generate the same secret as the _withSeed() variants.
 *
 * @param secretBuffer A writable buffer of @ref XXH3_SECRET_SIZE_MIN bytes
 * @param seed         The 64-bit seed to alter the hash result predictably.
 *
 * The generated secret can be used in combination with
 *`*_withSecret()` and `_withSecretandSeed()` variants.
 *
 * Example C++ `std::string` hash class:
 * @code{.cpp}
 *    #include <string>
 *    #define XXH_STATIC_LINKING_ONLY // expose unstable API
 *    #include "xxhash.h"
 *    // Slow, seeds each time
 *    class HashSlow {
 *        XXH64_hash_t seed;
 *    public:
 *        HashSlow(XXH64_hash_t s) : seed{s} {}
 *        size_t operator()(const std::string& x) const {
 *            return size_t{XXH3_64bits_withSeed(x.c_str(), x.length(), seed)};
 *        }
 *    };
 *    // Fast, caches the seeded secret for future uses.
 *    class HashFast {
 *        unsigned char secret[XXH3_SECRET_SIZE_MIN];
 *    public:
 *        HashFast(XXH64_hash_t s) {
 *            XXH3_generateSecret_fromSeed(secret, seed);
 *        }
 *        size_t operator()(const std::string& x) const {
 *            return size_t{
 *                XXH3_64bits_withSecret(x.c_str(), x.length(), secret, sizeof(secret))
 *            };
 *        }
 *    };
 * @endcode
 */
XXH_PUBLIC_API void XXH3_generateSecret_fromSeed(XXH_NOESCAPE void* secretBuffer, XXH64_hash_t seed);

/*!
 * @brief Calculates 64/128-bit seeded variant of XXH3 hash of @p data.
 *
 * @param data       The block of data to be hashed, at least @p len bytes in size.
 * @param len        The length of @p data, in bytes.
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 * @param seed       The 64-bit seed to alter the hash result predictably.
 *
 * These variants generate hash values using either
 * @p seed for "short" keys (< @ref XXH3_MIDSIZE_MAX = 240 bytes)
 * or @p secret for "large" keys (>= @ref XXH3_MIDSIZE_MAX).
 *
 * This generally benefits speed, compared to `_withSeed()` or `_withSecret()`.
 * `_withSeed()` has to generate the secret on the fly for "large" keys.
 * It's fast, but can be perceptible for "not so large" keys (< 1 KB).
 * `_withSecret()` has to generate the masks on the fly for "small" keys,
 * which requires more instructions than _withSeed() variants.
 * Therefore, _withSecretandSeed variant combines the best of both worlds.
 *
 * When @p secret has been generated by XXH3_generateSecret_fromSeed(),
 * this variant produces *exactly* the same results as `_withSeed()` variant,
 * hence offering only a pure speed benefit on "large" input,
 * by skipping the need to regenerate the secret for every large input.
 *
 * Another usage scenario is to hash the secret to a 64-bit hash value,
 * for example with XXH3_64bits(), which then becomes the seed,
 * and then employ both the seed and the secret in _withSecretandSeed().
 * On top of speed, an added benefit is that each bit in the secret
 * has a 50% chance to swap each bit in the output, via its impact to the seed.
 *
 * This is not guaranteed when using the secret directly in "small data" scenarios,
 * because only portions of the secret are employed for small data.
 */
XXH_PUBLIC_API XXH_PUREF XXH64_hash_t
XXH3_64bits_withSecretandSeed(XXH_NOESCAPE const void* data, size_t len,
                              XXH_NOESCAPE const void* secret, size_t secretSize,
                              XXH64_hash_t seed);
/*!
 * @brief Calculates 128-bit seeded variant of XXH3 hash of @p data.
 *
 * @param input      The block of data to be hashed, at least @p len bytes in size.
 * @param length     The length of @p data, in bytes.
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 * @param seed64     The 64-bit seed to alter the hash result predictably.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @see XXH3_64bits_withSecretandSeed()
 */
XXH_PUBLIC_API XXH_PUREF XXH128_hash_t
XXH3_128bits_withSecretandSeed(XXH_NOESCAPE const void* input, size_t length,
                               XXH_NOESCAPE const void* secret, size_t secretSize,
                               XXH64_hash_t seed64);
#ifndef XXH_NO_STREAM
/*!
 * @brief Resets an @ref XXH3_state_t with secret data to begin a new hash.
 *
 * @param statePtr   A pointer to an @ref XXH3_state_t allocated with @ref XXH3_createState().
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 * @param seed64     The 64-bit seed to alter the hash result predictably.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @see XXH3_64bits_withSecretandSeed()
 */
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset_withSecretandSeed(XXH_NOESCAPE XXH3_state_t* statePtr,
                                    XXH_NOESCAPE const void* secret, size_t secretSize,
                                    XXH64_hash_t seed64);
/*!
 * @brief Resets an @ref XXH3_state_t with secret data to begin a new hash.
 *
 * @param statePtr   A pointer to an @ref XXH3_state_t allocated with @ref XXH3_createState().
 * @param secret     The secret data.
 * @param secretSize The length of @p secret, in bytes.
 * @param seed64     The 64-bit seed to alter the hash result predictably.
 *
 * @return @ref XXH_OK on success.
 * @return @ref XXH_ERROR on failure.
 *
 * @see XXH3_64bits_withSecretandSeed()
 */
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset_withSecretandSeed(XXH_NOESCAPE XXH3_state_t* statePtr,
                                     XXH_NOESCAPE const void* secret, size_t secretSize,
                                     XXH64_hash_t seed64);
#endif /* !XXH_NO_STREAM */

#endif  /* !XXH_NO_XXH3 */
#endif  /* XXH_NO_LONG_LONG */
#if defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API)
#  define XXH_IMPLEMENTATION
#endif

#endif  /* defined(XXH_STATIC_LINKING_ONLY) && !defined(XXHASH_H_STATIC_13879238742) */


/* ======================================================================== */
/* ======================================================================== */
/* ======================================================================== */


/*-**********************************************************************
 * xxHash implementation
 *-**********************************************************************
 * xxHash's implementation used to be hosted inside xxhash.c.
 *
 * However, inlining requires implementation to be visible to the compiler,
 * hence be included alongside the header.
 * Previously, implementation was hosted inside xxhash.c,
 * which was then #included when inlining was activated.
 * This construction created issues with a few build and install systems,
 * as it required xxhash.c to be stored in /include directory.
 *
 * xxHash implementation is now directly integrated within xxhash.h.
 * As a consequence, xxhash.c is no longer needed in /include.
 *
 * xxhash.c is still available and is still useful.
 * In a "normal" setup, when xxhash is not inlined,
 * xxhash.h only exposes the prototypes and public symbols,
 * while xxhash.c can be built into an object file xxhash.o
 * which can then be linked into the final binary.
 ************************************************************************/

#if ( defined(XXH_INLINE_ALL) || defined(XXH_PRIVATE_API) \
   || defined(XXH_IMPLEMENTATION) ) && !defined(XXH_IMPLEM_13a8737387)
#  define XXH_IMPLEM_13a8737387

/* *************************************
*  Tuning parameters
***************************************/

/*!
 * @defgroup tuning Tuning parameters
 * @{
 *
 * Various macros to control xxHash's behavior.
 */
#ifdef XXH_DOXYGEN
/*!
 * @brief Define this to disable 64-bit code.
 *
 * Useful if only using the @ref XXH32_family and you have a strict C90 compiler.
 */
#  define XXH_NO_LONG_LONG
#  undef XXH_NO_LONG_LONG /* don't actually */
/*!
 * @brief Controls how unaligned memory is accessed.
 *
 * By default, access to unaligned memory is controlled by `memcpy()`, which is
 * safe and portable.
 *
 * Unfortunately, on some target/compiler combinations, the generated assembly
 * is sub-optimal.
 *
 * The below switch allow selection of a different access method
 * in the search for improved performance.
 *
 * @par Possible options:
 *
 *  - `XXH_FORCE_MEMORY_ACCESS=0` (default): `memcpy`
 *   @par
 *     Use `memcpy()`. Safe and portable. Note that most modern compilers will
 *     eliminate the function call and treat it as an unaligned access.
 *
 *  - `XXH_FORCE_MEMORY_ACCESS=1`: `__attribute__((aligned(1)))`
 *   @par
 *     Depends on compiler extensions and is therefore not portable.
 *     This method is safe _if_ your compiler supports it,
 *     and *generally* as fast or faster than `memcpy`.
 *
 *  - `XXH_FORCE_MEMORY_ACCESS=2`: Direct cast
 *  @par
 *     Casts directly and dereferences. This method doesn't depend on the
 *     compiler, but it violates the C standard as it directly dereferences an
 *     unaligned pointer. It can generate buggy code on targets which do not
 *     support unaligned memory accesses, but in some circumstances, it's the
 *     only known way to get the most performance.
 *
 *  - `XXH_FORCE_MEMORY_ACCESS=3`: Byteshift
 *  @par
 *     Also portable. This can generate the best code on old compilers which don't
 *     inline small `memcpy()` calls, and it might also be faster on big-endian
 *     systems which lack a native byteswap instruction. However, some compilers
 *     will emit literal byteshifts even if the target supports unaligned access.
 *
 *
 * @warning
 *   Methods 1 and 2 rely on implementation-defined behavior. Use these with
 *   care, as what works on one compiler/platform/optimization level may cause
 *   another to read garbage data or even crash.
 *
 * See https://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html for details.
 *
 * Prefer these methods in priority order (0 > 3 > 1 > 2)
 */
#  define XXH_FORCE_MEMORY_ACCESS 0

/*!
 * @def XXH_SIZE_OPT
 * @brief Controls how much xxHash optimizes for size.
 *
 * xxHash, when compiled, tends to result in a rather large binary size. This
 * is mostly due to heavy usage to forced inlining and constant folding of the
 * @ref XXH3_family to increase performance.
 *
 * However, some developers prefer size over speed. This option can
 * significantly reduce the size of the generated code. When using the `-Os`
 * or `-Oz` options on GCC or Clang, this is defined to 1 by default,
 * otherwise it is defined to 0.
 *
 * Most of these size optimizations can be controlled manually.
 *
 * This is a number from 0-2.
 *  - `XXH_SIZE_OPT` == 0: Default. xxHash makes no size optimizations. Speed
 *    comes first.
 *  - `XXH_SIZE_OPT` == 1: Default for `-Os` and `-Oz`. xxHash is more
 *    conservative and disables hacks that increase code size. It implies the
 *    options @ref XXH_NO_INLINE_HINTS == 1, @ref XXH_FORCE_ALIGN_CHECK == 0,
 *    and @ref XXH3_NEON_LANES == 8 if they are not already defined.
 *  - `XXH_SIZE_OPT` == 2: xxHash tries to make itself as small as possible.
 *    Performance may cry. For example, the single shot functions just use the
 *    streaming API.
 */
#  define XXH_SIZE_OPT 0

/*!
 * @def XXH_FORCE_ALIGN_CHECK
 * @brief If defined to non-zero, adds a special path for aligned inputs (XXH32()
 * and XXH64() only).
 *
 * This is an important performance trick for architectures without decent
 * unaligned memory access performance.
 *
 * It checks for input alignment, and when conditions are met, uses a "fast
 * path" employing direct 32-bit/64-bit reads, resulting in _dramatically
 * faster_ read speed.
 *
 * The check costs one initial branch per hash, which is generally negligible,
 * but not zero.
 *
 * Moreover, it's not useful to generate an additional code path if memory
 * access uses the same instruction for both aligned and unaligned
 * addresses (e.g. x86 and aarch64).
 *
 * In these cases, the alignment check can be removed by setting this macro to 0.
 * Then the code will always use unaligned memory access.
 * Align check is automatically disabled on x86, x64, ARM64, and some ARM chips
 * which are platforms known to offer good unaligned memory accesses performance.
 *
 * It is also disabled by default when @ref XXH_SIZE_OPT >= 1.
 *
 * This option does not affect XXH3 (only XXH32 and XXH64).
 */
#  define XXH_FORCE_ALIGN_CHECK 0

/*!
 * @def XXH_NO_INLINE_HINTS
 * @brief When non-zero, sets all functions to `static`.
 *
 * By default, xxHash tries to force the compiler to inline almost all internal
 * functions.
 *
 * This can usually improve performance due to reduced jumping and improved
 * constant folding, but significantly increases the size of the binary which
 * might not be favorable.
 *
 * Additionally, sometimes the forced inlining can be detrimental to performance,
 * depending on the architecture.
 *
 * XXH_NO_INLINE_HINTS marks all internal functions as static, giving the
 * compiler full control on whether to inline or not.
 *
 * When not optimizing (-O0), using `-fno-inline` with GCC or Clang, or if
 * @ref XXH_SIZE_OPT >= 1, this will automatically be defined.
 */
#  define XXH_NO_INLINE_HINTS 0

/*!
 * @def XXH3_INLINE_SECRET
 * @brief Determines whether to inline the XXH3 withSecret code.
 *
 * When the secret size is known, the compiler can improve the performance
 * of XXH3_64bits_withSecret() and XXH3_128bits_withSecret().
 *
 * However, if the secret size is not known, it doesn't have any benefit. This
 * happens when xxHash is compiled into a global symbol. Therefore, if
 * @ref XXH_INLINE_ALL is *not* defined, this will be defined to 0.
 *
 * Additionally, this defaults to 0 on GCC 12+, which has an issue with function pointers
 * that are *sometimes* force inline on -Og, and it is impossible to automatically
 * detect this optimization level.
 */
#  define XXH3_INLINE_SECRET 0

/*!
 * @def XXH32_ENDJMP
 * @brief Whether to use a jump for `XXH32_finalize`.
 *
 * For performance, `XXH32_finalize` uses multiple branches in the finalizer.
 * This is generally preferable for performance,
 * but depending on exact architecture, a jmp may be preferable.
 *
 * This setting is only possibly making a difference for very small inputs.
 */
#  define XXH32_ENDJMP 0

/*!
 * @internal
 * @brief Redefines old internal names.
 *
 * For compatibility with code that uses xxHash's internals before the names
 * were changed to improve namespacing. There is no other reason to use this.
 */
#  define XXH_OLD_NAMES
#  undef XXH_OLD_NAMES /* don't actually use, it is ugly. */

/*!
 * @def XXH_NO_STREAM
 * @brief Disables the streaming API.
 *
 * When xxHash is not inlined and the streaming functions are not used, disabling
 * the streaming functions can improve code size significantly, especially with
 * the @ref XXH3_family which tends to make constant folded copies of itself.
 */
#  define XXH_NO_STREAM
#  undef XXH_NO_STREAM /* don't actually */
#endif /* XXH_DOXYGEN */
/*!
 * @}
 */

#ifndef XXH_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
   /* prefer __packed__ structures (method 1) for GCC
    * < ARMv7 with unaligned access (e.g. Raspbian armhf) still uses byte shifting, so we use memcpy
    * which for some reason does unaligned loads. */
#  if defined(__GNUC__) && !(defined(__ARM_ARCH) && __ARM_ARCH < 7 && defined(__ARM_FEATURE_UNALIGNED))
#    define XXH_FORCE_MEMORY_ACCESS 1
#  endif
#endif

#ifndef XXH_SIZE_OPT
   /* default to 1 for -Os or -Oz */
#  if (defined(__GNUC__) || defined(__clang__)) && defined(__OPTIMIZE_SIZE__)
#    define XXH_SIZE_OPT 1
#  else
#    define XXH_SIZE_OPT 0
#  endif
#endif

#ifndef XXH_FORCE_ALIGN_CHECK  /* can be defined externally */
   /* don't check on sizeopt, x86, aarch64, or arm when unaligned access is available */
#  if XXH_SIZE_OPT >= 1 || \
      defined(__i386)  || defined(__x86_64__) || defined(__aarch64__) || defined(__ARM_FEATURE_UNALIGNED) \
   || defined(_M_IX86) || defined(_M_X64)     || defined(_M_ARM64)    || defined(_M_ARM) /* visual */
#    define XXH_FORCE_ALIGN_CHECK 0
#  else
#    define XXH_FORCE_ALIGN_CHECK 1
#  endif
#endif

#ifndef XXH_NO_INLINE_HINTS
#  if XXH_SIZE_OPT >= 1 || defined(__NO_INLINE__)  /* -O0, -fno-inline */
#    define XXH_NO_INLINE_HINTS 1
#  else
#    define XXH_NO_INLINE_HINTS 0
#  endif
#endif

#ifndef XXH3_INLINE_SECRET
#  if (defined(__GNUC__) && !defined(__clang__) && __GNUC__ >= 12) \
     || !defined(XXH_INLINE_ALL)
#    define XXH3_INLINE_SECRET 0
#  else
#    define XXH3_INLINE_SECRET 1
#  endif
#endif

#ifndef XXH32_ENDJMP
/* generally preferable for performance */
#  define XXH32_ENDJMP 0
#endif

/*!
 * @defgroup impl Implementation
 * @{
 */


/* *************************************
*  Includes & Memory related functions
***************************************/
#if defined(XXH_NO_STREAM)
/* nothing */
#elif defined(XXH_NO_STDLIB)

/* When requesting to disable any mention of stdlib,
 * the library loses the ability to invoked malloc / free.
 * In practice, it means that functions like `XXH*_createState()`
 * will always fail, and return NULL.
 * This flag is useful in situations where
 * xxhash.h is integrated into some kernel, embedded or limited environment
 * without access to dynamic allocation.
 */

static void XXH_free(void* p) { (void)p; }

#else

/*
 * Modify the local functions below should you wish to use
 * different memory routines for malloc() and free()
 */
#include <stdlib.h>


/*!
 * @internal
 * @brief Modify this function to use a different routine than free().
 */
static void XXH_free(void* p) { VG_(free)(p); }

#endif  /* XXH_NO_STDLIB */

#include <string.h>

/*!
 * @internal
 * @brief Modify this function to use a different routine than memcpy().
 */
static void* XXH_memcpy(void* dest, const void* src, size_t size)
{
    return VG_(memcpy)(dest,src,size);
}

#include <limits.h>   /* ULLONG_MAX */


/* *************************************
*  Compiler Specific Options
***************************************/
#ifdef _MSC_VER /* Visual Studio warning fix */
#  pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
#endif

#if XXH_NO_INLINE_HINTS  /* disable inlining hints */
#  if defined(__GNUC__) || defined(__clang__)
#    define XXH_FORCE_INLINE static __attribute__((unused))
#  else
#    define XXH_FORCE_INLINE static
#  endif
#  define XXH_NO_INLINE static
/* enable inlining hints */
#elif defined(__GNUC__) || defined(__clang__)
#  define XXH_FORCE_INLINE static __inline__ __attribute__((always_inline, unused))
#  define XXH_NO_INLINE static __attribute__((noinline))
#elif defined(_MSC_VER)  /* Visual Studio */
#  define XXH_FORCE_INLINE static __forceinline
#  define XXH_NO_INLINE static __declspec(noinline)
#elif defined (__cplusplus) \
  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L))   /* C99 */
#  define XXH_FORCE_INLINE static inline
#  define XXH_NO_INLINE static
#else
#  define XXH_FORCE_INLINE static
#  define XXH_NO_INLINE static
#endif

#if XXH3_INLINE_SECRET
#  define XXH3_WITH_SECRET_INLINE XXH_FORCE_INLINE
#else
#  define XXH3_WITH_SECRET_INLINE XXH_NO_INLINE
#endif


/* *************************************
*  Debug
***************************************/
/*!
 * @ingroup tuning
 * @def XXH_DEBUGLEVEL
 * @brief Sets the debugging level.
 *
 * XXH_DEBUGLEVEL is expected to be defined externally, typically via the
 * compiler's command line options. The value must be a number.
 */
#ifndef XXH_DEBUGLEVEL
#  ifdef DEBUGLEVEL /* backwards compat */
#    define XXH_DEBUGLEVEL DEBUGLEVEL
#  else
#    define XXH_DEBUGLEVEL 0
#  endif
#endif

#if (XXH_DEBUGLEVEL>=1)
#  include <assert.h>   /* note: can still be disabled with NDEBUG */
#  define XXH_ASSERT(c)   assert(c)
#else
#  if defined(__INTEL_COMPILER)
#    define XXH_ASSERT(c)   XXH_ASSUME((unsigned char) (c))
#  else
#    define XXH_ASSERT(c)   XXH_ASSUME(c)
#  endif
#endif

/* note: use after variable declarations */
#ifndef XXH_STATIC_ASSERT
#  if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)    /* C11 */
#    define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { _Static_assert((c),m); } while(0)
#  elif defined(__cplusplus) && (__cplusplus >= 201103L)            /* C++11 */
#    define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { static_assert((c),m); } while(0)
#  else
#    define XXH_STATIC_ASSERT_WITH_MESSAGE(c,m) do { struct xxh_sa { char x[(c) ? 1 : -1]; }; } while(0)
#  endif
#  define XXH_STATIC_ASSERT(c) XXH_STATIC_ASSERT_WITH_MESSAGE((c),#c)
#endif

/*!
 * @internal
 * @def XXH_COMPILER_GUARD(var)
 * @brief Used to prevent unwanted optimizations for @p var.
 *
 * It uses an empty GCC inline assembly statement with a register constraint
 * which forces @p var into a general purpose register (eg eax, ebx, ecx
 * on x86) and marks it as modified.
 *
 * This is used in a few places to avoid unwanted autovectorization (e.g.
 * XXH32_round()). All vectorization we want is explicit via intrinsics,
 * and _usually_ isn't wanted elsewhere.
 *
 * We also use it to prevent unwanted constant folding for AArch64 in
 * XXH3_initCustomSecret_scalar().
 */
#if defined(__GNUC__) || defined(__clang__)
#  define XXH_COMPILER_GUARD(var) __asm__("" : "+r" (var))
#else
#  define XXH_COMPILER_GUARD(var) ((void)0)
#endif

/* Specifically for NEON vectors which use the "w" constraint, on
 * Clang. */
#if defined(__clang__) && defined(__ARM_ARCH) && !defined(__wasm__)
#  define XXH_COMPILER_GUARD_CLANG_NEON(var) __asm__("" : "+w" (var))
#else
#  define XXH_COMPILER_GUARD_CLANG_NEON(var) ((void)0)
#endif

/* *************************************
*  Basic Types
***************************************/
#if !defined (__VMS) \
 && (defined (__cplusplus) \
 || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
# ifdef _AIX
#   include <inttypes.h>
# else
#   include <stdint.h>
# endif
  typedef uint8_t xxh_u8;
#else
  typedef unsigned char xxh_u8;
#endif
typedef XXH32_hash_t xxh_u32;

#ifdef XXH_OLD_NAMES
#  warning "XXH_OLD_NAMES is planned to be removed starting v0.9. If the program depends on it, consider moving away from it by employing newer type names directly"
#  define BYTE xxh_u8
#  define U8   xxh_u8
#  define U32  xxh_u32
#endif

/* ***   Memory access   *** */

/*!
 * @internal
 * @fn xxh_u32 XXH_read32(const void* ptr)
 * @brief Reads an unaligned 32-bit integer from @p ptr in native endianness.
 *
 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
 *
 * @param ptr The pointer to read from.
 * @return The 32-bit native endian integer from the bytes at @p ptr.
 */

/*!
 * @internal
 * @fn xxh_u32 XXH_readLE32(const void* ptr)
 * @brief Reads an unaligned 32-bit little endian integer from @p ptr.
 *
 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
 *
 * @param ptr The pointer to read from.
 * @return The 32-bit little endian integer from the bytes at @p ptr.
 */

/*!
 * @internal
 * @fn xxh_u32 XXH_readBE32(const void* ptr)
 * @brief Reads an unaligned 32-bit big endian integer from @p ptr.
 *
 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
 *
 * @param ptr The pointer to read from.
 * @return The 32-bit big endian integer from the bytes at @p ptr.
 */

/*!
 * @internal
 * @fn xxh_u32 XXH_readLE32_align(const void* ptr, XXH_alignment align)
 * @brief Like @ref XXH_readLE32(), but has an option for aligned reads.
 *
 * Affected by @ref XXH_FORCE_MEMORY_ACCESS.
 * Note that when @ref XXH_FORCE_ALIGN_CHECK == 0, the @p align parameter is
 * always @ref XXH_alignment::XXH_unaligned.
 *
 * @param ptr The pointer to read from.
 * @param align Whether @p ptr is aligned.
 * @pre
 *   If @p align == @ref XXH_alignment::XXH_aligned, @p ptr must be 4 byte
 *   aligned.
 * @return The 32-bit little endian integer from the bytes at @p ptr.
 */

#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
/*
 * Manual byteshift. Best for old compilers which don't inline memcpy.
 * We actually directly use XXH_readLE32 and XXH_readBE32.
 */
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))

/*
 * Force direct memory access. Only works on CPU which support unaligned memory
 * access in hardware.
 */
static xxh_u32 XXH_read32(const void* memPtr) { return *(const xxh_u32*) memPtr; }

#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))

/*
 * __attribute__((aligned(1))) is supported by gcc and clang. Originally the
 * documentation claimed that it only increased the alignment, but actually it
 * can decrease it on gcc, clang, and icc:
 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69502,
 * https://gcc.godbolt.org/z/xYez1j67Y.
 */
#ifdef XXH_OLD_NAMES
typedef union { xxh_u32 u32; } __attribute__((packed)) unalign;
#endif
static xxh_u32 XXH_read32(const void* ptr)
{
    typedef __attribute__((aligned(1))) xxh_u32 xxh_unalign32;
    return *((const xxh_unalign32*)ptr);
}

#else

/*
 * Portable and safe solution. Generally efficient.
 * see: https://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html
 */
static xxh_u32 XXH_read32(const void* memPtr)
{
    xxh_u32 val;
    XXH_memcpy(&val, memPtr, sizeof(val));
    return val;
}

#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */


/* ***   Endianness   *** */

/*!
 * @ingroup tuning
 * @def XXH_CPU_LITTLE_ENDIAN
 * @brief Whether the target is little endian.
 *
 * Defined to 1 if the target is little endian, or 0 if it is big endian.
 * It can be defined externally, for example on the compiler command line.
 *
 * If it is not defined,
 * a runtime check (which is usually constant folded) is used instead.
 *
 * @note
 *   This is not necessarily defined to an integer constant.
 *
 * @see XXH_isLittleEndian() for the runtime check.
 */
#ifndef XXH_CPU_LITTLE_ENDIAN
/*
 * Try to detect endianness automatically, to avoid the nonstandard behavior
 * in `XXH_isLittleEndian()`
 */
#  if defined(_WIN32) /* Windows is always little endian */ \
     || defined(__LITTLE_ENDIAN__) \
     || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
#    define XXH_CPU_LITTLE_ENDIAN 1
#  elif defined(__BIG_ENDIAN__) \
     || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
#    define XXH_CPU_LITTLE_ENDIAN 0
#  else
/*!
 * @internal
 * @brief Runtime check for @ref XXH_CPU_LITTLE_ENDIAN.
 *
 * Most compilers will constant fold this.
 */
static int XXH_isLittleEndian(void)
{
    /*
     * Portable and well-defined behavior.
     * Don't use static: it is detrimental to performance.
     */
    const union { xxh_u32 u; xxh_u8 c[4]; } one = { 1 };
    return one.c[0];
}
#   define XXH_CPU_LITTLE_ENDIAN   XXH_isLittleEndian()
#  endif
#endif




/* ****************************************
*  Compiler-specific Functions and Macros
******************************************/
#define XXH_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)

#ifdef __has_builtin
#  define XXH_HAS_BUILTIN(x) __has_builtin(x)
#else
#  define XXH_HAS_BUILTIN(x) 0
#endif



/*
 * C23 and future versions have standard "unreachable()".
 * Once it has been implemented reliably we can add it as an
 * additional case:
 *
 * ```
 * #if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= XXH_C23_VN)
 * #  include <stddef.h>
 * #  ifdef unreachable
 * #    define XXH_UNREACHABLE() unreachable()
 * #  endif
 * #endif
 * ```
 *
 * Note C++23 also has std::unreachable() which can be detected
 * as follows:
 * ```
 * #if defined(__cpp_lib_unreachable) && (__cpp_lib_unreachable >= 202202L)
 * #  include <utility>
 * #  define XXH_UNREACHABLE() std::unreachable()
 * #endif
 * ```
 * NB: `__cpp_lib_unreachable` is defined in the `<version>` header.
 * We don't use that as including `<utility>` in `extern "C"` blocks
 * doesn't work on GCC12
 */

#if XXH_HAS_BUILTIN(__builtin_unreachable)
#  define XXH_UNREACHABLE() __builtin_unreachable()

#elif defined(_MSC_VER)
#  define XXH_UNREACHABLE() __assume(0)

#else
#  define XXH_UNREACHABLE()
#endif

#if XXH_HAS_BUILTIN(__builtin_assume)
#  define XXH_ASSUME(c) __builtin_assume(c)
#else
#  define XXH_ASSUME(c) if (!(c)) { XXH_UNREACHABLE(); }
#endif

/*!
 * @internal
 * @def XXH_rotl32(x,r)
 * @brief 32-bit rotate left.
 *
 * @param x The 32-bit integer to be rotated.
 * @param r The number of bits to rotate.
 * @pre
 *   @p r > 0 && @p r < 32
 * @note
 *   @p x and @p r may be evaluated multiple times.
 * @return The rotated result.
 */
#if !defined(NO_CLANG_BUILTIN) && XXH_HAS_BUILTIN(__builtin_rotateleft32) \
                               && XXH_HAS_BUILTIN(__builtin_rotateleft64)
#  define XXH_rotl32 __builtin_rotateleft32
#  define XXH_rotl64 __builtin_rotateleft64
/* Note: although _rotl exists for minGW (GCC under windows), performance seems poor */
#elif defined(_MSC_VER)
#  define XXH_rotl32(x,r) _rotl(x,r)
#  define XXH_rotl64(x,r) _rotl64(x,r)
#else
#  define XXH_rotl32(x,r) (((x) << (r)) | ((x) >> (32 - (r))))
#  define XXH_rotl64(x,r) (((x) << (r)) | ((x) >> (64 - (r))))
#endif

/*!
 * @internal
 * @fn xxh_u32 XXH_swap32(xxh_u32 x)
 * @brief A 32-bit byteswap.
 *
 * @param x The 32-bit integer to byteswap.
 * @return @p x, byteswapped.
 */
#if defined(_MSC_VER)     /* Visual Studio */
#  define XXH_swap32 _byteswap_ulong
#elif XXH_GCC_VERSION >= 403
#  define XXH_swap32 __builtin_bswap32
#else
static xxh_u32 XXH_swap32 (xxh_u32 x)
{
    return  ((x << 24) & 0xff000000 ) |
            ((x <<  8) & 0x00ff0000 ) |
            ((x >>  8) & 0x0000ff00 ) |
            ((x >> 24) & 0x000000ff );
}
#endif


/* ***************************
*  Memory reads
*****************************/

/*!
 * @internal
 * @brief Enum to indicate whether a pointer is aligned.
 */
typedef enum {
    XXH_aligned,  /*!< Aligned */
    XXH_unaligned /*!< Possibly unaligned */
} XXH_alignment;

/*
 * XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load.
 *
 * This is ideal for older compilers which don't inline memcpy.
 */
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))

XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* memPtr)
{
    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
    return bytePtr[0]
         | ((xxh_u32)bytePtr[1] << 8)
         | ((xxh_u32)bytePtr[2] << 16)
         | ((xxh_u32)bytePtr[3] << 24);
}

XXH_FORCE_INLINE xxh_u32 XXH_readBE32(const void* memPtr)
{
    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
    return bytePtr[3]
         | ((xxh_u32)bytePtr[2] << 8)
         | ((xxh_u32)bytePtr[1] << 16)
         | ((xxh_u32)bytePtr[0] << 24);
}

#else
XXH_FORCE_INLINE xxh_u32 XXH_readLE32(const void* ptr)
{
    return XXH_CPU_LITTLE_ENDIAN ? XXH_read32(ptr) : XXH_swap32(XXH_read32(ptr));
}

static xxh_u32 XXH_readBE32(const void* ptr)
{
    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap32(XXH_read32(ptr)) : XXH_read32(ptr);
}
#endif

XXH_FORCE_INLINE xxh_u32
XXH_readLE32_align(const void* ptr, XXH_alignment align)
{
    if (align==XXH_unaligned) {
        return XXH_readLE32(ptr);
    } else {
        return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u32*)ptr : XXH_swap32(*(const xxh_u32*)ptr);
    }
}


/* *************************************
*  Misc
***************************************/
/*! @ingroup public */
XXH_PUBLIC_API unsigned XXH_versionNumber (void) { return XXH_VERSION_NUMBER; }


/* *******************************************************************
*  32-bit hash functions
*********************************************************************/
/*!
 * @}
 * @defgroup XXH32_impl XXH32 implementation
 * @ingroup impl
 *
 * Details on the XXH32 implementation.
 * @{
 */
 /* #define instead of static const, to be used as initializers */
#define XXH_PRIME32_1  0x9E3779B1U  /*!< 0b10011110001101110111100110110001 */
#define XXH_PRIME32_2  0x85EBCA77U  /*!< 0b10000101111010111100101001110111 */
#define XXH_PRIME32_3  0xC2B2AE3DU  /*!< 0b11000010101100101010111000111101 */
#define XXH_PRIME32_4  0x27D4EB2FU  /*!< 0b00100111110101001110101100101111 */
#define XXH_PRIME32_5  0x165667B1U  /*!< 0b00010110010101100110011110110001 */

#ifdef XXH_OLD_NAMES
#  define PRIME32_1 XXH_PRIME32_1
#  define PRIME32_2 XXH_PRIME32_2
#  define PRIME32_3 XXH_PRIME32_3
#  define PRIME32_4 XXH_PRIME32_4
#  define PRIME32_5 XXH_PRIME32_5
#endif

/*!
 * @internal
 * @brief Normal stripe processing routine.
 *
 * This shuffles the bits so that any bit from @p input impacts several bits in
 * @p acc.
 *
 * @param acc The accumulator lane.
 * @param input The stripe of input to mix.
 * @return The mixed accumulator lane.
 */
static xxh_u32 XXH32_round(xxh_u32 acc, xxh_u32 input)
{
    acc += input * XXH_PRIME32_2;
    acc  = XXH_rotl32(acc, 13);
    acc *= XXH_PRIME32_1;
#if (defined(__SSE4_1__) || defined(__aarch64__) || defined(__wasm_simd128__)) && !defined(XXH_ENABLE_AUTOVECTORIZE)
    /*
     * UGLY HACK:
     * A compiler fence is the only thing that prevents GCC and Clang from
     * autovectorizing the XXH32 loop (pragmas and attributes don't work for some
     * reason) without globally disabling SSE4.1.
     *
     * The reason we want to avoid vectorization is because despite working on
     * 4 integers at a time, there are multiple factors slowing XXH32 down on
     * SSE4:
     * - There's a ridiculous amount of lag from pmulld (10 cycles of latency on
     *   newer chips!) making it slightly slower to multiply four integers at
     *   once compared to four integers independently. Even when pmulld was
     *   fastest, Sandy/Ivy Bridge, it is still not worth it to go into SSE
     *   just to multiply unless doing a long operation.
     *
     * - Four instructions are required to rotate,
     *      movqda tmp,  v // not required with VEX encoding
     *      pslld  tmp, 13 // tmp <<= 13
     *      psrld  v,   19 // x >>= 19
     *      por    v,  tmp // x |= tmp
     *   compared to one for scalar:
     *      roll   v, 13    // reliably fast across the board
     *      shldl  v, v, 13 // Sandy Bridge and later prefer this for some reason
     *
     * - Instruction level parallelism is actually more beneficial here because
     *   the SIMD actually serializes this operation: While v1 is rotating, v2
     *   can load data, while v3 can multiply. SSE forces them to operate
     *   together.
     *
     * This is also enabled on AArch64, as Clang is *very aggressive* in vectorizing
     * the loop. NEON is only faster on the A53, and with the newer cores, it is less
     * than half the speed.
     *
     * Additionally, this is used on WASM SIMD128 because it JITs to the same
     * SIMD instructions and has the same issue.
     */
    XXH_COMPILER_GUARD(acc);
#endif
    return acc;
}

/*!
 * @internal
 * @brief Mixes all bits to finalize the hash.
 *
 * The final mix ensures that all input bits have a chance to impact any bit in
 * the output digest, resulting in an unbiased distribution.
 *
 * @param hash The hash to avalanche.
 * @return The avalanched hash.
 */
static xxh_u32 XXH32_avalanche(xxh_u32 hash)
{
    hash ^= hash >> 15;
    hash *= XXH_PRIME32_2;
    hash ^= hash >> 13;
    hash *= XXH_PRIME32_3;
    hash ^= hash >> 16;
    return hash;
}

#define XXH_get32bits(p) XXH_readLE32_align(p, align)

/*!
 * @internal
 * @brief Processes the last 0-15 bytes of @p ptr.
 *
 * There may be up to 15 bytes remaining to consume from the input.
 * This final stage will digest them to ensure that all input bytes are present
 * in the final mix.
 *
 * @param hash The hash to finalize.
 * @param ptr The pointer to the remaining input.
 * @param len The remaining length, modulo 16.
 * @param align Whether @p ptr is aligned.
 * @return The finalized hash.
 * @see XXH64_finalize().
 */
static XXH_PUREF xxh_u32
XXH32_finalize(xxh_u32 hash, const xxh_u8* ptr, size_t len, XXH_alignment align)
{
#define XXH_PROCESS1 do {                             \
    hash += (*ptr++) * XXH_PRIME32_5;                 \
    hash = XXH_rotl32(hash, 11) * XXH_PRIME32_1;      \
} while (0)

#define XXH_PROCESS4 do {                             \
    hash += XXH_get32bits(ptr) * XXH_PRIME32_3;       \
    ptr += 4;                                         \
    hash  = XXH_rotl32(hash, 17) * XXH_PRIME32_4;     \
} while (0)

    if (ptr==NULL) XXH_ASSERT(len == 0);

    /* Compact rerolled version; generally faster */
    if (!XXH32_ENDJMP) {
        len &= 15;
        while (len >= 4) {
            XXH_PROCESS4;
            len -= 4;
        }
        while (len > 0) {
            XXH_PROCESS1;
            --len;
        }
        return XXH32_avalanche(hash);
    } else {
         switch(len&15) /* or switch(bEnd - p) */ {
           case 12:      XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 8:       XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 4:       XXH_PROCESS4;
                         return XXH32_avalanche(hash);

           case 13:      XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 9:       XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 5:       XXH_PROCESS4;
                         XXH_PROCESS1;
                         return XXH32_avalanche(hash);

           case 14:      XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 10:      XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 6:       XXH_PROCESS4;
                         XXH_PROCESS1;
                         XXH_PROCESS1;
                         return XXH32_avalanche(hash);

           case 15:      XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 11:      XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 7:       XXH_PROCESS4;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 3:       XXH_PROCESS1;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 2:       XXH_PROCESS1;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 1:       XXH_PROCESS1;
                         XXH_FALLTHROUGH;  /* fallthrough */
           case 0:       return XXH32_avalanche(hash);
        }
        XXH_ASSERT(0);
        return hash;   /* reaching this point is deemed impossible */
    }
}

#ifdef XXH_OLD_NAMES
#  define PROCESS1 XXH_PROCESS1
#  define PROCESS4 XXH_PROCESS4
#else
#  undef XXH_PROCESS1
#  undef XXH_PROCESS4
#endif

/*!
 * @internal
 * @brief The implementation for @ref XXH32().
 *
 * @param input , len , seed Directly passed from @ref XXH32().
 * @param align Whether @p input is aligned.
 * @return The calculated hash.
 */
XXH_FORCE_INLINE XXH_PUREF xxh_u32
XXH32_endian_align(const xxh_u8* input, size_t len, xxh_u32 seed, XXH_alignment align)
{
    xxh_u32 h32;

    if (input==NULL) XXH_ASSERT(len == 0);

    if (len>=16) {
        const xxh_u8* const bEnd = input + len;
        const xxh_u8* const limit = bEnd - 15;
        xxh_u32 v1 = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
        xxh_u32 v2 = seed + XXH_PRIME32_2;
        xxh_u32 v3 = seed + 0;
        xxh_u32 v4 = seed - XXH_PRIME32_1;

        do {
            v1 = XXH32_round(v1, XXH_get32bits(input)); input += 4;
            v2 = XXH32_round(v2, XXH_get32bits(input)); input += 4;
            v3 = XXH32_round(v3, XXH_get32bits(input)); input += 4;
            v4 = XXH32_round(v4, XXH_get32bits(input)); input += 4;
        } while (input < limit);

        h32 = XXH_rotl32(v1, 1)  + XXH_rotl32(v2, 7)
            + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
    } else {
        h32  = seed + XXH_PRIME32_5;
    }

    h32 += (xxh_u32)len;

    return XXH32_finalize(h32, input, len&15, align);
}

/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH32_hash_t XXH32 (const void* input, size_t len, XXH32_hash_t seed)
{
#if !defined(XXH_NO_STREAM) && XXH_SIZE_OPT >= 2
    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
    XXH32_state_t state;
    XXH32_reset(&state, seed);
    XXH32_update(&state, (const xxh_u8*)input, len);
    return XXH32_digest(&state);
#else
    if (XXH_FORCE_ALIGN_CHECK) {
        if ((((size_t)input) & 3) == 0) {   /* Input is 4-bytes aligned, leverage the speed benefit */
            return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
    }   }

    return XXH32_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);
#endif
}



/*******   Hash streaming   *******/
#ifndef XXH_NO_STREAM
/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH32_state_t* XXH32_createState(void)
{
    return (XXH32_state_t*)VG_(malloc)("zstddeclib.XXH32_createState.1", sizeof(XXH32_state_t));
}
/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH_errorcode XXH32_freeState(XXH32_state_t* statePtr)
{
    XXH_free(statePtr);
    return XXH_OK;
}

/*! @ingroup XXH32_family */
XXH_PUBLIC_API void XXH32_copyState(XXH32_state_t* dstState, const XXH32_state_t* srcState)
{
    XXH_memcpy(dstState, srcState, sizeof(*dstState));
}

/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH_errorcode XXH32_reset(XXH32_state_t* statePtr, XXH32_hash_t seed)
{
    XXH_ASSERT(statePtr != NULL);
    VG_(memset)(statePtr, 0, sizeof(*statePtr));
    statePtr->v[0] = seed + XXH_PRIME32_1 + XXH_PRIME32_2;
    statePtr->v[1] = seed + XXH_PRIME32_2;
    statePtr->v[2] = seed + 0;
    statePtr->v[3] = seed - XXH_PRIME32_1;
    return XXH_OK;
}


/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH_errorcode
XXH32_update(XXH32_state_t* state, const void* input, size_t len)
{
    if (input==NULL) {
        XXH_ASSERT(len == 0);
        return XXH_OK;
    }

    {   const xxh_u8* p = (const xxh_u8*)input;
        const xxh_u8* const bEnd = p + len;

        state->total_len_32 += (XXH32_hash_t)len;
        state->large_len |= (XXH32_hash_t)((len>=16) | (state->total_len_32>=16));

        if (state->memsize + len < 16)  {   /* fill in tmp buffer */
            XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, len);
            state->memsize += (XXH32_hash_t)len;
            return XXH_OK;
        }

        if (state->memsize) {   /* some data left from previous update */
            XXH_memcpy((xxh_u8*)(state->mem32) + state->memsize, input, 16-state->memsize);
            {   const xxh_u32* p32 = state->mem32;
                state->v[0] = XXH32_round(state->v[0], XXH_readLE32(p32)); p32++;
                state->v[1] = XXH32_round(state->v[1], XXH_readLE32(p32)); p32++;
                state->v[2] = XXH32_round(state->v[2], XXH_readLE32(p32)); p32++;
                state->v[3] = XXH32_round(state->v[3], XXH_readLE32(p32));
            }
            p += 16-state->memsize;
            state->memsize = 0;
        }

        if (p <= bEnd-16) {
            const xxh_u8* const limit = bEnd - 16;

            do {
                state->v[0] = XXH32_round(state->v[0], XXH_readLE32(p)); p+=4;
                state->v[1] = XXH32_round(state->v[1], XXH_readLE32(p)); p+=4;
                state->v[2] = XXH32_round(state->v[2], XXH_readLE32(p)); p+=4;
                state->v[3] = XXH32_round(state->v[3], XXH_readLE32(p)); p+=4;
            } while (p<=limit);

        }

        if (p < bEnd) {
            XXH_memcpy(state->mem32, p, (size_t)(bEnd-p));
            state->memsize = (unsigned)(bEnd-p);
        }
    }

    return XXH_OK;
}


/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH32_hash_t XXH32_digest(const XXH32_state_t* state)
{
    xxh_u32 h32;

    if (state->large_len) {
        h32 = XXH_rotl32(state->v[0], 1)
            + XXH_rotl32(state->v[1], 7)
            + XXH_rotl32(state->v[2], 12)
            + XXH_rotl32(state->v[3], 18);
    } else {
        h32 = state->v[2] /* == seed */ + XXH_PRIME32_5;
    }

    h32 += state->total_len_32;

    return XXH32_finalize(h32, (const xxh_u8*)state->mem32, state->memsize, XXH_aligned);
}
#endif /* !XXH_NO_STREAM */

/*******   Canonical representation   *******/

/*! @ingroup XXH32_family */
XXH_PUBLIC_API void XXH32_canonicalFromHash(XXH32_canonical_t* dst, XXH32_hash_t hash)
{
    XXH_STATIC_ASSERT(sizeof(XXH32_canonical_t) == sizeof(XXH32_hash_t));
    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap32(hash);
    XXH_memcpy(dst, &hash, sizeof(*dst));
}
/*! @ingroup XXH32_family */
XXH_PUBLIC_API XXH32_hash_t XXH32_hashFromCanonical(const XXH32_canonical_t* src)
{
    return XXH_readBE32(src);
}


#ifndef XXH_NO_LONG_LONG

/* *******************************************************************
*  64-bit hash functions
*********************************************************************/
/*!
 * @}
 * @ingroup impl
 * @{
 */
/*******   Memory access   *******/

typedef XXH64_hash_t xxh_u64;

#ifdef XXH_OLD_NAMES
#  define U64 xxh_u64
#endif

#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))
/*
 * Manual byteshift. Best for old compilers which don't inline memcpy.
 * We actually directly use XXH_readLE64 and XXH_readBE64.
 */
#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==2))

/* Force direct memory access. Only works on CPU which support unaligned memory access in hardware */
static xxh_u64 XXH_read64(const void* memPtr)
{
    return *(const xxh_u64*) memPtr;
}

#elif (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==1))

/*
 * __attribute__((aligned(1))) is supported by gcc and clang. Originally the
 * documentation claimed that it only increased the alignment, but actually it
 * can decrease it on gcc, clang, and icc:
 * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69502,
 * https://gcc.godbolt.org/z/xYez1j67Y.
 */
#ifdef XXH_OLD_NAMES
typedef union { xxh_u32 u32; xxh_u64 u64; } __attribute__((packed)) unalign64;
#endif
static xxh_u64 XXH_read64(const void* ptr)
{
    typedef __attribute__((aligned(1))) xxh_u64 xxh_unalign64;
    return *((const xxh_unalign64*)ptr);
}

#else

/*
 * Portable and safe solution. Generally efficient.
 * see: https://fastcompression.blogspot.com/2015/08/accessing-unaligned-memory.html
 */
static xxh_u64 XXH_read64(const void* memPtr)
{
    xxh_u64 val;
    XXH_memcpy(&val, memPtr, sizeof(val));
    return val;
}

#endif   /* XXH_FORCE_DIRECT_MEMORY_ACCESS */

#if defined(_MSC_VER)     /* Visual Studio */
#  define XXH_swap64 _byteswap_uint64
#elif XXH_GCC_VERSION >= 403
#  define XXH_swap64 __builtin_bswap64
#else
static xxh_u64 XXH_swap64(xxh_u64 x)
{
    return  ((x << 56) & 0xff00000000000000ULL) |
            ((x << 40) & 0x00ff000000000000ULL) |
            ((x << 24) & 0x0000ff0000000000ULL) |
            ((x << 8)  & 0x000000ff00000000ULL) |
            ((x >> 8)  & 0x00000000ff000000ULL) |
            ((x >> 24) & 0x0000000000ff0000ULL) |
            ((x >> 40) & 0x000000000000ff00ULL) |
            ((x >> 56) & 0x00000000000000ffULL);
}
#endif


/* XXH_FORCE_MEMORY_ACCESS==3 is an endian-independent byteshift load. */
#if (defined(XXH_FORCE_MEMORY_ACCESS) && (XXH_FORCE_MEMORY_ACCESS==3))

XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* memPtr)
{
    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
    return bytePtr[0]
         | ((xxh_u64)bytePtr[1] << 8)
         | ((xxh_u64)bytePtr[2] << 16)
         | ((xxh_u64)bytePtr[3] << 24)
         | ((xxh_u64)bytePtr[4] << 32)
         | ((xxh_u64)bytePtr[5] << 40)
         | ((xxh_u64)bytePtr[6] << 48)
         | ((xxh_u64)bytePtr[7] << 56);
}

XXH_FORCE_INLINE xxh_u64 XXH_readBE64(const void* memPtr)
{
    const xxh_u8* bytePtr = (const xxh_u8 *)memPtr;
    return bytePtr[7]
         | ((xxh_u64)bytePtr[6] << 8)
         | ((xxh_u64)bytePtr[5] << 16)
         | ((xxh_u64)bytePtr[4] << 24)
         | ((xxh_u64)bytePtr[3] << 32)
         | ((xxh_u64)bytePtr[2] << 40)
         | ((xxh_u64)bytePtr[1] << 48)
         | ((xxh_u64)bytePtr[0] << 56);
}

#else
XXH_FORCE_INLINE xxh_u64 XXH_readLE64(const void* ptr)
{
    return XXH_CPU_LITTLE_ENDIAN ? XXH_read64(ptr) : XXH_swap64(XXH_read64(ptr));
}

static xxh_u64 XXH_readBE64(const void* ptr)
{
    return XXH_CPU_LITTLE_ENDIAN ? XXH_swap64(XXH_read64(ptr)) : XXH_read64(ptr);
}
#endif

XXH_FORCE_INLINE xxh_u64
XXH_readLE64_align(const void* ptr, XXH_alignment align)
{
    if (align==XXH_unaligned)
        return XXH_readLE64(ptr);
    else
        return XXH_CPU_LITTLE_ENDIAN ? *(const xxh_u64*)ptr : XXH_swap64(*(const xxh_u64*)ptr);
}


/*******   xxh64   *******/
/*!
 * @}
 * @defgroup XXH64_impl XXH64 implementation
 * @ingroup impl
 *
 * Details on the XXH64 implementation.
 * @{
 */
/* #define rather that static const, to be used as initializers */
#define XXH_PRIME64_1  0x9E3779B185EBCA87ULL  /*!< 0b1001111000110111011110011011000110000101111010111100101010000111 */
#define XXH_PRIME64_2  0xC2B2AE3D27D4EB4FULL  /*!< 0b1100001010110010101011100011110100100111110101001110101101001111 */
#define XXH_PRIME64_3  0x165667B19E3779F9ULL  /*!< 0b0001011001010110011001111011000110011110001101110111100111111001 */
#define XXH_PRIME64_4  0x85EBCA77C2B2AE63ULL  /*!< 0b1000010111101011110010100111011111000010101100101010111001100011 */
#define XXH_PRIME64_5  0x27D4EB2F165667C5ULL  /*!< 0b0010011111010100111010110010111100010110010101100110011111000101 */

#ifdef XXH_OLD_NAMES
#  define PRIME64_1 XXH_PRIME64_1
#  define PRIME64_2 XXH_PRIME64_2
#  define PRIME64_3 XXH_PRIME64_3
#  define PRIME64_4 XXH_PRIME64_4
#  define PRIME64_5 XXH_PRIME64_5
#endif

/*! @copydoc XXH32_round */
static xxh_u64 XXH64_round(xxh_u64 acc, xxh_u64 input)
{
    acc += input * XXH_PRIME64_2;
    acc  = XXH_rotl64(acc, 31);
    acc *= XXH_PRIME64_1;
#if (defined(__AVX512F__)) && !defined(XXH_ENABLE_AUTOVECTORIZE)
    /*
     * DISABLE AUTOVECTORIZATION:
     * A compiler fence is used to prevent GCC and Clang from
     * autovectorizing the XXH64 loop (pragmas and attributes don't work for some
     * reason) without globally disabling AVX512.
     *
     * Autovectorization of XXH64 tends to be detrimental,
     * though the exact outcome may change depending on exact cpu and compiler version.
     * For information, it has been reported as detrimental for Skylake-X,
     * but possibly beneficial for Zen4.
     *
     * The default is to disable auto-vectorization,
     * but you can select to enable it instead using `XXH_ENABLE_AUTOVECTORIZE` build variable.
     */
    XXH_COMPILER_GUARD(acc);
#endif
    return acc;
}

static xxh_u64 XXH64_mergeRound(xxh_u64 acc, xxh_u64 val)
{
    val  = XXH64_round(0, val);
    acc ^= val;
    acc  = acc * XXH_PRIME64_1 + XXH_PRIME64_4;
    return acc;
}

/*! @copydoc XXH32_avalanche */
static xxh_u64 XXH64_avalanche(xxh_u64 hash)
{
    hash ^= hash >> 33;
    hash *= XXH_PRIME64_2;
    hash ^= hash >> 29;
    hash *= XXH_PRIME64_3;
    hash ^= hash >> 32;
    return hash;
}


#define XXH_get64bits(p) XXH_readLE64_align(p, align)

/*!
 * @internal
 * @brief Processes the last 0-31 bytes of @p ptr.
 *
 * There may be up to 31 bytes remaining to consume from the input.
 * This final stage will digest them to ensure that all input bytes are present
 * in the final mix.
 *
 * @param hash The hash to finalize.
 * @param ptr The pointer to the remaining input.
 * @param len The remaining length, modulo 32.
 * @param align Whether @p ptr is aligned.
 * @return The finalized hash
 * @see XXH32_finalize().
 */
static XXH_PUREF xxh_u64
XXH64_finalize(xxh_u64 hash, const xxh_u8* ptr, size_t len, XXH_alignment align)
{
    if (ptr==NULL) XXH_ASSERT(len == 0);
    len &= 31;
    while (len >= 8) {
        xxh_u64 const k1 = XXH64_round(0, XXH_get64bits(ptr));
        ptr += 8;
        hash ^= k1;
        hash  = XXH_rotl64(hash,27) * XXH_PRIME64_1 + XXH_PRIME64_4;
        len -= 8;
    }
    if (len >= 4) {
        hash ^= (xxh_u64)(XXH_get32bits(ptr)) * XXH_PRIME64_1;
        ptr += 4;
        hash = XXH_rotl64(hash, 23) * XXH_PRIME64_2 + XXH_PRIME64_3;
        len -= 4;
    }
    while (len > 0) {
        hash ^= (*ptr++) * XXH_PRIME64_5;
        hash = XXH_rotl64(hash, 11) * XXH_PRIME64_1;
        --len;
    }
    return  XXH64_avalanche(hash);
}

#ifdef XXH_OLD_NAMES
#  define PROCESS1_64 XXH_PROCESS1_64
#  define PROCESS4_64 XXH_PROCESS4_64
#  define PROCESS8_64 XXH_PROCESS8_64
#else
#  undef XXH_PROCESS1_64
#  undef XXH_PROCESS4_64
#  undef XXH_PROCESS8_64
#endif

/*!
 * @internal
 * @brief The implementation for @ref XXH64().
 *
 * @param input , len , seed Directly passed from @ref XXH64().
 * @param align Whether @p input is aligned.
 * @return The calculated hash.
 */
XXH_FORCE_INLINE XXH_PUREF xxh_u64
XXH64_endian_align(const xxh_u8* input, size_t len, xxh_u64 seed, XXH_alignment align)
{
    xxh_u64 h64;
    if (input==NULL) XXH_ASSERT(len == 0);

    if (len>=32) {
        const xxh_u8* const bEnd = input + len;
        const xxh_u8* const limit = bEnd - 31;
        xxh_u64 v1 = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
        xxh_u64 v2 = seed + XXH_PRIME64_2;
        xxh_u64 v3 = seed + 0;
        xxh_u64 v4 = seed - XXH_PRIME64_1;

        do {
            v1 = XXH64_round(v1, XXH_get64bits(input)); input+=8;
            v2 = XXH64_round(v2, XXH_get64bits(input)); input+=8;
            v3 = XXH64_round(v3, XXH_get64bits(input)); input+=8;
            v4 = XXH64_round(v4, XXH_get64bits(input)); input+=8;
        } while (input<limit);

        h64 = XXH_rotl64(v1, 1) + XXH_rotl64(v2, 7) + XXH_rotl64(v3, 12) + XXH_rotl64(v4, 18);
        h64 = XXH64_mergeRound(h64, v1);
        h64 = XXH64_mergeRound(h64, v2);
        h64 = XXH64_mergeRound(h64, v3);
        h64 = XXH64_mergeRound(h64, v4);

    } else {
        h64  = seed + XXH_PRIME64_5;
    }

    h64 += (xxh_u64) len;

    return XXH64_finalize(h64, input, len, align);
}


/*! @ingroup XXH64_family */
XXH_PUBLIC_API XXH64_hash_t XXH64 (XXH_NOESCAPE const void* input, size_t len, XXH64_hash_t seed)
{
#if !defined(XXH_NO_STREAM) && XXH_SIZE_OPT >= 2
    /* Simple version, good for code maintenance, but unfortunately slow for small inputs */
    XXH64_state_t state;
    XXH64_reset(&state, seed);
    XXH64_update(&state, (const xxh_u8*)input, len);
    return XXH64_digest(&state);
#else
    if (XXH_FORCE_ALIGN_CHECK) {
        if ((((size_t)input) & 7)==0) {  /* Input is aligned, let's leverage the speed advantage */
            return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_aligned);
    }   }

    return XXH64_endian_align((const xxh_u8*)input, len, seed, XXH_unaligned);

#endif
}

/*******   Hash Streaming   *******/
#ifndef XXH_NO_STREAM
/*! @ingroup XXH64_family*/
XXH_PUBLIC_API XXH64_state_t* XXH64_createState(void)
{
    return (XXH64_state_t*)VG_(malloc)("zstddeclib.XXH64_createState.1", sizeof(XXH64_state_t));
}
/*! @ingroup XXH64_family */
XXH_PUBLIC_API XXH_errorcode XXH64_freeState(XXH64_state_t* statePtr)
{
    XXH_free(statePtr);
    return XXH_OK;
}

/*! @ingroup XXH64_family */
XXH_PUBLIC_API void XXH64_copyState(XXH_NOESCAPE XXH64_state_t* dstState, const XXH64_state_t* srcState)
{
    XXH_memcpy(dstState, srcState, sizeof(*dstState));
}

/*! @ingroup XXH64_family */
XXH_PUBLIC_API XXH_errorcode XXH64_reset(XXH_NOESCAPE XXH64_state_t* statePtr, XXH64_hash_t seed)
{
    XXH_ASSERT(statePtr != NULL);
    VG_(memset)(statePtr, 0, sizeof(*statePtr));
    statePtr->v[0] = seed + XXH_PRIME64_1 + XXH_PRIME64_2;
    statePtr->v[1] = seed + XXH_PRIME64_2;
    statePtr->v[2] = seed + 0;
    statePtr->v[3] = seed - XXH_PRIME64_1;
    return XXH_OK;
}

/*! @ingroup XXH64_family */
XXH_PUBLIC_API XXH_errorcode
XXH64_update (XXH_NOESCAPE XXH64_state_t* state, XXH_NOESCAPE const void* input, size_t len)
{
    if (input==NULL) {
        XXH_ASSERT(len == 0);
        return XXH_OK;
    }

    {   const xxh_u8* p = (const xxh_u8*)input;
        const xxh_u8* const bEnd = p + len;

        state->total_len += len;

        if (state->memsize + len < 32) {  /* fill in tmp buffer */
            XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, len);
            state->memsize += (xxh_u32)len;
            return XXH_OK;
        }

        if (state->memsize) {   /* tmp buffer is full */
            XXH_memcpy(((xxh_u8*)state->mem64) + state->memsize, input, 32-state->memsize);
            state->v[0] = XXH64_round(state->v[0], XXH_readLE64(state->mem64+0));
            state->v[1] = XXH64_round(state->v[1], XXH_readLE64(state->mem64+1));
            state->v[2] = XXH64_round(state->v[2], XXH_readLE64(state->mem64+2));
            state->v[3] = XXH64_round(state->v[3], XXH_readLE64(state->mem64+3));
            p += 32 - state->memsize;
            state->memsize = 0;
        }

        if (p+32 <= bEnd) {
            const xxh_u8* const limit = bEnd - 32;

            do {
                state->v[0] = XXH64_round(state->v[0], XXH_readLE64(p)); p+=8;
                state->v[1] = XXH64_round(state->v[1], XXH_readLE64(p)); p+=8;
                state->v[2] = XXH64_round(state->v[2], XXH_readLE64(p)); p+=8;
                state->v[3] = XXH64_round(state->v[3], XXH_readLE64(p)); p+=8;
            } while (p<=limit);

        }

        if (p < bEnd) {
            XXH_memcpy(state->mem64, p, (size_t)(bEnd-p));
            state->memsize = (unsigned)(bEnd-p);
        }
    }

    return XXH_OK;
}


/*! @ingroup XXH64_family */
XXH_PUBLIC_API XXH64_hash_t XXH64_digest(XXH_NOESCAPE const XXH64_state_t* state)
{
    xxh_u64 h64;

    if (state->total_len >= 32) {
        h64 = XXH_rotl64(state->v[0], 1) + XXH_rotl64(state->v[1], 7) + XXH_rotl64(state->v[2], 12) + XXH_rotl64(state->v[3], 18);
        h64 = XXH64_mergeRound(h64, state->v[0]);
        h64 = XXH64_mergeRound(h64, state->v[1]);
        h64 = XXH64_mergeRound(h64, state->v[2]);
        h64 = XXH64_mergeRound(h64, state->v[3]);
    } else {
        h64  = state->v[2] /*seed*/ + XXH_PRIME64_5;
    }

    h64 += (xxh_u64) state->total_len;

    return XXH64_finalize(h64, (const xxh_u8*)state->mem64, (size_t)state->total_len, XXH_aligned);
}
#endif /* !XXH_NO_STREAM */

/******* Canonical representation   *******/

/*! @ingroup XXH64_family */
XXH_PUBLIC_API void XXH64_canonicalFromHash(XXH_NOESCAPE XXH64_canonical_t* dst, XXH64_hash_t hash)
{
    XXH_STATIC_ASSERT(sizeof(XXH64_canonical_t) == sizeof(XXH64_hash_t));
    if (XXH_CPU_LITTLE_ENDIAN) hash = XXH_swap64(hash);
    XXH_memcpy(dst, &hash, sizeof(*dst));
}

/*! @ingroup XXH64_family */
XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(XXH_NOESCAPE const XXH64_canonical_t* src)
{
    return XXH_readBE64(src);
}

#ifndef XXH_NO_XXH3

/* *********************************************************************
*  XXH3
*  New generation hash designed for speed on small keys and vectorization
************************************************************************ */
/*!
 * @}
 * @defgroup XXH3_impl XXH3 implementation
 * @ingroup impl
 * @{
 */

/* ===   Compiler specifics   === */

#if ((defined(sun) || defined(__sun)) && __cplusplus) /* Solaris includes __STDC_VERSION__ with C++. Tested with GCC 5.5 */
#  define XXH_RESTRICT   /* disable */
#elif defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* >= C99 */
#  define XXH_RESTRICT   restrict
#elif (defined (__GNUC__) && ((__GNUC__ > 3) || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))) \
   || (defined (__clang__)) \
   || (defined (_MSC_VER) && (_MSC_VER >= 1400)) \
   || (defined (__INTEL_COMPILER) && (__INTEL_COMPILER >= 1300))
/*
 * There are a LOT more compilers that recognize __restrict but this
 * covers the major ones.
 */
#  define XXH_RESTRICT   __restrict
#else
#  define XXH_RESTRICT   /* disable */
#endif

#if (defined(__GNUC__) && (__GNUC__ >= 3))  \
  || (defined(__INTEL_COMPILER) && (__INTEL_COMPILER >= 800)) \
  || defined(__clang__)
#    define XXH_likely(x) __builtin_expect(x, 1)
#    define XXH_unlikely(x) __builtin_expect(x, 0)
#else
#    define XXH_likely(x) (x)
#    define XXH_unlikely(x) (x)
#endif

#ifndef XXH_HAS_INCLUDE
#  ifdef __has_include
/*
 * Not defined as XXH_HAS_INCLUDE(x) (function-like) because
 * this causes segfaults in Apple Clang 4.2 (on Mac OS X 10.7 Lion)
 */
#    define XXH_HAS_INCLUDE __has_include
#  else
#    define XXH_HAS_INCLUDE(x) 0
#  endif
#endif

#if defined(__GNUC__) || defined(__clang__)
#  if defined(__ARM_FEATURE_SVE)
#    include <arm_sve.h>
#  endif
#  if defined(__ARM_NEON__) || defined(__ARM_NEON) \
   || (defined(_M_ARM) && _M_ARM >= 7) \
   || defined(_M_ARM64) || defined(_M_ARM64EC) \
   || (defined(__wasm_simd128__) && XXH_HAS_INCLUDE(<arm_neon.h>)) /* WASM SIMD128 via SIMDe */
#    define inline __inline__  /* circumvent a clang bug */
#    include <arm_neon.h>
#    undef inline
#  elif defined(__AVX2__)
#    include <immintrin.h>
#  elif defined(__SSE2__)
#    include <emmintrin.h>
#  endif
#endif

#if defined(_MSC_VER)
#  include <intrin.h>
#endif

/*
 * One goal of XXH3 is to make it fast on both 32-bit and 64-bit, while
 * remaining a true 64-bit/128-bit hash function.
 *
 * This is done by prioritizing a subset of 64-bit operations that can be
 * emulated without too many steps on the average 32-bit machine.
 *
 * For example, these two lines seem similar, and run equally fast on 64-bit:
 *
 *   xxh_u64 x;
 *   x ^= (x >> 47); // good
 *   x ^= (x >> 13); // bad
 *
 * However, to a 32-bit machine, there is a major difference.
 *
 * x ^= (x >> 47) looks like this:
 *
 *   x.lo ^= (x.hi >> (47 - 32));
 *
 * while x ^= (x >> 13) looks like this:
 *
 *   // note: funnel shifts are not usually cheap.
 *   x.lo ^= (x.lo >> 13) | (x.hi << (32 - 13));
 *   x.hi ^= (x.hi >> 13);
 *
 * The first one is significantly faster than the second, simply because the
 * shift is larger than 32. This means:
 *  - All the bits we need are in the upper 32 bits, so we can ignore the lower
 *    32 bits in the shift.
 *  - The shift result will always fit in the lower 32 bits, and therefore,
 *    we can ignore the upper 32 bits in the xor.
 *
 * Thanks to this optimization, XXH3 only requires these features to be efficient:
 *
 *  - Usable unaligned access
 *  - A 32-bit or 64-bit ALU
 *      - If 32-bit, a decent ADC instruction
 *  - A 32 or 64-bit multiply with a 64-bit result
 *  - For the 128-bit variant, a decent byteswap helps short inputs.
 *
 * The first two are already required by XXH32, and almost all 32-bit and 64-bit
 * platforms which can run XXH32 can run XXH3 efficiently.
 *
 * Thumb-1, the classic 16-bit only subset of ARM's instruction set, is one
 * notable exception.
 *
 * First of all, Thumb-1 lacks support for the UMULL instruction which
 * performs the important long multiply. This means numerous __aeabi_lmul
 * calls.
 *
 * Second of all, the 8 functional registers are just not enough.
 * Setup for __aeabi_lmul, byteshift loads, pointers, and all arithmetic need
 * Lo registers, and this shuffling results in thousands more MOVs than A32.
 *
 * A32 and T32 don't have this limitation. They can access all 14 registers,
 * do a 32->64 multiply with UMULL, and the flexible operand allowing free
 * shifts is helpful, too.
 *
 * Therefore, we do a quick sanity check.
 *
 * If compiling Thumb-1 for a target which supports ARM instructions, we will
 * emit a warning, as it is not a "sane" platform to compile for.
 *
 * Usually, if this happens, it is because of an accident and you probably need
 * to specify -march, as you likely meant to compile for a newer architecture.
 *
 * Credit: large sections of the vectorial and asm source code paths
 *         have been contributed by @easyaspi314
 */
#if defined(__thumb__) && !defined(__thumb2__) && defined(__ARM_ARCH_ISA_ARM)
#   warning "XXH3 is highly inefficient without ARM or Thumb-2."
#endif

/* ==========================================
 * Vectorization detection
 * ========================================== */

#ifdef XXH_DOXYGEN
/*!
 * @ingroup tuning
 * @brief Overrides the vectorization implementation chosen for XXH3.
 *
 * Can be defined to 0 to disable SIMD or any of the values mentioned in
 * @ref XXH_VECTOR_TYPE.
 *
 * If this is not defined, it uses predefined macros to determine the best
 * implementation.
 */
#  define XXH_VECTOR XXH_SCALAR
/*!
 * @ingroup tuning
 * @brief Possible values for @ref XXH_VECTOR.
 *
 * Note that these are actually implemented as macros.
 *
 * If this is not defined, it is detected automatically.
 * internal macro XXH_X86DISPATCH overrides this.
 */
enum XXH_VECTOR_TYPE /* fake enum */ {
    XXH_SCALAR = 0,  /*!< Portable scalar version */
    XXH_SSE2   = 1,  /*!<
                      * SSE2 for Pentium 4, Opteron, all x86_64.
                      *
                      * @note SSE2 is also guaranteed on Windows 10, macOS, and
                      * Android x86.
                      */
    XXH_AVX2   = 2,  /*!< AVX2 for Haswell and Bulldozer */
    XXH_AVX512 = 3,  /*!< AVX512 for Skylake and Icelake */
    XXH_NEON   = 4,  /*!<
                       * NEON for most ARMv7-A, all AArch64, and WASM SIMD128
                       * via the SIMDeverywhere polyfill provided with the
                       * Emscripten SDK.
                       */
    XXH_VSX    = 5,  /*!< VSX and ZVector for POWER8/z13 (64-bit) */
    XXH_SVE    = 6,  /*!< SVE for some ARMv8-A and ARMv9-A */
};
/*!
 * @ingroup tuning
 * @brief Selects the minimum alignment for XXH3's accumulators.
 *
 * When using SIMD, this should match the alignment required for said vector
 * type, so, for example, 32 for AVX2.
 *
 * Default: Auto detected.
 */
#  define XXH_ACC_ALIGN 8
#endif

/* Actual definition */
#ifndef XXH_DOXYGEN
#  define XXH_SCALAR 0
#  define XXH_SSE2   1
#  define XXH_AVX2   2
#  define XXH_AVX512 3
#  define XXH_NEON   4
#  define XXH_VSX    5
#  define XXH_SVE    6
#endif

#ifndef XXH_VECTOR    /* can be defined on command line */
#  if defined(__ARM_FEATURE_SVE)
#    define XXH_VECTOR XXH_SVE
#  elif ( \
        defined(__ARM_NEON__) || defined(__ARM_NEON) /* gcc */ \
     || defined(_M_ARM) || defined(_M_ARM64) || defined(_M_ARM64EC) /* msvc */ \
     || (defined(__wasm_simd128__) && XXH_HAS_INCLUDE(<arm_neon.h>)) /* wasm simd128 via SIMDe */ \
   ) && ( \
        defined(_WIN32) || defined(__LITTLE_ENDIAN__) /* little endian only */ \
    || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) \
   )
#    define XXH_VECTOR XXH_NEON
#  elif defined(__AVX512F__)
#    define XXH_VECTOR XXH_AVX512
#  elif defined(__AVX2__)
#    define XXH_VECTOR XXH_AVX2
#  elif defined(__SSE2__) || defined(_M_AMD64) || defined(_M_X64) || (defined(_M_IX86_FP) && (_M_IX86_FP == 2))
#    define XXH_VECTOR XXH_SSE2
#  elif (defined(__PPC64__) && defined(__POWER8_VECTOR__)) \
     || (defined(__s390x__) && defined(__VEC__)) \
     && defined(__GNUC__) /* TODO: IBM XL */
#    define XXH_VECTOR XXH_VSX
#  else
#    define XXH_VECTOR XXH_SCALAR
#  endif
#endif

/* __ARM_FEATURE_SVE is only supported by GCC & Clang. */
#if (XXH_VECTOR == XXH_SVE) && !defined(__ARM_FEATURE_SVE)
#  ifdef _MSC_VER
#    pragma warning(once : 4606)
#  else
#    warning "__ARM_FEATURE_SVE isn't supported. Use SCALAR instead."
#  endif
#  undef XXH_VECTOR
#  define XXH_VECTOR XXH_SCALAR
#endif

/*
 * Controls the alignment of the accumulator,
 * for compatibility with aligned vector loads, which are usually faster.
 */
#ifndef XXH_ACC_ALIGN
#  if defined(XXH_X86DISPATCH)
#     define XXH_ACC_ALIGN 64  /* for compatibility with avx512 */
#  elif XXH_VECTOR == XXH_SCALAR  /* scalar */
#     define XXH_ACC_ALIGN 8
#  elif XXH_VECTOR == XXH_SSE2  /* sse2 */
#     define XXH_ACC_ALIGN 16
#  elif XXH_VECTOR == XXH_AVX2  /* avx2 */
#     define XXH_ACC_ALIGN 32
#  elif XXH_VECTOR == XXH_NEON  /* neon */
#     define XXH_ACC_ALIGN 16
#  elif XXH_VECTOR == XXH_VSX   /* vsx */
#     define XXH_ACC_ALIGN 16
#  elif XXH_VECTOR == XXH_AVX512  /* avx512 */
#     define XXH_ACC_ALIGN 64
#  elif XXH_VECTOR == XXH_SVE   /* sve */
#     define XXH_ACC_ALIGN 64
#  endif
#endif

#if defined(XXH_X86DISPATCH) || XXH_VECTOR == XXH_SSE2 \
    || XXH_VECTOR == XXH_AVX2 || XXH_VECTOR == XXH_AVX512
#  define XXH_SEC_ALIGN XXH_ACC_ALIGN
#elif XXH_VECTOR == XXH_SVE
#  define XXH_SEC_ALIGN XXH_ACC_ALIGN
#else
#  define XXH_SEC_ALIGN 8
#endif

#if defined(__GNUC__) || defined(__clang__)
#  define XXH_ALIASING __attribute__((may_alias))
#else
#  define XXH_ALIASING /* nothing */
#endif

/*
 * UGLY HACK:
 * GCC usually generates the best code with -O3 for xxHash.
 *
 * However, when targeting AVX2, it is overzealous in its unrolling resulting
 * in code roughly 3/4 the speed of Clang.
 *
 * There are other issues, such as GCC splitting _mm256_loadu_si256 into
 * _mm_loadu_si128 + _mm256_inserti128_si256. This is an optimization which
 * only applies to Sandy and Ivy Bridge... which don't even support AVX2.
 *
 * That is why when compiling the AVX2 version, it is recommended to use either
 *   -O2 -mavx2 -march=haswell
 * or
 *   -O2 -mavx2 -mno-avx256-split-unaligned-load
 * for decent performance, or to use Clang instead.
 *
 * Fortunately, we can control the first one with a pragma that forces GCC into
 * -O2, but the other one we can't control without "failed to inline always
 * inline function due to target mismatch" warnings.
 */
#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
  && defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
  && defined(__OPTIMIZE__) && XXH_SIZE_OPT <= 0 /* respect -O0 and -Os */
#  pragma GCC push_options
#  pragma GCC optimize("-O2")
#endif

#if XXH_VECTOR == XXH_NEON

/*
 * UGLY HACK: While AArch64 GCC on Linux does not seem to care, on macOS, GCC -O3
 * optimizes out the entire hashLong loop because of the aliasing violation.
 *
 * However, GCC is also inefficient at load-store optimization with vld1q/vst1q,
 * so the only option is to mark it as aliasing.
 */
typedef uint64x2_t xxh_aliasing_uint64x2_t XXH_ALIASING;

/*!
 * @internal
 * @brief `vld1q_u64` but faster and alignment-safe.
 *
 * On AArch64, unaligned access is always safe, but on ARMv7-a, it is only
 * *conditionally* safe (`vld1` has an alignment bit like `movdq[ua]` in x86).
 *
 * GCC for AArch64 sees `vld1q_u8` as an intrinsic instead of a load, so it
 * prohibits load-store optimizations. Therefore, a direct dereference is used.
 *
 * Otherwise, `vld1q_u8` is used with `vreinterpretq_u8_u64` to do a safe
 * unaligned load.
 */
#if defined(__aarch64__) && defined(__GNUC__) && !defined(__clang__)
XXH_FORCE_INLINE uint64x2_t XXH_vld1q_u64(void const* ptr) /* silence -Wcast-align */
{
    return *(xxh_aliasing_uint64x2_t const *)ptr;
}
#else
XXH_FORCE_INLINE uint64x2_t XXH_vld1q_u64(void const* ptr)
{
    return vreinterpretq_u64_u8(vld1q_u8((uint8_t const*)ptr));
}
#endif

/*!
 * @internal
 * @brief `vmlal_u32` on low and high halves of a vector.
 *
 * This is a workaround for AArch64 GCC < 11 which implemented arm_neon.h with
 * inline assembly and were therefore incapable of merging the `vget_{low, high}_u32`
 * with `vmlal_u32`.
 */
#if defined(__aarch64__) && defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 11
XXH_FORCE_INLINE uint64x2_t
XXH_vmlal_low_u32(uint64x2_t acc, uint32x4_t lhs, uint32x4_t rhs)
{
    /* Inline assembly is the only way */
    __asm__("umlal   %0.2d, %1.2s, %2.2s" : "+w" (acc) : "w" (lhs), "w" (rhs));
    return acc;
}
XXH_FORCE_INLINE uint64x2_t
XXH_vmlal_high_u32(uint64x2_t acc, uint32x4_t lhs, uint32x4_t rhs)
{
    /* This intrinsic works as expected */
    return vmlal_high_u32(acc, lhs, rhs);
}
#else
/* Portable intrinsic versions */
XXH_FORCE_INLINE uint64x2_t
XXH_vmlal_low_u32(uint64x2_t acc, uint32x4_t lhs, uint32x4_t rhs)
{
    return vmlal_u32(acc, vget_low_u32(lhs), vget_low_u32(rhs));
}
/*! @copydoc XXH_vmlal_low_u32
 * Assume the compiler converts this to vmlal_high_u32 on aarch64 */
XXH_FORCE_INLINE uint64x2_t
XXH_vmlal_high_u32(uint64x2_t acc, uint32x4_t lhs, uint32x4_t rhs)
{
    return vmlal_u32(acc, vget_high_u32(lhs), vget_high_u32(rhs));
}
#endif

/*!
 * @ingroup tuning
 * @brief Controls the NEON to scalar ratio for XXH3
 *
 * This can be set to 2, 4, 6, or 8.
 *
 * ARM Cortex CPUs are _very_ sensitive to how their pipelines are used.
 *
 * For example, the Cortex-A73 can dispatch 3 micro-ops per cycle, but only 2 of those
 * can be NEON. If you are only using NEON instructions, you are only using 2/3 of the CPU
 * bandwidth.
 *
 * This is even more noticeable on the more advanced cores like the Cortex-A76 which
 * can dispatch 8 micro-ops per cycle, but still only 2 NEON micro-ops at once.
 *
 * Therefore, to make the most out of the pipeline, it is beneficial to run 6 NEON lanes
 * and 2 scalar lanes, which is chosen by default.
 *
 * This does not apply to Apple processors or 32-bit processors, which run better with
 * full NEON. These will default to 8. Additionally, size-optimized builds run 8 lanes.
 *
 * This change benefits CPUs with large micro-op buffers without negatively affecting
 * most other CPUs:
 *
 *  | Chipset               | Dispatch type       | NEON only | 6:2 hybrid | Diff. |
 *  |:----------------------|:--------------------|----------:|-----------:|------:|
 *  | Snapdragon 730 (A76)  | 2 NEON/8 micro-ops  |  8.8 GB/s |  10.1 GB/s |  ~16% |
 *  | Snapdragon 835 (A73)  | 2 NEON/3 micro-ops  |  5.1 GB/s |   5.3 GB/s |   ~5% |
 *  | Marvell PXA1928 (A53) | In-order dual-issue |  1.9 GB/s |   1.9 GB/s |    0% |
 *  | Apple M1              | 4 NEON/8 micro-ops  | 37.3 GB/s |  36.1 GB/s |  ~-3% |
 *
 * It also seems to fix some bad codegen on GCC, making it almost as fast as clang.
 *
 * When using WASM SIMD128, if this is 2 or 6, SIMDe will scalarize 2 of the lanes meaning
 * it effectively becomes worse 4.
 *
 * @see XXH3_accumulate_512_neon()
 */
# ifndef XXH3_NEON_LANES
#  if (defined(__aarch64__) || defined(__arm64__) || defined(_M_ARM64) || defined(_M_ARM64EC)) \
   && !defined(__APPLE__) && XXH_SIZE_OPT <= 0
#   define XXH3_NEON_LANES 6
#  else
#   define XXH3_NEON_LANES XXH_ACC_NB
#  endif
# endif
#endif  /* XXH_VECTOR == XXH_NEON */

/*
 * VSX and Z Vector helpers.
 *
 * This is very messy, and any pull requests to clean this up are welcome.
 *
 * There are a lot of problems with supporting VSX and s390x, due to
 * inconsistent intrinsics, spotty coverage, and multiple endiannesses.
 */
#if XXH_VECTOR == XXH_VSX
/* Annoyingly, these headers _may_ define three macros: `bool`, `vector`,
 * and `pixel`. This is a problem for obvious reasons.
 *
 * These keywords are unnecessary; the spec literally says they are
 * equivalent to `__bool`, `__vector`, and `__pixel` and may be undef'd
 * after including the header.
 *
 * We use pragma push_macro/pop_macro to keep the namespace clean. */
#  pragma push_macro("bool")
#  pragma push_macro("vector")
#  pragma push_macro("pixel")
/* silence potential macro redefined warnings */
#  undef bool
#  undef vector
#  undef pixel

#  if defined(__s390x__)
#    include <s390intrin.h>
#  else
#    include <altivec.h>
#  endif

/* Restore the original macro values, if applicable. */
#  pragma pop_macro("pixel")
#  pragma pop_macro("vector")
#  pragma pop_macro("bool")

typedef __vector unsigned long long xxh_u64x2;
typedef __vector unsigned char xxh_u8x16;
typedef __vector unsigned xxh_u32x4;

/*
 * UGLY HACK: Similar to aarch64 macOS GCC, s390x GCC has the same aliasing issue.
 */
typedef xxh_u64x2 xxh_aliasing_u64x2 XXH_ALIASING;

# ifndef XXH_VSX_BE
#  if defined(__BIG_ENDIAN__) \
  || (defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
#    define XXH_VSX_BE 1
#  elif defined(__VEC_ELEMENT_REG_ORDER__) && __VEC_ELEMENT_REG_ORDER__ == __ORDER_BIG_ENDIAN__
#    warning "-maltivec=be is not recommended. Please use native endianness."
#    define XXH_VSX_BE 1
#  else
#    define XXH_VSX_BE 0
#  endif
# endif /* !defined(XXH_VSX_BE) */

# if XXH_VSX_BE
#  if defined(__POWER9_VECTOR__) || (defined(__clang__) && defined(__s390x__))
#    define XXH_vec_revb vec_revb
#  else
/*!
 * A polyfill for POWER9's vec_revb().
 */
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_revb(xxh_u64x2 val)
{
    xxh_u8x16 const vByteSwap = { 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01, 0x00,
                                  0x0F, 0x0E, 0x0D, 0x0C, 0x0B, 0x0A, 0x09, 0x08 };
    return vec_perm(val, val, vByteSwap);
}
#  endif
# endif /* XXH_VSX_BE */

/*!
 * Performs an unaligned vector load and byte swaps it on big endian.
 */
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_loadu(const void *ptr)
{
    xxh_u64x2 ret;
    XXH_memcpy(&ret, ptr, sizeof(xxh_u64x2));
# if XXH_VSX_BE
    ret = XXH_vec_revb(ret);
# endif
    return ret;
}

/*
 * vec_mulo and vec_mule are very problematic intrinsics on PowerPC
 *
 * These intrinsics weren't added until GCC 8, despite existing for a while,
 * and they are endian dependent. Also, their meaning swap depending on version.
 * */
# if defined(__s390x__)
 /* s390x is always big endian, no issue on this platform */
#  define XXH_vec_mulo vec_mulo
#  define XXH_vec_mule vec_mule
# elif defined(__clang__) && XXH_HAS_BUILTIN(__builtin_altivec_vmuleuw) && !defined(__ibmxl__)
/* Clang has a better way to control this, we can just use the builtin which doesn't swap. */
 /* The IBM XL Compiler (which defined __clang__) only implements the vec_* operations */
#  define XXH_vec_mulo __builtin_altivec_vmulouw
#  define XXH_vec_mule __builtin_altivec_vmuleuw
# else
/* gcc needs inline assembly */
/* Adapted from https://github.com/google/highwayhash/blob/master/highwayhash/hh_vsx.h. */
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mulo(xxh_u32x4 a, xxh_u32x4 b)
{
    xxh_u64x2 result;
    __asm__("vmulouw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
    return result;
}
XXH_FORCE_INLINE xxh_u64x2 XXH_vec_mule(xxh_u32x4 a, xxh_u32x4 b)
{
    xxh_u64x2 result;
    __asm__("vmuleuw %0, %1, %2" : "=v" (result) : "v" (a), "v" (b));
    return result;
}
# endif /* XXH_vec_mulo, XXH_vec_mule */
#endif /* XXH_VECTOR == XXH_VSX */

#if XXH_VECTOR == XXH_SVE
#define ACCRND(acc, offset) \
do { \
    svuint64_t input_vec = svld1_u64(mask, xinput + offset);         \
    svuint64_t secret_vec = svld1_u64(mask, xsecret + offset);       \
    svuint64_t mixed = sveor_u64_x(mask, secret_vec, input_vec);     \
    svuint64_t swapped = svtbl_u64(input_vec, kSwap);                \
    svuint64_t mixed_lo = svextw_u64_x(mask, mixed);                 \
    svuint64_t mixed_hi = svlsr_n_u64_x(mask, mixed, 32);            \
    svuint64_t mul = svmad_u64_x(mask, mixed_lo, mixed_hi, swapped); \
    acc = svadd_u64_x(mask, acc, mul);                               \
} while (0)
#endif /* XXH_VECTOR == XXH_SVE */

/* prefetch
 * can be disabled, by declaring XXH_NO_PREFETCH build macro */
#if defined(XXH_NO_PREFETCH)
#  define XXH_PREFETCH(ptr)  (void)(ptr)  /* disabled */
#else
#  if XXH_SIZE_OPT >= 1
#    define XXH_PREFETCH(ptr) (void)(ptr)
#  elif defined(_MSC_VER) && (defined(_M_X64) || defined(_M_IX86))  /* _mm_prefetch() not defined outside of x86/x64 */
#    include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
#    define XXH_PREFETCH(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
#  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
#    define XXH_PREFETCH(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
#  else
#    define XXH_PREFETCH(ptr) (void)(ptr)  /* disabled */
#  endif
#endif  /* XXH_NO_PREFETCH */


/* ==========================================
 * XXH3 default settings
 * ========================================== */

#define XXH_SECRET_DEFAULT_SIZE 192   /* minimum XXH3_SECRET_SIZE_MIN */

#if (XXH_SECRET_DEFAULT_SIZE < XXH3_SECRET_SIZE_MIN)
#  error "default keyset is not large enough"
#endif

/*! Pseudorandom secret taken directly from FARSH. */
XXH_ALIGN(64) static const xxh_u8 XXH3_kSecret[XXH_SECRET_DEFAULT_SIZE] = {
    0xb8, 0xfe, 0x6c, 0x39, 0x23, 0xa4, 0x4b, 0xbe, 0x7c, 0x01, 0x81, 0x2c, 0xf7, 0x21, 0xad, 0x1c,
    0xde, 0xd4, 0x6d, 0xe9, 0x83, 0x90, 0x97, 0xdb, 0x72, 0x40, 0xa4, 0xa4, 0xb7, 0xb3, 0x67, 0x1f,
    0xcb, 0x79, 0xe6, 0x4e, 0xcc, 0xc0, 0xe5, 0x78, 0x82, 0x5a, 0xd0, 0x7d, 0xcc, 0xff, 0x72, 0x21,
    0xb8, 0x08, 0x46, 0x74, 0xf7, 0x43, 0x24, 0x8e, 0xe0, 0x35, 0x90, 0xe6, 0x81, 0x3a, 0x26, 0x4c,
    0x3c, 0x28, 0x52, 0xbb, 0x91, 0xc3, 0x00, 0xcb, 0x88, 0xd0, 0x65, 0x8b, 0x1b, 0x53, 0x2e, 0xa3,
    0x71, 0x64, 0x48, 0x97, 0xa2, 0x0d, 0xf9, 0x4e, 0x38, 0x19, 0xef, 0x46, 0xa9, 0xde, 0xac, 0xd8,
    0xa8, 0xfa, 0x76, 0x3f, 0xe3, 0x9c, 0x34, 0x3f, 0xf9, 0xdc, 0xbb, 0xc7, 0xc7, 0x0b, 0x4f, 0x1d,
    0x8a, 0x51, 0xe0, 0x4b, 0xcd, 0xb4, 0x59, 0x31, 0xc8, 0x9f, 0x7e, 0xc9, 0xd9, 0x78, 0x73, 0x64,
    0xea, 0xc5, 0xac, 0x83, 0x34, 0xd3, 0xeb, 0xc3, 0xc5, 0x81, 0xa0, 0xff, 0xfa, 0x13, 0x63, 0xeb,
    0x17, 0x0d, 0xdd, 0x51, 0xb7, 0xf0, 0xda, 0x49, 0xd3, 0x16, 0x55, 0x26, 0x29, 0xd4, 0x68, 0x9e,
    0x2b, 0x16, 0xbe, 0x58, 0x7d, 0x47, 0xa1, 0xfc, 0x8f, 0xf8, 0xb8, 0xd1, 0x7a, 0xd0, 0x31, 0xce,
    0x45, 0xcb, 0x3a, 0x8f, 0x95, 0x16, 0x04, 0x28, 0xaf, 0xd7, 0xfb, 0xca, 0xbb, 0x4b, 0x40, 0x7e,
};

static const xxh_u64 PRIME_MX1 = 0x165667919E3779F9ULL;  /*!< 0b0001011001010110011001111001000110011110001101110111100111111001 */
static const xxh_u64 PRIME_MX2 = 0x9FB21C651E98DF25ULL;  /*!< 0b1001111110110010000111000110010100011110100110001101111100100101 */

#ifdef XXH_OLD_NAMES
#  define kSecret XXH3_kSecret
#endif

#ifdef XXH_DOXYGEN
/*!
 * @brief Calculates a 32-bit to 64-bit long multiply.
 *
 * Implemented as a macro.
 *
 * Wraps `__emulu` on MSVC x86 because it tends to call `__allmul` when it doesn't
 * need to (but it shouldn't need to anyways, it is about 7 instructions to do
 * a 64x64 multiply...). Since we know that this will _always_ emit `MULL`, we
 * use that instead of the normal method.
 *
 * If you are compiling for platforms like Thumb-1 and don't have a better option,
 * you may also want to write your own long multiply routine here.
 *
 * @param x, y Numbers to be multiplied
 * @return 64-bit product of the low 32 bits of @p x and @p y.
 */
XXH_FORCE_INLINE xxh_u64
XXH_mult32to64(xxh_u64 x, xxh_u64 y)
{
   return (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF);
}
#elif defined(_MSC_VER) && defined(_M_IX86)
#    define XXH_mult32to64(x, y) __emulu((unsigned)(x), (unsigned)(y))
#else
/*
 * Downcast + upcast is usually better than masking on older compilers like
 * GCC 4.2 (especially 32-bit ones), all without affecting newer compilers.
 *
 * The other method, (x & 0xFFFFFFFF) * (y & 0xFFFFFFFF), will AND both operands
 * and perform a full 64x64 multiply -- entirely redundant on 32-bit.
 */
#    define XXH_mult32to64(x, y) ((xxh_u64)(xxh_u32)(x) * (xxh_u64)(xxh_u32)(y))
#endif

/*!
 * @brief Calculates a 64->128-bit long multiply.
 *
 * Uses `__uint128_t` and `_umul128` if available, otherwise uses a scalar
 * version.
 *
 * @param lhs , rhs The 64-bit integers to be multiplied
 * @return The 128-bit result represented in an @ref XXH128_hash_t.
 */
static XXH128_hash_t
XXH_mult64to128(xxh_u64 lhs, xxh_u64 rhs)
{
    /*
     * GCC/Clang __uint128_t method.
     *
     * On most 64-bit targets, GCC and Clang define a __uint128_t type.
     * This is usually the best way as it usually uses a native long 64-bit
     * multiply, such as MULQ on x86_64 or MUL + UMULH on aarch64.
     *
     * Usually.
     *
     * Despite being a 32-bit platform, Clang (and emscripten) define this type
     * despite not having the arithmetic for it. This results in a laggy
     * compiler builtin call which calculates a full 128-bit multiply.
     * In that case it is best to use the portable one.
     * https://github.com/Cyan4973/xxHash/issues/211#issuecomment-515575677
     */
#if (defined(__GNUC__) || defined(__clang__)) && !defined(__wasm__) \
    && defined(__SIZEOF_INT128__) \
    || (defined(_INTEGRAL_MAX_BITS) && _INTEGRAL_MAX_BITS >= 128)

    __uint128_t const product = (__uint128_t)lhs * (__uint128_t)rhs;
    XXH128_hash_t r128;
    r128.low64  = (xxh_u64)(product);
    r128.high64 = (xxh_u64)(product >> 64);
    return r128;

    /*
     * MSVC for x64's _umul128 method.
     *
     * xxh_u64 _umul128(xxh_u64 Multiplier, xxh_u64 Multiplicand, xxh_u64 *HighProduct);
     *
     * This compiles to single operand MUL on x64.
     */
#elif (defined(_M_X64) || defined(_M_IA64)) && !defined(_M_ARM64EC)

#ifndef _MSC_VER
#   pragma intrinsic(_umul128)
#endif
    xxh_u64 product_high;
    xxh_u64 const product_low = _umul128(lhs, rhs, &product_high);
    XXH128_hash_t r128;
    r128.low64  = product_low;
    r128.high64 = product_high;
    return r128;

    /*
     * MSVC for ARM64's __umulh method.
     *
     * This compiles to the same MUL + UMULH as GCC/Clang's __uint128_t method.
     */
#elif defined(_M_ARM64) || defined(_M_ARM64EC)

#ifndef _MSC_VER
#   pragma intrinsic(__umulh)
#endif
    XXH128_hash_t r128;
    r128.low64  = lhs * rhs;
    r128.high64 = __umulh(lhs, rhs);
    return r128;

#else
    /*
     * Portable scalar method. Optimized for 32-bit and 64-bit ALUs.
     *
     * This is a fast and simple grade school multiply, which is shown below
     * with base 10 arithmetic instead of base 0x100000000.
     *
     *           9 3 // D2 lhs = 93
     *         x 7 5 // D2 rhs = 75
     *     ----------
     *           1 5 // D2 lo_lo = (93 % 10) * (75 % 10) = 15
     *         4 5 | // D2 hi_lo = (93 / 10) * (75 % 10) = 45
     *         2 1 | // D2 lo_hi = (93 % 10) * (75 / 10) = 21
     *     + 6 3 | | // D2 hi_hi = (93 / 10) * (75 / 10) = 63
     *     ---------
     *         2 7 | // D2 cross = (15 / 10) + (45 % 10) + 21 = 27
     *     + 6 7 | | // D2 upper = (27 / 10) + (45 / 10) + 63 = 67
     *     ---------
     *       6 9 7 5 // D4 res = (27 * 10) + (15 % 10) + (67 * 100) = 6975
     *
     * The reasons for adding the products like this are:
     *  1. It avoids manual carry tracking. Just like how
     *     (9 * 9) + 9 + 9 = 99, the same applies with this for UINT64_MAX.
     *     This avoids a lot of complexity.
     *
     *  2. It hints for, and on Clang, compiles to, the powerful UMAAL
     *     instruction available in ARM's Digital Signal Processing extension
     *     in 32-bit ARMv6 and later, which is shown below:
     *
     *         void UMAAL(xxh_u32 *RdLo, xxh_u32 *RdHi, xxh_u32 Rn, xxh_u32 Rm)
     *         {
     *             xxh_u64 product = (xxh_u64)*RdLo * (xxh_u64)*RdHi + Rn + Rm;
     *             *RdLo = (xxh_u32)(product & 0xFFFFFFFF);
     *             *RdHi = (xxh_u32)(product >> 32);
     *         }
     *
     *     This instruction was designed for efficient long multiplication, and
     *     allows this to be calculated in only 4 instructions at speeds
     *     comparable to some 64-bit ALUs.
     *
     *  3. It isn't terrible on other platforms. Usually this will be a couple
     *     of 32-bit ADD/ADCs.
     */

    /* First calculate all of the cross products. */
    xxh_u64 const lo_lo = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs & 0xFFFFFFFF);
    xxh_u64 const hi_lo = XXH_mult32to64(lhs >> 32,        rhs & 0xFFFFFFFF);
    xxh_u64 const lo_hi = XXH_mult32to64(lhs & 0xFFFFFFFF, rhs >> 32);
    xxh_u64 const hi_hi = XXH_mult32to64(lhs >> 32,        rhs >> 32);

    /* Now add the products together. These will never overflow. */
    xxh_u64 const cross = (lo_lo >> 32) + (hi_lo & 0xFFFFFFFF) + lo_hi;
    xxh_u64 const upper = (hi_lo >> 32) + (cross >> 32)        + hi_hi;
    xxh_u64 const lower = (cross << 32) | (lo_lo & 0xFFFFFFFF);

    XXH128_hash_t r128;
    r128.low64  = lower;
    r128.high64 = upper;
    return r128;
#endif
}

/*!
 * @brief Calculates a 64-bit to 128-bit multiply, then XOR folds it.
 *
 * The reason for the separate function is to prevent passing too many structs
 * around by value. This will hopefully inline the multiply, but we don't force it.
 *
 * @param lhs , rhs The 64-bit integers to multiply
 * @return The low 64 bits of the product XOR'd by the high 64 bits.
 * @see XXH_mult64to128()
 */
static xxh_u64
XXH3_mul128_fold64(xxh_u64 lhs, xxh_u64 rhs)
{
    XXH128_hash_t product = XXH_mult64to128(lhs, rhs);
    return product.low64 ^ product.high64;
}

/*! Seems to produce slightly better code on GCC for some reason. */
XXH_FORCE_INLINE XXH_CONSTF xxh_u64 XXH_xorshift64(xxh_u64 v64, int shift)
{
    XXH_ASSERT(0 <= shift && shift < 64);
    return v64 ^ (v64 >> shift);
}

/*
 * This is a fast avalanche stage,
 * suitable when input bits are already partially mixed
 */
static XXH64_hash_t XXH3_avalanche(xxh_u64 h64)
{
    h64 = XXH_xorshift64(h64, 37);
    h64 *= PRIME_MX1;
    h64 = XXH_xorshift64(h64, 32);
    return h64;
}

/*
 * This is a stronger avalanche,
 * inspired by Pelle Evensen's rrmxmx
 * preferable when input has not been previously mixed
 */
static XXH64_hash_t XXH3_rrmxmx(xxh_u64 h64, xxh_u64 len)
{
    /* this mix is inspired by Pelle Evensen's rrmxmx */
    h64 ^= XXH_rotl64(h64, 49) ^ XXH_rotl64(h64, 24);
    h64 *= PRIME_MX2;
    h64 ^= (h64 >> 35) + len ;
    h64 *= PRIME_MX2;
    return XXH_xorshift64(h64, 28);
}


/* ==========================================
 * Short keys
 * ==========================================
 * One of the shortcomings of XXH32 and XXH64 was that their performance was
 * sub-optimal on short lengths. It used an iterative algorithm which strongly
 * favored lengths that were a multiple of 4 or 8.
 *
 * Instead of iterating over individual inputs, we use a set of single shot
 * functions which piece together a range of lengths and operate in constant time.
 *
 * Additionally, the number of multiplies has been significantly reduced. This
 * reduces latency, especially when emulating 64-bit multiplies on 32-bit.
 *
 * Depending on the platform, this may or may not be faster than XXH32, but it
 * is almost guaranteed to be faster than XXH64.
 */

/*
 * At very short lengths, there isn't enough input to fully hide secrets, or use
 * the entire secret.
 *
 * There is also only a limited amount of mixing we can do before significantly
 * impacting performance.
 *
 * Therefore, we use different sections of the secret and always mix two secret
 * samples with an XOR. This should have no effect on performance on the
 * seedless or withSeed variants because everything _should_ be constant folded
 * by modern compilers.
 *
 * The XOR mixing hides individual parts of the secret and increases entropy.
 *
 * This adds an extra layer of strength for custom secrets.
 */
XXH_FORCE_INLINE XXH_PUREF XXH64_hash_t
XXH3_len_1to3_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(input != NULL);
    XXH_ASSERT(1 <= len && len <= 3);
    XXH_ASSERT(secret != NULL);
    /*
     * len = 1: combined = { input[0], 0x01, input[0], input[0] }
     * len = 2: combined = { input[1], 0x02, input[0], input[1] }
     * len = 3: combined = { input[2], 0x03, input[0], input[1] }
     */
    {   xxh_u8  const c1 = input[0];
        xxh_u8  const c2 = input[len >> 1];
        xxh_u8  const c3 = input[len - 1];
        xxh_u32 const combined = ((xxh_u32)c1 << 16) | ((xxh_u32)c2  << 24)
                               | ((xxh_u32)c3 <<  0) | ((xxh_u32)len << 8);
        xxh_u64 const bitflip = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
        xxh_u64 const keyed = (xxh_u64)combined ^ bitflip;
        return XXH64_avalanche(keyed);
    }
}

XXH_FORCE_INLINE XXH_PUREF XXH64_hash_t
XXH3_len_4to8_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(input != NULL);
    XXH_ASSERT(secret != NULL);
    XXH_ASSERT(4 <= len && len <= 8);
    seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
    {   xxh_u32 const input1 = XXH_readLE32(input);
        xxh_u32 const input2 = XXH_readLE32(input + len - 4);
        xxh_u64 const bitflip = (XXH_readLE64(secret+8) ^ XXH_readLE64(secret+16)) - seed;
        xxh_u64 const input64 = input2 + (((xxh_u64)input1) << 32);
        xxh_u64 const keyed = input64 ^ bitflip;
        return XXH3_rrmxmx(keyed, len);
    }
}

XXH_FORCE_INLINE XXH_PUREF XXH64_hash_t
XXH3_len_9to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(input != NULL);
    XXH_ASSERT(secret != NULL);
    XXH_ASSERT(9 <= len && len <= 16);
    {   xxh_u64 const bitflip1 = (XXH_readLE64(secret+24) ^ XXH_readLE64(secret+32)) + seed;
        xxh_u64 const bitflip2 = (XXH_readLE64(secret+40) ^ XXH_readLE64(secret+48)) - seed;
        xxh_u64 const input_lo = XXH_readLE64(input)           ^ bitflip1;
        xxh_u64 const input_hi = XXH_readLE64(input + len - 8) ^ bitflip2;
        xxh_u64 const acc = len
                          + XXH_swap64(input_lo) + input_hi
                          + XXH3_mul128_fold64(input_lo, input_hi);
        return XXH3_avalanche(acc);
    }
}

XXH_FORCE_INLINE XXH_PUREF XXH64_hash_t
XXH3_len_0to16_64b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(len <= 16);
    {   if (XXH_likely(len >  8)) return XXH3_len_9to16_64b(input, len, secret, seed);
        if (XXH_likely(len >= 4)) return XXH3_len_4to8_64b(input, len, secret, seed);
        if (len) return XXH3_len_1to3_64b(input, len, secret, seed);
        return XXH64_avalanche(seed ^ (XXH_readLE64(secret+56) ^ XXH_readLE64(secret+64)));
    }
}

/*
 * DISCLAIMER: There are known *seed-dependent* multicollisions here due to
 * multiplication by zero, affecting hashes of lengths 17 to 240.
 *
 * However, they are very unlikely.
 *
 * Keep this in mind when using the unseeded XXH3_64bits() variant: As with all
 * unseeded non-cryptographic hashes, it does not attempt to defend itself
 * against specially crafted inputs, only random inputs.
 *
 * Compared to classic UMAC where a 1 in 2^31 chance of 4 consecutive bytes
 * cancelling out the secret is taken an arbitrary number of times (addressed
 * in XXH3_accumulate_512), this collision is very unlikely with random inputs
 * and/or proper seeding:
 *
 * This only has a 1 in 2^63 chance of 8 consecutive bytes cancelling out, in a
 * function that is only called up to 16 times per hash with up to 240 bytes of
 * input.
 *
 * This is not too bad for a non-cryptographic hash function, especially with
 * only 64 bit outputs.
 *
 * The 128-bit variant (which trades some speed for strength) is NOT affected
 * by this, although it is always a good idea to use a proper seed if you care
 * about strength.
 */
XXH_FORCE_INLINE xxh_u64 XXH3_mix16B(const xxh_u8* XXH_RESTRICT input,
                                     const xxh_u8* XXH_RESTRICT secret, xxh_u64 seed64)
{
#if defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
  && defined(__i386__) && defined(__SSE2__)  /* x86 + SSE2 */ \
  && !defined(XXH_ENABLE_AUTOVECTORIZE)      /* Define to disable like XXH32 hack */
    /*
     * UGLY HACK:
     * GCC for x86 tends to autovectorize the 128-bit multiply, resulting in
     * slower code.
     *
     * By forcing seed64 into a register, we disrupt the cost model and
     * cause it to scalarize. See `XXH32_round()`
     *
     * FIXME: Clang's output is still _much_ faster -- On an AMD Ryzen 3600,
     * XXH3_64bits @ len=240 runs at 4.6 GB/s with Clang 9, but 3.3 GB/s on
     * GCC 9.2, despite both emitting scalar code.
     *
     * GCC generates much better scalar code than Clang for the rest of XXH3,
     * which is why finding a more optimal codepath is an interest.
     */
    XXH_COMPILER_GUARD(seed64);
#endif
    {   xxh_u64 const input_lo = XXH_readLE64(input);
        xxh_u64 const input_hi = XXH_readLE64(input+8);
        return XXH3_mul128_fold64(
            input_lo ^ (XXH_readLE64(secret)   + seed64),
            input_hi ^ (XXH_readLE64(secret+8) - seed64)
        );
    }
}

/* For mid range keys, XXH3 uses a Mum-hash variant. */
XXH_FORCE_INLINE XXH_PUREF XXH64_hash_t
XXH3_len_17to128_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
                     const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
                     XXH64_hash_t seed)
{
    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
    XXH_ASSERT(16 < len && len <= 128);

    {   xxh_u64 acc = len * XXH_PRIME64_1;
#if XXH_SIZE_OPT >= 1
        /* Smaller and cleaner, but slightly slower. */
        unsigned int i = (unsigned int)(len - 1) / 32;
        do {
            acc += XXH3_mix16B(input+16 * i, secret+32*i, seed);
            acc += XXH3_mix16B(input+len-16*(i+1), secret+32*i+16, seed);
        } while (i-- != 0);
#else
        if (len > 32) {
            if (len > 64) {
                if (len > 96) {
                    acc += XXH3_mix16B(input+48, secret+96, seed);
                    acc += XXH3_mix16B(input+len-64, secret+112, seed);
                }
                acc += XXH3_mix16B(input+32, secret+64, seed);
                acc += XXH3_mix16B(input+len-48, secret+80, seed);
            }
            acc += XXH3_mix16B(input+16, secret+32, seed);
            acc += XXH3_mix16B(input+len-32, secret+48, seed);
        }
        acc += XXH3_mix16B(input+0, secret+0, seed);
        acc += XXH3_mix16B(input+len-16, secret+16, seed);
#endif
        return XXH3_avalanche(acc);
    }
}

/*!
 * @brief Maximum size of "short" key in bytes.
 */
#define XXH3_MIDSIZE_MAX 240

XXH_NO_INLINE XXH_PUREF XXH64_hash_t
XXH3_len_129to240_64b(const xxh_u8* XXH_RESTRICT input, size_t len,
                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
                      XXH64_hash_t seed)
{
    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
    XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);

    #define XXH3_MIDSIZE_STARTOFFSET 3
    #define XXH3_MIDSIZE_LASTOFFSET  17

    {   xxh_u64 acc = len * XXH_PRIME64_1;
        xxh_u64 acc_end;
        unsigned int const nbRounds = (unsigned int)len / 16;
        unsigned int i;
        XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);
        for (i=0; i<8; i++) {
            acc += XXH3_mix16B(input+(16*i), secret+(16*i), seed);
        }
        /* last bytes */
        acc_end = XXH3_mix16B(input + len - 16, secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET, seed);
        XXH_ASSERT(nbRounds >= 8);
        acc = XXH3_avalanche(acc);
#if defined(__clang__)                                /* Clang */ \
    && (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */ \
    && !defined(XXH_ENABLE_AUTOVECTORIZE)             /* Define to disable */
        /*
         * UGLY HACK:
         * Clang for ARMv7-A tries to vectorize this loop, similar to GCC x86.
         * In everywhere else, it uses scalar code.
         *
         * For 64->128-bit multiplies, even if the NEON was 100% optimal, it
         * would still be slower than UMAAL (see XXH_mult64to128).
         *
         * Unfortunately, Clang doesn't handle the long multiplies properly and
         * converts them to the nonexistent "vmulq_u64" intrinsic, which is then
         * scalarized into an ugly mess of VMOV.32 instructions.
         *
         * This mess is difficult to avoid without turning autovectorization
         * off completely, but they are usually relatively minor and/or not
         * worth it to fix.
         *
         * This loop is the easiest to fix, as unlike XXH32, this pragma
         * _actually works_ because it is a loop vectorization instead of an
         * SLP vectorization.
         */
        #pragma clang loop vectorize(disable)
#endif
        for (i=8 ; i < nbRounds; i++) {
            /*
             * Prevents clang for unrolling the acc loop and interleaving with this one.
             */
            XXH_COMPILER_GUARD(acc);
            acc_end += XXH3_mix16B(input+(16*i), secret+(16*(i-8)) + XXH3_MIDSIZE_STARTOFFSET, seed);
        }
        return XXH3_avalanche(acc + acc_end);
    }
}


/* =======     Long Keys     ======= */

#define XXH_STRIPE_LEN 64
#define XXH_SECRET_CONSUME_RATE 8   /* nb of secret bytes consumed at each accumulation */
#define XXH_ACC_NB (XXH_STRIPE_LEN / sizeof(xxh_u64))

#ifdef XXH_OLD_NAMES
#  define STRIPE_LEN XXH_STRIPE_LEN
#  define ACC_NB XXH_ACC_NB
#endif

#ifndef XXH_PREFETCH_DIST
#  ifdef __clang__
#    define XXH_PREFETCH_DIST 320
#  else
#    if (XXH_VECTOR == XXH_AVX512)
#      define XXH_PREFETCH_DIST 512
#    else
#      define XXH_PREFETCH_DIST 384
#    endif
#  endif  /* __clang__ */
#endif  /* XXH_PREFETCH_DIST */

/*
 * These macros are to generate an XXH3_accumulate() function.
 * The two arguments select the name suffix and target attribute.
 *
 * The name of this symbol is XXH3_accumulate_<name>() and it calls
 * XXH3_accumulate_512_<name>().
 *
 * It may be useful to hand implement this function if the compiler fails to
 * optimize the inline function.
 */
#define XXH3_ACCUMULATE_TEMPLATE(name)                      \
void                                                        \
XXH3_accumulate_##name(xxh_u64* XXH_RESTRICT acc,           \
                       const xxh_u8* XXH_RESTRICT input,    \
                       const xxh_u8* XXH_RESTRICT secret,   \
                       size_t nbStripes)                    \
{                                                           \
    size_t n;                                               \
    for (n = 0; n < nbStripes; n++ ) {                      \
        const xxh_u8* const in = input + n*XXH_STRIPE_LEN;  \
        XXH_PREFETCH(in + XXH_PREFETCH_DIST);               \
        XXH3_accumulate_512_##name(                         \
                 acc,                                       \
                 in,                                        \
                 secret + n*XXH_SECRET_CONSUME_RATE);       \
    }                                                       \
}


XXH_FORCE_INLINE void XXH_writeLE64(void* dst, xxh_u64 v64)
{
    if (!XXH_CPU_LITTLE_ENDIAN) v64 = XXH_swap64(v64);
    XXH_memcpy(dst, &v64, sizeof(v64));
}

/* Several intrinsic functions below are supposed to accept __int64 as argument,
 * as documented in https://software.intel.com/sites/landingpage/IntrinsicsGuide/ .
 * However, several environments do not define __int64 type,
 * requiring a workaround.
 */
#if !defined (__VMS) \
  && (defined (__cplusplus) \
  || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
    typedef int64_t xxh_i64;
#else
    /* the following type must have a width of 64-bit */
    typedef long long xxh_i64;
#endif


/*
 * XXH3_accumulate_512 is the tightest loop for long inputs, and it is the most optimized.
 *
 * It is a hardened version of UMAC, based off of FARSH's implementation.
 *
 * This was chosen because it adapts quite well to 32-bit, 64-bit, and SIMD
 * implementations, and it is ridiculously fast.
 *
 * We harden it by mixing the original input to the accumulators as well as the product.
 *
 * This means that in the (relatively likely) case of a multiply by zero, the
 * original input is preserved.
 *
 * On 128-bit inputs, we swap 64-bit pairs when we add the input to improve
 * cross-pollination, as otherwise the upper and lower halves would be
 * essentially independent.
 *
 * This doesn't matter on 64-bit hashes since they all get merged together in
 * the end, so we skip the extra step.
 *
 * Both XXH3_64bits and XXH3_128bits use this subroutine.
 */

#if (XXH_VECTOR == XXH_AVX512) \
     || (defined(XXH_DISPATCH_AVX512) && XXH_DISPATCH_AVX512 != 0)

#ifndef XXH_TARGET_AVX512
# define XXH_TARGET_AVX512  /* disable attribute target */
#endif

XXH_FORCE_INLINE XXH_TARGET_AVX512 void
XXH3_accumulate_512_avx512(void* XXH_RESTRICT acc,
                     const void* XXH_RESTRICT input,
                     const void* XXH_RESTRICT secret)
{
    __m512i* const xacc = (__m512i *) acc;
    XXH_ASSERT((((size_t)acc) & 63) == 0);
    XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));

    {
        /* data_vec    = input[0]; */
        __m512i const data_vec    = _mm512_loadu_si512   (input);
        /* key_vec     = secret[0]; */
        __m512i const key_vec     = _mm512_loadu_si512   (secret);
        /* data_key    = data_vec ^ key_vec; */
        __m512i const data_key    = _mm512_xor_si512     (data_vec, key_vec);
        /* data_key_lo = data_key >> 32; */
        __m512i const data_key_lo = _mm512_srli_epi64 (data_key, 32);
        /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
        __m512i const product     = _mm512_mul_epu32     (data_key, data_key_lo);
        /* xacc[0] += swap(data_vec); */
        __m512i const data_swap = _mm512_shuffle_epi32(data_vec, (_MM_PERM_ENUM)_MM_SHUFFLE(1, 0, 3, 2));
        __m512i const sum       = _mm512_add_epi64(*xacc, data_swap);
        /* xacc[0] += product; */
        *xacc = _mm512_add_epi64(product, sum);
    }
}
XXH_FORCE_INLINE XXH_TARGET_AVX512 XXH3_ACCUMULATE_TEMPLATE(avx512)

/*
 * XXH3_scrambleAcc: Scrambles the accumulators to improve mixing.
 *
 * Multiplication isn't perfect, as explained by Google in HighwayHash:
 *
 *  // Multiplication mixes/scrambles bytes 0-7 of the 64-bit result to
 *  // varying degrees. In descending order of goodness, bytes
 *  // 3 4 2 5 1 6 0 7 have quality 228 224 164 160 100 96 36 32.
 *  // As expected, the upper and lower bytes are much worse.
 *
 * Source: https://github.com/google/highwayhash/blob/0aaf66b/highwayhash/hh_avx2.h#L291
 *
 * Since our algorithm uses a pseudorandom secret to add some variance into the
 * mix, we don't need to (or want to) mix as often or as much as HighwayHash does.
 *
 * This isn't as tight as XXH3_accumulate, but still written in SIMD to avoid
 * extraction.
 *
 * Both XXH3_64bits and XXH3_128bits use this subroutine.
 */

XXH_FORCE_INLINE XXH_TARGET_AVX512 void
XXH3_scrambleAcc_avx512(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 63) == 0);
    XXH_STATIC_ASSERT(XXH_STRIPE_LEN == sizeof(__m512i));
    {   __m512i* const xacc = (__m512i*) acc;
        const __m512i prime32 = _mm512_set1_epi32((int)XXH_PRIME32_1);

        /* xacc[0] ^= (xacc[0] >> 47) */
        __m512i const acc_vec     = *xacc;
        __m512i const shifted     = _mm512_srli_epi64    (acc_vec, 47);
        /* xacc[0] ^= secret; */
        __m512i const key_vec     = _mm512_loadu_si512   (secret);
        __m512i const data_key    = _mm512_ternarylogic_epi32(key_vec, acc_vec, shifted, 0x96 /* key_vec ^ acc_vec ^ shifted */);

        /* xacc[0] *= XXH_PRIME32_1; */
        __m512i const data_key_hi = _mm512_srli_epi64 (data_key, 32);
        __m512i const prod_lo     = _mm512_mul_epu32     (data_key, prime32);
        __m512i const prod_hi     = _mm512_mul_epu32     (data_key_hi, prime32);
        *xacc = _mm512_add_epi64(prod_lo, _mm512_slli_epi64(prod_hi, 32));
    }
}

XXH_FORCE_INLINE XXH_TARGET_AVX512 void
XXH3_initCustomSecret_avx512(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
{
    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 63) == 0);
    XXH_STATIC_ASSERT(XXH_SEC_ALIGN == 64);
    XXH_ASSERT(((size_t)customSecret & 63) == 0);
    (void)(&XXH_writeLE64);
    {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m512i);
        __m512i const seed_pos = _mm512_set1_epi64((xxh_i64)seed64);
        __m512i const seed     = _mm512_mask_sub_epi64(seed_pos, 0xAA, _mm512_set1_epi8(0), seed_pos);

        const __m512i* const src  = (const __m512i*) ((const void*) XXH3_kSecret);
              __m512i* const dest = (      __m512i*) customSecret;
        int i;
        XXH_ASSERT(((size_t)src & 63) == 0); /* control alignment */
        XXH_ASSERT(((size_t)dest & 63) == 0);
        for (i=0; i < nbRounds; ++i) {
            dest[i] = _mm512_add_epi64(_mm512_load_si512(src + i), seed);
    }   }
}

#endif

#if (XXH_VECTOR == XXH_AVX2) \
    || (defined(XXH_DISPATCH_AVX2) && XXH_DISPATCH_AVX2 != 0)

#ifndef XXH_TARGET_AVX2
# define XXH_TARGET_AVX2  /* disable attribute target */
#endif

XXH_FORCE_INLINE XXH_TARGET_AVX2 void
XXH3_accumulate_512_avx2( void* XXH_RESTRICT acc,
                    const void* XXH_RESTRICT input,
                    const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 31) == 0);
    {   __m256i* const xacc    =       (__m256i *) acc;
        /* Unaligned. This is mainly for pointer arithmetic, and because
         * _mm256_loadu_si256 requires  a const __m256i * pointer for some reason. */
        const         __m256i* const xinput  = (const __m256i *) input;
        /* Unaligned. This is mainly for pointer arithmetic, and because
         * _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
        const         __m256i* const xsecret = (const __m256i *) secret;

        size_t i;
        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
            /* data_vec    = xinput[i]; */
            __m256i const data_vec    = _mm256_loadu_si256    (xinput+i);
            /* key_vec     = xsecret[i]; */
            __m256i const key_vec     = _mm256_loadu_si256   (xsecret+i);
            /* data_key    = data_vec ^ key_vec; */
            __m256i const data_key    = _mm256_xor_si256     (data_vec, key_vec);
            /* data_key_lo = data_key >> 32; */
            __m256i const data_key_lo = _mm256_srli_epi64 (data_key, 32);
            /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
            __m256i const product     = _mm256_mul_epu32     (data_key, data_key_lo);
            /* xacc[i] += swap(data_vec); */
            __m256i const data_swap = _mm256_shuffle_epi32(data_vec, _MM_SHUFFLE(1, 0, 3, 2));
            __m256i const sum       = _mm256_add_epi64(xacc[i], data_swap);
            /* xacc[i] += product; */
            xacc[i] = _mm256_add_epi64(product, sum);
    }   }
}
XXH_FORCE_INLINE XXH_TARGET_AVX2 XXH3_ACCUMULATE_TEMPLATE(avx2)

XXH_FORCE_INLINE XXH_TARGET_AVX2 void
XXH3_scrambleAcc_avx2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 31) == 0);
    {   __m256i* const xacc = (__m256i*) acc;
        /* Unaligned. This is mainly for pointer arithmetic, and because
         * _mm256_loadu_si256 requires a const __m256i * pointer for some reason. */
        const         __m256i* const xsecret = (const __m256i *) secret;
        const __m256i prime32 = _mm256_set1_epi32((int)XXH_PRIME32_1);

        size_t i;
        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m256i); i++) {
            /* xacc[i] ^= (xacc[i] >> 47) */
            __m256i const acc_vec     = xacc[i];
            __m256i const shifted     = _mm256_srli_epi64    (acc_vec, 47);
            __m256i const data_vec    = _mm256_xor_si256     (acc_vec, shifted);
            /* xacc[i] ^= xsecret; */
            __m256i const key_vec     = _mm256_loadu_si256   (xsecret+i);
            __m256i const data_key    = _mm256_xor_si256     (data_vec, key_vec);

            /* xacc[i] *= XXH_PRIME32_1; */
            __m256i const data_key_hi = _mm256_srli_epi64 (data_key, 32);
            __m256i const prod_lo     = _mm256_mul_epu32     (data_key, prime32);
            __m256i const prod_hi     = _mm256_mul_epu32     (data_key_hi, prime32);
            xacc[i] = _mm256_add_epi64(prod_lo, _mm256_slli_epi64(prod_hi, 32));
        }
    }
}

XXH_FORCE_INLINE XXH_TARGET_AVX2 void XXH3_initCustomSecret_avx2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
{
    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 31) == 0);
    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE / sizeof(__m256i)) == 6);
    XXH_STATIC_ASSERT(XXH_SEC_ALIGN <= 64);
    (void)(&XXH_writeLE64);
    XXH_PREFETCH(customSecret);
    {   __m256i const seed = _mm256_set_epi64x((xxh_i64)(0U - seed64), (xxh_i64)seed64, (xxh_i64)(0U - seed64), (xxh_i64)seed64);

        const __m256i* const src  = (const __m256i*) ((const void*) XXH3_kSecret);
              __m256i*       dest = (      __m256i*) customSecret;

#       if defined(__GNUC__) || defined(__clang__)
        /*
         * On GCC & Clang, marking 'dest' as modified will cause the compiler:
         *   - do not extract the secret from sse registers in the internal loop
         *   - use less common registers, and avoid pushing these reg into stack
         */
        XXH_COMPILER_GUARD(dest);
#       endif
        XXH_ASSERT(((size_t)src & 31) == 0); /* control alignment */
        XXH_ASSERT(((size_t)dest & 31) == 0);

        /* GCC -O2 need unroll loop manually */
        dest[0] = _mm256_add_epi64(_mm256_load_si256(src+0), seed);
        dest[1] = _mm256_add_epi64(_mm256_load_si256(src+1), seed);
        dest[2] = _mm256_add_epi64(_mm256_load_si256(src+2), seed);
        dest[3] = _mm256_add_epi64(_mm256_load_si256(src+3), seed);
        dest[4] = _mm256_add_epi64(_mm256_load_si256(src+4), seed);
        dest[5] = _mm256_add_epi64(_mm256_load_si256(src+5), seed);
    }
}

#endif

/* x86dispatch always generates SSE2 */
#if (XXH_VECTOR == XXH_SSE2) || defined(XXH_X86DISPATCH)

#ifndef XXH_TARGET_SSE2
# define XXH_TARGET_SSE2  /* disable attribute target */
#endif

XXH_FORCE_INLINE XXH_TARGET_SSE2 void
XXH3_accumulate_512_sse2( void* XXH_RESTRICT acc,
                    const void* XXH_RESTRICT input,
                    const void* XXH_RESTRICT secret)
{
    /* SSE2 is just a half-scale version of the AVX2 version. */
    XXH_ASSERT((((size_t)acc) & 15) == 0);
    {   __m128i* const xacc    =       (__m128i *) acc;
        /* Unaligned. This is mainly for pointer arithmetic, and because
         * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
        const         __m128i* const xinput  = (const __m128i *) input;
        /* Unaligned. This is mainly for pointer arithmetic, and because
         * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
        const         __m128i* const xsecret = (const __m128i *) secret;

        size_t i;
        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
            /* data_vec    = xinput[i]; */
            __m128i const data_vec    = _mm_loadu_si128   (xinput+i);
            /* key_vec     = xsecret[i]; */
            __m128i const key_vec     = _mm_loadu_si128   (xsecret+i);
            /* data_key    = data_vec ^ key_vec; */
            __m128i const data_key    = _mm_xor_si128     (data_vec, key_vec);
            /* data_key_lo = data_key >> 32; */
            __m128i const data_key_lo = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
            /* product     = (data_key & 0xffffffff) * (data_key_lo & 0xffffffff); */
            __m128i const product     = _mm_mul_epu32     (data_key, data_key_lo);
            /* xacc[i] += swap(data_vec); */
            __m128i const data_swap = _mm_shuffle_epi32(data_vec, _MM_SHUFFLE(1,0,3,2));
            __m128i const sum       = _mm_add_epi64(xacc[i], data_swap);
            /* xacc[i] += product; */
            xacc[i] = _mm_add_epi64(product, sum);
    }   }
}
XXH_FORCE_INLINE XXH_TARGET_SSE2 XXH3_ACCUMULATE_TEMPLATE(sse2)

XXH_FORCE_INLINE XXH_TARGET_SSE2 void
XXH3_scrambleAcc_sse2(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 15) == 0);
    {   __m128i* const xacc = (__m128i*) acc;
        /* Unaligned. This is mainly for pointer arithmetic, and because
         * _mm_loadu_si128 requires a const __m128i * pointer for some reason. */
        const         __m128i* const xsecret = (const __m128i *) secret;
        const __m128i prime32 = _mm_set1_epi32((int)XXH_PRIME32_1);

        size_t i;
        for (i=0; i < XXH_STRIPE_LEN/sizeof(__m128i); i++) {
            /* xacc[i] ^= (xacc[i] >> 47) */
            __m128i const acc_vec     = xacc[i];
            __m128i const shifted     = _mm_srli_epi64    (acc_vec, 47);
            __m128i const data_vec    = _mm_xor_si128     (acc_vec, shifted);
            /* xacc[i] ^= xsecret[i]; */
            __m128i const key_vec     = _mm_loadu_si128   (xsecret+i);
            __m128i const data_key    = _mm_xor_si128     (data_vec, key_vec);

            /* xacc[i] *= XXH_PRIME32_1; */
            __m128i const data_key_hi = _mm_shuffle_epi32 (data_key, _MM_SHUFFLE(0, 3, 0, 1));
            __m128i const prod_lo     = _mm_mul_epu32     (data_key, prime32);
            __m128i const prod_hi     = _mm_mul_epu32     (data_key_hi, prime32);
            xacc[i] = _mm_add_epi64(prod_lo, _mm_slli_epi64(prod_hi, 32));
        }
    }
}

XXH_FORCE_INLINE XXH_TARGET_SSE2 void XXH3_initCustomSecret_sse2(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
{
    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);
    (void)(&XXH_writeLE64);
    {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / sizeof(__m128i);

#       if defined(_MSC_VER) && defined(_M_IX86) && _MSC_VER < 1900
        /* MSVC 32bit mode does not support _mm_set_epi64x before 2015 */
        XXH_ALIGN(16) const xxh_i64 seed64x2[2] = { (xxh_i64)seed64, (xxh_i64)(0U - seed64) };
        __m128i const seed = _mm_load_si128((__m128i const*)seed64x2);
#       else
        __m128i const seed = _mm_set_epi64x((xxh_i64)(0U - seed64), (xxh_i64)seed64);
#       endif
        int i;

        const void* const src16 = XXH3_kSecret;
        __m128i* dst16 = (__m128i*) customSecret;
#       if defined(__GNUC__) || defined(__clang__)
        /*
         * On GCC & Clang, marking 'dest' as modified will cause the compiler:
         *   - do not extract the secret from sse registers in the internal loop
         *   - use less common registers, and avoid pushing these reg into stack
         */
        XXH_COMPILER_GUARD(dst16);
#       endif
        XXH_ASSERT(((size_t)src16 & 15) == 0); /* control alignment */
        XXH_ASSERT(((size_t)dst16 & 15) == 0);

        for (i=0; i < nbRounds; ++i) {
            dst16[i] = _mm_add_epi64(_mm_load_si128((const __m128i *)src16+i), seed);
    }   }
}

#endif

#if (XXH_VECTOR == XXH_NEON)

/* forward declarations for the scalar routines */
XXH_FORCE_INLINE void
XXH3_scalarRound(void* XXH_RESTRICT acc, void const* XXH_RESTRICT input,
                 void const* XXH_RESTRICT secret, size_t lane);

XXH_FORCE_INLINE void
XXH3_scalarScrambleRound(void* XXH_RESTRICT acc,
                         void const* XXH_RESTRICT secret, size_t lane);

/*!
 * @internal
 * @brief The bulk processing loop for NEON and WASM SIMD128.
 *
 * The NEON code path is actually partially scalar when running on AArch64. This
 * is to optimize the pipelining and can have up to 15% speedup depending on the
 * CPU, and it also mitigates some GCC codegen issues.
 *
 * @see XXH3_NEON_LANES for configuring this and details about this optimization.
 *
 * NEON's 32-bit to 64-bit long multiply takes a half vector of 32-bit
 * integers instead of the other platforms which mask full 64-bit vectors,
 * so the setup is more complicated than just shifting right.
 *
 * Additionally, there is an optimization for 4 lanes at once noted below.
 *
 * Since, as stated, the most optimal amount of lanes for Cortexes is 6,
 * there needs to be *three* versions of the accumulate operation used
 * for the remaining 2 lanes.
 *
 * WASM's SIMD128 uses SIMDe's arm_neon.h polyfill because the intrinsics overlap
 * nearly perfectly.
 */

XXH_FORCE_INLINE void
XXH3_accumulate_512_neon( void* XXH_RESTRICT acc,
                    const void* XXH_RESTRICT input,
                    const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 15) == 0);
    XXH_STATIC_ASSERT(XXH3_NEON_LANES > 0 && XXH3_NEON_LANES <= XXH_ACC_NB && XXH3_NEON_LANES % 2 == 0);
    {   /* GCC for darwin arm64 does not like aliasing here */
        xxh_aliasing_uint64x2_t* const xacc = (xxh_aliasing_uint64x2_t*) acc;
        /* We don't use a uint32x4_t pointer because it causes bus errors on ARMv7. */
        uint8_t const* xinput = (const uint8_t *) input;
        uint8_t const* xsecret  = (const uint8_t *) secret;

        size_t i;
#ifdef __wasm_simd128__
        /*
         * On WASM SIMD128, Clang emits direct address loads when XXH3_kSecret
         * is constant propagated, which results in it converting it to this
         * inside the loop:
         *
         *    a = v128.load(XXH3_kSecret +  0 + $secret_offset, offset = 0)
         *    b = v128.load(XXH3_kSecret + 16 + $secret_offset, offset = 0)
         *    ...
         *
         * This requires a full 32-bit address immediate (and therefore a 6 byte
         * instruction) as well as an add for each offset.
         *
         * Putting an asm guard prevents it from folding (at the cost of losing
         * the alignment hint), and uses the free offset in `v128.load` instead
         * of adding secret_offset each time which overall reduces code size by
         * about a kilobyte and improves performance.
         */
        XXH_COMPILER_GUARD(xsecret);
#endif
        /* Scalar lanes use the normal scalarRound routine */
        for (i = XXH3_NEON_LANES; i < XXH_ACC_NB; i++) {
            XXH3_scalarRound(acc, input, secret, i);
        }
        i = 0;
        /* 4 NEON lanes at a time. */
        for (; i+1 < XXH3_NEON_LANES / 2; i+=2) {
            /* data_vec = xinput[i]; */
            uint64x2_t data_vec_1 = XXH_vld1q_u64(xinput  + (i * 16));
            uint64x2_t data_vec_2 = XXH_vld1q_u64(xinput  + ((i+1) * 16));
            /* key_vec  = xsecret[i];  */
            uint64x2_t key_vec_1  = XXH_vld1q_u64(xsecret + (i * 16));
            uint64x2_t key_vec_2  = XXH_vld1q_u64(xsecret + ((i+1) * 16));
            /* data_swap = swap(data_vec) */
            uint64x2_t data_swap_1 = vextq_u64(data_vec_1, data_vec_1, 1);
            uint64x2_t data_swap_2 = vextq_u64(data_vec_2, data_vec_2, 1);
            /* data_key = data_vec ^ key_vec; */
            uint64x2_t data_key_1 = veorq_u64(data_vec_1, key_vec_1);
            uint64x2_t data_key_2 = veorq_u64(data_vec_2, key_vec_2);

            /*
             * If we reinterpret the 64x2 vectors as 32x4 vectors, we can use a
             * de-interleave operation for 4 lanes in 1 step with `vuzpq_u32` to
             * get one vector with the low 32 bits of each lane, and one vector
             * with the high 32 bits of each lane.
             *
             * The intrinsic returns a double vector because the original ARMv7-a
             * instruction modified both arguments in place. AArch64 and SIMD128 emit
             * two instructions from this intrinsic.
             *
             *  [ dk11L | dk11H | dk12L | dk12H ] -> [ dk11L | dk12L | dk21L | dk22L ]
             *  [ dk21L | dk21H | dk22L | dk22H ] -> [ dk11H | dk12H | dk21H | dk22H ]
             */
            uint32x4x2_t unzipped = vuzpq_u32(
                vreinterpretq_u32_u64(data_key_1),
                vreinterpretq_u32_u64(data_key_2)
            );
            /* data_key_lo = data_key & 0xFFFFFFFF */
            uint32x4_t data_key_lo = unzipped.val[0];
            /* data_key_hi = data_key >> 32 */
            uint32x4_t data_key_hi = unzipped.val[1];
            /*
             * Then, we can split the vectors horizontally and multiply which, as for most
             * widening intrinsics, have a variant that works on both high half vectors
             * for free on AArch64. A similar instruction is available on SIMD128.
             *
             * sum = data_swap + (u64x2) data_key_lo * (u64x2) data_key_hi
             */
            uint64x2_t sum_1 = XXH_vmlal_low_u32(data_swap_1, data_key_lo, data_key_hi);
            uint64x2_t sum_2 = XXH_vmlal_high_u32(data_swap_2, data_key_lo, data_key_hi);
            /*
             * Clang reorders
             *    a += b * c;     // umlal   swap.2d, dkl.2s, dkh.2s
             *    c += a;         // add     acc.2d, acc.2d, swap.2d
             * to
             *    c += a;         // add     acc.2d, acc.2d, swap.2d
             *    c += b * c;     // umlal   acc.2d, dkl.2s, dkh.2s
             *
             * While it would make sense in theory since the addition is faster,
             * for reasons likely related to umlal being limited to certain NEON
             * pipelines, this is worse. A compiler guard fixes this.
             */
            XXH_COMPILER_GUARD_CLANG_NEON(sum_1);
            XXH_COMPILER_GUARD_CLANG_NEON(sum_2);
            /* xacc[i] = acc_vec + sum; */
            xacc[i]   = vaddq_u64(xacc[i], sum_1);
            xacc[i+1] = vaddq_u64(xacc[i+1], sum_2);
        }
        /* Operate on the remaining NEON lanes 2 at a time. */
        for (; i < XXH3_NEON_LANES / 2; i++) {
            /* data_vec = xinput[i]; */
            uint64x2_t data_vec = XXH_vld1q_u64(xinput  + (i * 16));
            /* key_vec  = xsecret[i];  */
            uint64x2_t key_vec  = XXH_vld1q_u64(xsecret + (i * 16));
            /* acc_vec_2 = swap(data_vec) */
            uint64x2_t data_swap = vextq_u64(data_vec, data_vec, 1);
            /* data_key = data_vec ^ key_vec; */
            uint64x2_t data_key = veorq_u64(data_vec, key_vec);
            /* For two lanes, just use VMOVN and VSHRN. */
            /* data_key_lo = data_key & 0xFFFFFFFF; */
            uint32x2_t data_key_lo = vmovn_u64(data_key);
            /* data_key_hi = data_key >> 32; */
            uint32x2_t data_key_hi = vshrn_n_u64(data_key, 32);
            /* sum = data_swap + (u64x2) data_key_lo * (u64x2) data_key_hi; */
            uint64x2_t sum = vmlal_u32(data_swap, data_key_lo, data_key_hi);
            /* Same Clang workaround as before */
            XXH_COMPILER_GUARD_CLANG_NEON(sum);
            /* xacc[i] = acc_vec + sum; */
            xacc[i] = vaddq_u64 (xacc[i], sum);
        }
    }
}
XXH_FORCE_INLINE XXH3_ACCUMULATE_TEMPLATE(neon)

XXH_FORCE_INLINE void
XXH3_scrambleAcc_neon(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 15) == 0);

    {   xxh_aliasing_uint64x2_t* xacc       = (xxh_aliasing_uint64x2_t*) acc;
        uint8_t const* xsecret = (uint8_t const*) secret;

        size_t i;
        /* WASM uses operator overloads and doesn't need these. */
#ifndef __wasm_simd128__
        /* { prime32_1, prime32_1 } */
        uint32x2_t const kPrimeLo = vdup_n_u32(XXH_PRIME32_1);
        /* { 0, prime32_1, 0, prime32_1 } */
        uint32x4_t const kPrimeHi = vreinterpretq_u32_u64(vdupq_n_u64((xxh_u64)XXH_PRIME32_1 << 32));
#endif

        /* AArch64 uses both scalar and neon at the same time */
        for (i = XXH3_NEON_LANES; i < XXH_ACC_NB; i++) {
            XXH3_scalarScrambleRound(acc, secret, i);
        }
        for (i=0; i < XXH3_NEON_LANES / 2; i++) {
            /* xacc[i] ^= (xacc[i] >> 47); */
            uint64x2_t acc_vec  = xacc[i];
            uint64x2_t shifted  = vshrq_n_u64(acc_vec, 47);
            uint64x2_t data_vec = veorq_u64(acc_vec, shifted);

            /* xacc[i] ^= xsecret[i]; */
            uint64x2_t key_vec  = XXH_vld1q_u64(xsecret + (i * 16));
            uint64x2_t data_key = veorq_u64(data_vec, key_vec);
            /* xacc[i] *= XXH_PRIME32_1 */
#ifdef __wasm_simd128__
            /* SIMD128 has multiply by u64x2, use it instead of expanding and scalarizing */
            xacc[i] = data_key * XXH_PRIME32_1;
#else
            /*
             * Expanded version with portable NEON intrinsics
             *
             *    lo(x) * lo(y) + (hi(x) * lo(y) << 32)
             *
             * prod_hi = hi(data_key) * lo(prime) << 32
             *
             * Since we only need 32 bits of this multiply a trick can be used, reinterpreting the vector
             * as a uint32x4_t and multiplying by { 0, prime, 0, prime } to cancel out the unwanted bits
             * and avoid the shift.
             */
            uint32x4_t prod_hi = vmulq_u32 (vreinterpretq_u32_u64(data_key), kPrimeHi);
            /* Extract low bits for vmlal_u32  */
            uint32x2_t data_key_lo = vmovn_u64(data_key);
            /* xacc[i] = prod_hi + lo(data_key) * XXH_PRIME32_1; */
            xacc[i] = vmlal_u32(vreinterpretq_u64_u32(prod_hi), data_key_lo, kPrimeLo);
#endif
        }
    }
}
#endif

#if (XXH_VECTOR == XXH_VSX)

XXH_FORCE_INLINE void
XXH3_accumulate_512_vsx(  void* XXH_RESTRICT acc,
                    const void* XXH_RESTRICT input,
                    const void* XXH_RESTRICT secret)
{
    /* presumed aligned */
    xxh_aliasing_u64x2* const xacc = (xxh_aliasing_u64x2*) acc;
    xxh_u8 const* const xinput   = (xxh_u8 const*) input;   /* no alignment restriction */
    xxh_u8 const* const xsecret  = (xxh_u8 const*) secret;    /* no alignment restriction */
    xxh_u64x2 const v32 = { 32, 32 };
    size_t i;
    for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
        /* data_vec = xinput[i]; */
        xxh_u64x2 const data_vec = XXH_vec_loadu(xinput + 16*i);
        /* key_vec = xsecret[i]; */
        xxh_u64x2 const key_vec  = XXH_vec_loadu(xsecret + 16*i);
        xxh_u64x2 const data_key = data_vec ^ key_vec;
        /* shuffled = (data_key << 32) | (data_key >> 32); */
        xxh_u32x4 const shuffled = (xxh_u32x4)vec_rl(data_key, v32);
        /* product = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)shuffled & 0xFFFFFFFF); */
        xxh_u64x2 const product  = XXH_vec_mulo((xxh_u32x4)data_key, shuffled);
        /* acc_vec = xacc[i]; */
        xxh_u64x2 acc_vec        = xacc[i];
        acc_vec += product;

        /* swap high and low halves */
#ifdef __s390x__
        acc_vec += vec_permi(data_vec, data_vec, 2);
#else
        acc_vec += vec_xxpermdi(data_vec, data_vec, 2);
#endif
        xacc[i] = acc_vec;
    }
}
XXH_FORCE_INLINE XXH3_ACCUMULATE_TEMPLATE(vsx)

XXH_FORCE_INLINE void
XXH3_scrambleAcc_vsx(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
    XXH_ASSERT((((size_t)acc) & 15) == 0);

    {   xxh_aliasing_u64x2* const xacc = (xxh_aliasing_u64x2*) acc;
        const xxh_u8* const xsecret = (const xxh_u8*) secret;
        /* constants */
        xxh_u64x2 const v32  = { 32, 32 };
        xxh_u64x2 const v47 = { 47, 47 };
        xxh_u32x4 const prime = { XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1, XXH_PRIME32_1 };
        size_t i;
        for (i = 0; i < XXH_STRIPE_LEN / sizeof(xxh_u64x2); i++) {
            /* xacc[i] ^= (xacc[i] >> 47); */
            xxh_u64x2 const acc_vec  = xacc[i];
            xxh_u64x2 const data_vec = acc_vec ^ (acc_vec >> v47);

            /* xacc[i] ^= xsecret[i]; */
            xxh_u64x2 const key_vec  = XXH_vec_loadu(xsecret + 16*i);
            xxh_u64x2 const data_key = data_vec ^ key_vec;

            /* xacc[i] *= XXH_PRIME32_1 */
            /* prod_lo = ((xxh_u64x2)data_key & 0xFFFFFFFF) * ((xxh_u64x2)prime & 0xFFFFFFFF);  */
            xxh_u64x2 const prod_even  = XXH_vec_mule((xxh_u32x4)data_key, prime);
            /* prod_hi = ((xxh_u64x2)data_key >> 32) * ((xxh_u64x2)prime >> 32);  */
            xxh_u64x2 const prod_odd  = XXH_vec_mulo((xxh_u32x4)data_key, prime);
            xacc[i] = prod_odd + (prod_even << v32);
    }   }
}

#endif

#if (XXH_VECTOR == XXH_SVE)

XXH_FORCE_INLINE void
XXH3_accumulate_512_sve( void* XXH_RESTRICT acc,
                   const void* XXH_RESTRICT input,
                   const void* XXH_RESTRICT secret)
{
    uint64_t *xacc = (uint64_t *)acc;
    const uint64_t *xinput = (const uint64_t *)(const void *)input;
    const uint64_t *xsecret = (const uint64_t *)(const void *)secret;
    svuint64_t kSwap = sveor_n_u64_z(svptrue_b64(), svindex_u64(0, 1), 1);
    uint64_t element_count = svcntd();
    if (element_count >= 8) {
        svbool_t mask = svptrue_pat_b64(SV_VL8);
        svuint64_t vacc = svld1_u64(mask, xacc);
        ACCRND(vacc, 0);
        svst1_u64(mask, xacc, vacc);
    } else if (element_count == 2) {   /* sve128 */
        svbool_t mask = svptrue_pat_b64(SV_VL2);
        svuint64_t acc0 = svld1_u64(mask, xacc + 0);
        svuint64_t acc1 = svld1_u64(mask, xacc + 2);
        svuint64_t acc2 = svld1_u64(mask, xacc + 4);
        svuint64_t acc3 = svld1_u64(mask, xacc + 6);
        ACCRND(acc0, 0);
        ACCRND(acc1, 2);
        ACCRND(acc2, 4);
        ACCRND(acc3, 6);
        svst1_u64(mask, xacc + 0, acc0);
        svst1_u64(mask, xacc + 2, acc1);
        svst1_u64(mask, xacc + 4, acc2);
        svst1_u64(mask, xacc + 6, acc3);
    } else {
        svbool_t mask = svptrue_pat_b64(SV_VL4);
        svuint64_t acc0 = svld1_u64(mask, xacc + 0);
        svuint64_t acc1 = svld1_u64(mask, xacc + 4);
        ACCRND(acc0, 0);
        ACCRND(acc1, 4);
        svst1_u64(mask, xacc + 0, acc0);
        svst1_u64(mask, xacc + 4, acc1);
    }
}

XXH_FORCE_INLINE void
XXH3_accumulate_sve(xxh_u64* XXH_RESTRICT acc,
               const xxh_u8* XXH_RESTRICT input,
               const xxh_u8* XXH_RESTRICT secret,
               size_t nbStripes)
{
    if (nbStripes != 0) {
        uint64_t *xacc = (uint64_t *)acc;
        const uint64_t *xinput = (const uint64_t *)(const void *)input;
        const uint64_t *xsecret = (const uint64_t *)(const void *)secret;
        svuint64_t kSwap = sveor_n_u64_z(svptrue_b64(), svindex_u64(0, 1), 1);
        uint64_t element_count = svcntd();
        if (element_count >= 8) {
            svbool_t mask = svptrue_pat_b64(SV_VL8);
            svuint64_t vacc = svld1_u64(mask, xacc + 0);
            do {
                /* svprfd(svbool_t, void *, enum svfprop); */
                svprfd(mask, xinput + 128, SV_PLDL1STRM);
                ACCRND(vacc, 0);
                xinput += 8;
                xsecret += 1;
                nbStripes--;
           } while (nbStripes != 0);

           svst1_u64(mask, xacc + 0, vacc);
        } else if (element_count == 2) { /* sve128 */
            svbool_t mask = svptrue_pat_b64(SV_VL2);
            svuint64_t acc0 = svld1_u64(mask, xacc + 0);
            svuint64_t acc1 = svld1_u64(mask, xacc + 2);
            svuint64_t acc2 = svld1_u64(mask, xacc + 4);
            svuint64_t acc3 = svld1_u64(mask, xacc + 6);
            do {
                svprfd(mask, xinput + 128, SV_PLDL1STRM);
                ACCRND(acc0, 0);
                ACCRND(acc1, 2);
                ACCRND(acc2, 4);
                ACCRND(acc3, 6);
                xinput += 8;
                xsecret += 1;
                nbStripes--;
           } while (nbStripes != 0);

           svst1_u64(mask, xacc + 0, acc0);
           svst1_u64(mask, xacc + 2, acc1);
           svst1_u64(mask, xacc + 4, acc2);
           svst1_u64(mask, xacc + 6, acc3);
        } else {
            svbool_t mask = svptrue_pat_b64(SV_VL4);
            svuint64_t acc0 = svld1_u64(mask, xacc + 0);
            svuint64_t acc1 = svld1_u64(mask, xacc + 4);
            do {
                svprfd(mask, xinput + 128, SV_PLDL1STRM);
                ACCRND(acc0, 0);
                ACCRND(acc1, 4);
                xinput += 8;
                xsecret += 1;
                nbStripes--;
           } while (nbStripes != 0);

           svst1_u64(mask, xacc + 0, acc0);
           svst1_u64(mask, xacc + 4, acc1);
       }
    }
}

#endif

/* scalar variants - universal */

#if defined(__aarch64__) && (defined(__GNUC__) || defined(__clang__))
/*
 * In XXH3_scalarRound(), GCC and Clang have a similar codegen issue, where they
 * emit an excess mask and a full 64-bit multiply-add (MADD X-form).
 *
 * While this might not seem like much, as AArch64 is a 64-bit architecture, only
 * big Cortex designs have a full 64-bit multiplier.
 *
 * On the little cores, the smaller 32-bit multiplier is used, and full 64-bit
 * multiplies expand to 2-3 multiplies in microcode. This has a major penalty
 * of up to 4 latency cycles and 2 stall cycles in the multiply pipeline.
 *
 * Thankfully, AArch64 still provides the 32-bit long multiply-add (UMADDL) which does
 * not have this penalty and does the mask automatically.
 */
XXH_FORCE_INLINE xxh_u64
XXH_mult32to64_add64(xxh_u64 lhs, xxh_u64 rhs, xxh_u64 acc)
{
    xxh_u64 ret;
    /* note: %x = 64-bit register, %w = 32-bit register */
    __asm__("umaddl %x0, %w1, %w2, %x3" : "=r" (ret) : "r" (lhs), "r" (rhs), "r" (acc));
    return ret;
}
#else
XXH_FORCE_INLINE xxh_u64
XXH_mult32to64_add64(xxh_u64 lhs, xxh_u64 rhs, xxh_u64 acc)
{
    return XXH_mult32to64((xxh_u32)lhs, (xxh_u32)rhs) + acc;
}
#endif

/*!
 * @internal
 * @brief Scalar round for @ref XXH3_accumulate_512_scalar().
 *
 * This is extracted to its own function because the NEON path uses a combination
 * of NEON and scalar.
 */
XXH_FORCE_INLINE void
XXH3_scalarRound(void* XXH_RESTRICT acc,
                 void const* XXH_RESTRICT input,
                 void const* XXH_RESTRICT secret,
                 size_t lane)
{
    xxh_u64* xacc = (xxh_u64*) acc;
    xxh_u8 const* xinput  = (xxh_u8 const*) input;
    xxh_u8 const* xsecret = (xxh_u8 const*) secret;
    XXH_ASSERT(lane < XXH_ACC_NB);
    XXH_ASSERT(((size_t)acc & (XXH_ACC_ALIGN-1)) == 0);
    {
        xxh_u64 const data_val = XXH_readLE64(xinput + lane * 8);
        xxh_u64 const data_key = data_val ^ XXH_readLE64(xsecret + lane * 8);
        xacc[lane ^ 1] += data_val; /* swap adjacent lanes */
        xacc[lane] = XXH_mult32to64_add64(data_key /* & 0xFFFFFFFF */, data_key >> 32, xacc[lane]);
    }
}

/*!
 * @internal
 * @brief Processes a 64 byte block of data using the scalar path.
 */
XXH_FORCE_INLINE void
XXH3_accumulate_512_scalar(void* XXH_RESTRICT acc,
                     const void* XXH_RESTRICT input,
                     const void* XXH_RESTRICT secret)
{
    size_t i;
    /* ARM GCC refuses to unroll this loop, resulting in a 24% slowdown on ARMv6. */
#if defined(__GNUC__) && !defined(__clang__) \
  && (defined(__arm__) || defined(__thumb2__)) \
  && defined(__ARM_FEATURE_UNALIGNED) /* no unaligned access just wastes bytes */ \
  && XXH_SIZE_OPT <= 0
#  pragma GCC unroll 8
#endif
    for (i=0; i < XXH_ACC_NB; i++) {
        XXH3_scalarRound(acc, input, secret, i);
    }
}
XXH_FORCE_INLINE XXH3_ACCUMULATE_TEMPLATE(scalar)

/*!
 * @internal
 * @brief Scalar scramble step for @ref XXH3_scrambleAcc_scalar().
 *
 * This is extracted to its own function because the NEON path uses a combination
 * of NEON and scalar.
 */
XXH_FORCE_INLINE void
XXH3_scalarScrambleRound(void* XXH_RESTRICT acc,
                         void const* XXH_RESTRICT secret,
                         size_t lane)
{
    xxh_u64* const xacc = (xxh_u64*) acc;   /* presumed aligned */
    const xxh_u8* const xsecret = (const xxh_u8*) secret;   /* no alignment restriction */
    XXH_ASSERT((((size_t)acc) & (XXH_ACC_ALIGN-1)) == 0);
    XXH_ASSERT(lane < XXH_ACC_NB);
    {
        xxh_u64 const key64 = XXH_readLE64(xsecret + lane * 8);
        xxh_u64 acc64 = xacc[lane];
        acc64 = XXH_xorshift64(acc64, 47);
        acc64 ^= key64;
        acc64 *= XXH_PRIME32_1;
        xacc[lane] = acc64;
    }
}

/*!
 * @internal
 * @brief Scrambles the accumulators after a large chunk has been read
 */
XXH_FORCE_INLINE void
XXH3_scrambleAcc_scalar(void* XXH_RESTRICT acc, const void* XXH_RESTRICT secret)
{
    size_t i;
    for (i=0; i < XXH_ACC_NB; i++) {
        XXH3_scalarScrambleRound(acc, secret, i);
    }
}

XXH_FORCE_INLINE void
XXH3_initCustomSecret_scalar(void* XXH_RESTRICT customSecret, xxh_u64 seed64)
{
    /*
     * We need a separate pointer for the hack below,
     * which requires a non-const pointer.
     * Any decent compiler will optimize this out otherwise.
     */
    const xxh_u8* kSecretPtr = XXH3_kSecret;
    XXH_STATIC_ASSERT((XXH_SECRET_DEFAULT_SIZE & 15) == 0);

#if defined(__GNUC__) && defined(__aarch64__)
    /*
     * UGLY HACK:
     * GCC and Clang generate a bunch of MOV/MOVK pairs for aarch64, and they are
     * placed sequentially, in order, at the top of the unrolled loop.
     *
     * While MOVK is great for generating constants (2 cycles for a 64-bit
     * constant compared to 4 cycles for LDR), it fights for bandwidth with
     * the arithmetic instructions.
     *
     *   I   L   S
     * MOVK
     * MOVK
     * MOVK
     * MOVK
     * ADD
     * SUB      STR
     *          STR
     * By forcing loads from memory (as the asm line causes the compiler to assume
     * that XXH3_kSecretPtr has been changed), the pipelines are used more
     * efficiently:
     *   I   L   S
     *      LDR
     *  ADD LDR
     *  SUB     STR
     *          STR
     *
     * See XXH3_NEON_LANES for details on the pipsline.
     *
     * XXH3_64bits_withSeed, len == 256, Snapdragon 835
     *   without hack: 2654.4 MB/s
     *   with hack:    3202.9 MB/s
     */
    XXH_COMPILER_GUARD(kSecretPtr);
#endif
    {   int const nbRounds = XXH_SECRET_DEFAULT_SIZE / 16;
        int i;
        for (i=0; i < nbRounds; i++) {
            /*
             * The asm hack causes the compiler to assume that kSecretPtr aliases with
             * customSecret, and on aarch64, this prevented LDP from merging two
             * loads together for free. Putting the loads together before the stores
             * properly generates LDP.
             */
            xxh_u64 lo = XXH_readLE64(kSecretPtr + 16*i)     + seed64;
            xxh_u64 hi = XXH_readLE64(kSecretPtr + 16*i + 8) - seed64;
            XXH_writeLE64((xxh_u8*)customSecret + 16*i,     lo);
            XXH_writeLE64((xxh_u8*)customSecret + 16*i + 8, hi);
    }   }
}


typedef void (*XXH3_f_accumulate)(xxh_u64* XXH_RESTRICT, const xxh_u8* XXH_RESTRICT, const xxh_u8* XXH_RESTRICT, size_t);
typedef void (*XXH3_f_scrambleAcc)(void* XXH_RESTRICT, const void*);
typedef void (*XXH3_f_initCustomSecret)(void* XXH_RESTRICT, xxh_u64);


#if (XXH_VECTOR == XXH_AVX512)

#define XXH3_accumulate_512 XXH3_accumulate_512_avx512
#define XXH3_accumulate     XXH3_accumulate_avx512
#define XXH3_scrambleAcc    XXH3_scrambleAcc_avx512
#define XXH3_initCustomSecret XXH3_initCustomSecret_avx512

#elif (XXH_VECTOR == XXH_AVX2)

#define XXH3_accumulate_512 XXH3_accumulate_512_avx2
#define XXH3_accumulate     XXH3_accumulate_avx2
#define XXH3_scrambleAcc    XXH3_scrambleAcc_avx2
#define XXH3_initCustomSecret XXH3_initCustomSecret_avx2

#elif (XXH_VECTOR == XXH_SSE2)

#define XXH3_accumulate_512 XXH3_accumulate_512_sse2
#define XXH3_accumulate     XXH3_accumulate_sse2
#define XXH3_scrambleAcc    XXH3_scrambleAcc_sse2
#define XXH3_initCustomSecret XXH3_initCustomSecret_sse2

#elif (XXH_VECTOR == XXH_NEON)

#define XXH3_accumulate_512 XXH3_accumulate_512_neon
#define XXH3_accumulate     XXH3_accumulate_neon
#define XXH3_scrambleAcc    XXH3_scrambleAcc_neon
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar

#elif (XXH_VECTOR == XXH_VSX)

#define XXH3_accumulate_512 XXH3_accumulate_512_vsx
#define XXH3_accumulate     XXH3_accumulate_vsx
#define XXH3_scrambleAcc    XXH3_scrambleAcc_vsx
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar

#elif (XXH_VECTOR == XXH_SVE)
#define XXH3_accumulate_512 XXH3_accumulate_512_sve
#define XXH3_accumulate     XXH3_accumulate_sve
#define XXH3_scrambleAcc    XXH3_scrambleAcc_scalar
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar

#else /* scalar */

#define XXH3_accumulate_512 XXH3_accumulate_512_scalar
#define XXH3_accumulate     XXH3_accumulate_scalar
#define XXH3_scrambleAcc    XXH3_scrambleAcc_scalar
#define XXH3_initCustomSecret XXH3_initCustomSecret_scalar

#endif

#if XXH_SIZE_OPT >= 1 /* don't do SIMD for initialization */
#  undef XXH3_initCustomSecret
#  define XXH3_initCustomSecret XXH3_initCustomSecret_scalar
#endif

XXH_FORCE_INLINE void
XXH3_hashLong_internal_loop(xxh_u64* XXH_RESTRICT acc,
                      const xxh_u8* XXH_RESTRICT input, size_t len,
                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
                            XXH3_f_accumulate f_acc,
                            XXH3_f_scrambleAcc f_scramble)
{
    size_t const nbStripesPerBlock = (secretSize - XXH_STRIPE_LEN) / XXH_SECRET_CONSUME_RATE;
    size_t const block_len = XXH_STRIPE_LEN * nbStripesPerBlock;
    size_t const nb_blocks = (len - 1) / block_len;

    size_t n;

    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);

    for (n = 0; n < nb_blocks; n++) {
        f_acc(acc, input + n*block_len, secret, nbStripesPerBlock);
        f_scramble(acc, secret + secretSize - XXH_STRIPE_LEN);
    }

    /* last partial block */
    XXH_ASSERT(len > XXH_STRIPE_LEN);
    {   size_t const nbStripes = ((len - 1) - (block_len * nb_blocks)) / XXH_STRIPE_LEN;
        XXH_ASSERT(nbStripes <= (secretSize / XXH_SECRET_CONSUME_RATE));
        f_acc(acc, input + nb_blocks*block_len, secret, nbStripes);

        /* last stripe */
        {   const xxh_u8* const p = input + len - XXH_STRIPE_LEN;
#define XXH_SECRET_LASTACC_START 7  /* not aligned on 8, last secret is different from acc & scrambler */
            XXH3_accumulate_512(acc, p, secret + secretSize - XXH_STRIPE_LEN - XXH_SECRET_LASTACC_START);
    }   }
}

XXH_FORCE_INLINE xxh_u64
XXH3_mix2Accs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret)
{
    return XXH3_mul128_fold64(
               acc[0] ^ XXH_readLE64(secret),
               acc[1] ^ XXH_readLE64(secret+8) );
}

static XXH64_hash_t
XXH3_mergeAccs(const xxh_u64* XXH_RESTRICT acc, const xxh_u8* XXH_RESTRICT secret, xxh_u64 start)
{
    xxh_u64 result64 = start;
    size_t i = 0;

    for (i = 0; i < 4; i++) {
        result64 += XXH3_mix2Accs(acc+2*i, secret + 16*i);
#if defined(__clang__)                                /* Clang */ \
    && (defined(__arm__) || defined(__thumb__))       /* ARMv7 */ \
    && (defined(__ARM_NEON) || defined(__ARM_NEON__)) /* NEON */  \
    && !defined(XXH_ENABLE_AUTOVECTORIZE)             /* Define to disable */
        /*
         * UGLY HACK:
         * Prevent autovectorization on Clang ARMv7-a. Exact same problem as
         * the one in XXH3_len_129to240_64b. Speeds up shorter keys > 240b.
         * XXH3_64bits, len == 256, Snapdragon 835:
         *   without hack: 2063.7 MB/s
         *   with hack:    2560.7 MB/s
         */
        XXH_COMPILER_GUARD(result64);
#endif
    }

    return XXH3_avalanche(result64);
}

#define XXH3_INIT_ACC { XXH_PRIME32_3, XXH_PRIME64_1, XXH_PRIME64_2, XXH_PRIME64_3, \
                        XXH_PRIME64_4, XXH_PRIME32_2, XXH_PRIME64_5, XXH_PRIME32_1 }

XXH_FORCE_INLINE XXH64_hash_t
XXH3_hashLong_64b_internal(const void* XXH_RESTRICT input, size_t len,
                           const void* XXH_RESTRICT secret, size_t secretSize,
                           XXH3_f_accumulate f_acc,
                           XXH3_f_scrambleAcc f_scramble)
{
    XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;

    XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, (const xxh_u8*)secret, secretSize, f_acc, f_scramble);

    /* converge into final hash */
    XXH_STATIC_ASSERT(sizeof(acc) == 64);
    /* do not align on 8, so that the secret is different from the accumulator */
#define XXH_SECRET_MERGEACCS_START 11
    XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
    return XXH3_mergeAccs(acc, (const xxh_u8*)secret + XXH_SECRET_MERGEACCS_START, (xxh_u64)len * XXH_PRIME64_1);
}

/*
 * It's important for performance to transmit secret's size (when it's static)
 * so that the compiler can properly optimize the vectorized loop.
 * This makes a big performance difference for "medium" keys (<1 KB) when using AVX instruction set.
 * When the secret size is unknown, or on GCC 12 where the mix of NO_INLINE and FORCE_INLINE
 * breaks -Og, this is XXH_NO_INLINE.
 */
XXH3_WITH_SECRET_INLINE XXH64_hash_t
XXH3_hashLong_64b_withSecret(const void* XXH_RESTRICT input, size_t len,
                             XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
{
    (void)seed64;
    return XXH3_hashLong_64b_internal(input, len, secret, secretLen, XXH3_accumulate, XXH3_scrambleAcc);
}

/*
 * It's preferable for performance that XXH3_hashLong is not inlined,
 * as it results in a smaller function for small data, easier to the instruction cache.
 * Note that inside this no_inline function, we do inline the internal loop,
 * and provide a statically defined secret size to allow optimization of vector loop.
 */
XXH_NO_INLINE XXH_PUREF XXH64_hash_t
XXH3_hashLong_64b_default(const void* XXH_RESTRICT input, size_t len,
                          XXH64_hash_t seed64, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
{
    (void)seed64; (void)secret; (void)secretLen;
    return XXH3_hashLong_64b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_accumulate, XXH3_scrambleAcc);
}

/*
 * XXH3_hashLong_64b_withSeed():
 * Generate a custom key based on alteration of default XXH3_kSecret with the seed,
 * and then use this key for long mode hashing.
 *
 * This operation is decently fast but nonetheless costs a little bit of time.
 * Try to avoid it whenever possible (typically when seed==0).
 *
 * It's important for performance that XXH3_hashLong is not inlined. Not sure
 * why (uop cache maybe?), but the difference is large and easily measurable.
 */
XXH_FORCE_INLINE XXH64_hash_t
XXH3_hashLong_64b_withSeed_internal(const void* input, size_t len,
                                    XXH64_hash_t seed,
                                    XXH3_f_accumulate f_acc,
                                    XXH3_f_scrambleAcc f_scramble,
                                    XXH3_f_initCustomSecret f_initSec)
{
#if XXH_SIZE_OPT <= 0
    if (seed == 0)
        return XXH3_hashLong_64b_internal(input, len,
                                          XXH3_kSecret, sizeof(XXH3_kSecret),
                                          f_acc, f_scramble);
#endif
    {   XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
        f_initSec(secret, seed);
        return XXH3_hashLong_64b_internal(input, len, secret, sizeof(secret),
                                          f_acc, f_scramble);
    }
}

/*
 * It's important for performance that XXH3_hashLong is not inlined.
 */
XXH_NO_INLINE XXH64_hash_t
XXH3_hashLong_64b_withSeed(const void* XXH_RESTRICT input, size_t len,
                           XXH64_hash_t seed, const xxh_u8* XXH_RESTRICT secret, size_t secretLen)
{
    (void)secret; (void)secretLen;
    return XXH3_hashLong_64b_withSeed_internal(input, len, seed,
                XXH3_accumulate, XXH3_scrambleAcc, XXH3_initCustomSecret);
}


typedef XXH64_hash_t (*XXH3_hashLong64_f)(const void* XXH_RESTRICT, size_t,
                                          XXH64_hash_t, const xxh_u8* XXH_RESTRICT, size_t);

XXH_FORCE_INLINE XXH64_hash_t
XXH3_64bits_internal(const void* XXH_RESTRICT input, size_t len,
                     XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
                     XXH3_hashLong64_f f_hashLong)
{
    XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
    /*
     * If an action is to be taken if `secretLen` condition is not respected,
     * it should be done here.
     * For now, it's a contract pre-condition.
     * Adding a check and a branch here would cost performance at every hash.
     * Also, note that function signature doesn't offer room to return an error.
     */
    if (len <= 16)
        return XXH3_len_0to16_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
    if (len <= 128)
        return XXH3_len_17to128_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
    if (len <= XXH3_MIDSIZE_MAX)
        return XXH3_len_129to240_64b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
    return f_hashLong(input, len, seed64, (const xxh_u8*)secret, secretLen);
}


/* ===   Public entry point   === */

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits(XXH_NOESCAPE const void* input, size_t length)
{
    return XXH3_64bits_internal(input, length, 0, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_default);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH64_hash_t
XXH3_64bits_withSecret(XXH_NOESCAPE const void* input, size_t length, XXH_NOESCAPE const void* secret, size_t secretSize)
{
    return XXH3_64bits_internal(input, length, 0, secret, secretSize, XXH3_hashLong_64b_withSecret);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH64_hash_t
XXH3_64bits_withSeed(XXH_NOESCAPE const void* input, size_t length, XXH64_hash_t seed)
{
    return XXH3_64bits_internal(input, length, seed, XXH3_kSecret, sizeof(XXH3_kSecret), XXH3_hashLong_64b_withSeed);
}

XXH_PUBLIC_API XXH64_hash_t
XXH3_64bits_withSecretandSeed(XXH_NOESCAPE const void* input, size_t length, XXH_NOESCAPE const void* secret, size_t secretSize, XXH64_hash_t seed)
{
    if (length <= XXH3_MIDSIZE_MAX)
        return XXH3_64bits_internal(input, length, seed, XXH3_kSecret, sizeof(XXH3_kSecret), NULL);
    return XXH3_hashLong_64b_withSecret(input, length, seed, (const xxh_u8*)secret, secretSize);
}


/* ===   XXH3 streaming   === */
#ifndef XXH_NO_STREAM
/*
 * Malloc's a pointer that is always aligned to align.
 *
 * This must be freed with `XXH_alignedFree()`.
 *
 * malloc typically guarantees 16 byte alignment on 64-bit systems and 8 byte
 * alignment on 32-bit. This isn't enough for the 32 byte aligned loads in AVX2
 * or on 32-bit, the 16 byte aligned loads in SSE2 and NEON.
 *
 * This underalignment previously caused a rather obvious crash which went
 * completely unnoticed due to XXH3_createState() not actually being tested.
 * Credit to RedSpah for noticing this bug.
 *
 * The alignment is done manually: Functions like posix_memalign or _mm_malloc
 * are avoided: To maintain portability, we would have to write a fallback
 * like this anyways, and besides, testing for the existence of library
 * functions without relying on external build tools is impossible.
 *
 * The method is simple: Overallocate, manually align, and store the offset
 * to the original behind the returned pointer.
 *
 * Align must be a power of 2 and 8 <= align <= 128.
 */
static void* XXH_alignedMalloc(size_t s, size_t align)
{
    XXH_ASSERT(align <= 128 && align >= 8); /* range check */
    XXH_ASSERT((align & (align-1)) == 0);   /* power of 2 */
    XXH_ASSERT(s != 0 && s < (s + align));  /* empty/overflow */
    {   /* Overallocate to make room for manual realignment and an offset byte */
        xxh_u8* base = (xxh_u8*)VG_(malloc)("zstddeclib.XXH_alignedMalloc.1",s + align);
        if (base != NULL) {
            /*
             * Get the offset needed to align this pointer.
             *
             * Even if the returned pointer is aligned, there will always be
             * at least one byte to store the offset to the original pointer.
             */
            size_t offset = align - ((size_t)base & (align - 1)); /* base % align */
            /* Add the offset for the now-aligned pointer */
            xxh_u8* ptr = base + offset;

            XXH_ASSERT((size_t)ptr % align == 0);

            /* Store the offset immediately before the returned pointer. */
            ptr[-1] = (xxh_u8)offset;
            return ptr;
        }
        return NULL;
    }
}
/*
 * Frees an aligned pointer allocated by XXH_alignedMalloc(). Don't pass
 * normal malloc'd pointers, XXH_alignedMalloc has a specific data layout.
 */
static void XXH_alignedFree(void* p)
{
    if (p != NULL) {
        xxh_u8* ptr = (xxh_u8*)p;
        /* Get the offset byte we added in VG_(malloc). */
        xxh_u8 offset = ptr[-1];
        /* Free the original malloc'd pointer */
        xxh_u8* base = ptr - offset;
        XXH_free(base);
    }
}
/*! @ingroup XXH3_family */
/*!
 * @brief Allocate an @ref XXH3_state_t.
 *
 * @return An allocated pointer of @ref XXH3_state_t on success.
 * @return `NULL` on failure.
 *
 * @note Must be freed with XXH3_freeState().
 */
XXH_PUBLIC_API XXH3_state_t* XXH3_createState(void)
{
    XXH3_state_t* const state = (XXH3_state_t*)XXH_alignedMalloc(sizeof(XXH3_state_t), 64);
    if (state==NULL) return NULL;
    XXH3_INITSTATE(state);
    return state;
}

/*! @ingroup XXH3_family */
/*!
 * @brief Frees an @ref XXH3_state_t.
 *
 * @param statePtr A pointer to an @ref XXH3_state_t allocated with @ref XXH3_createState().
 *
 * @return @ref XXH_OK.
 *
 * @note Must be allocated with XXH3_createState().
 */
XXH_PUBLIC_API XXH_errorcode XXH3_freeState(XXH3_state_t* statePtr)
{
    XXH_alignedFree(statePtr);
    return XXH_OK;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API void
XXH3_copyState(XXH_NOESCAPE XXH3_state_t* dst_state, XXH_NOESCAPE const XXH3_state_t* src_state)
{
    XXH_memcpy(dst_state, src_state, sizeof(*dst_state));
}

static void
XXH3_reset_internal(XXH3_state_t* statePtr,
                    XXH64_hash_t seed,
                    const void* secret, size_t secretSize)
{
    size_t const initStart = offsetof(XXH3_state_t, bufferedSize);
    size_t const initLength = offsetof(XXH3_state_t, nbStripesPerBlock) - initStart;
    XXH_ASSERT(offsetof(XXH3_state_t, nbStripesPerBlock) > initStart);
    XXH_ASSERT(statePtr != NULL);
    /* set members from bufferedSize to nbStripesPerBlock (excluded) to 0 */
    VG_(memset)((char*)statePtr + initStart, 0, initLength);
    statePtr->acc[0] = XXH_PRIME32_3;
    statePtr->acc[1] = XXH_PRIME64_1;
    statePtr->acc[2] = XXH_PRIME64_2;
    statePtr->acc[3] = XXH_PRIME64_3;
    statePtr->acc[4] = XXH_PRIME64_4;
    statePtr->acc[5] = XXH_PRIME32_2;
    statePtr->acc[6] = XXH_PRIME64_5;
    statePtr->acc[7] = XXH_PRIME32_1;
    statePtr->seed = seed;
    statePtr->useSeed = (seed != 0);
    statePtr->extSecret = (const unsigned char*)secret;
    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
    statePtr->secretLimit = secretSize - XXH_STRIPE_LEN;
    statePtr->nbStripesPerBlock = statePtr->secretLimit / XXH_SECRET_CONSUME_RATE;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset(XXH_NOESCAPE XXH3_state_t* statePtr)
{
    if (statePtr == NULL) return XXH_ERROR;
    XXH3_reset_internal(statePtr, 0, XXH3_kSecret, XXH_SECRET_DEFAULT_SIZE);
    return XXH_OK;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset_withSecret(XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* secret, size_t secretSize)
{
    if (statePtr == NULL) return XXH_ERROR;
    XXH3_reset_internal(statePtr, 0, secret, secretSize);
    if (secret == NULL) return XXH_ERROR;
    if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
    return XXH_OK;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset_withSeed(XXH_NOESCAPE XXH3_state_t* statePtr, XXH64_hash_t seed)
{
    if (statePtr == NULL) return XXH_ERROR;
    if (seed==0) return XXH3_64bits_reset(statePtr);
    if ((seed != statePtr->seed) || (statePtr->extSecret != NULL))
        XXH3_initCustomSecret(statePtr->customSecret, seed);
    XXH3_reset_internal(statePtr, seed, NULL, XXH_SECRET_DEFAULT_SIZE);
    return XXH_OK;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_reset_withSecretandSeed(XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* secret, size_t secretSize, XXH64_hash_t seed64)
{
    if (statePtr == NULL) return XXH_ERROR;
    if (secret == NULL) return XXH_ERROR;
    if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
    XXH3_reset_internal(statePtr, seed64, secret, secretSize);
    statePtr->useSeed = 1; /* always, even if seed64==0 */
    return XXH_OK;
}

/*!
 * @internal
 * @brief Processes a large input for XXH3_update() and XXH3_digest_long().
 *
 * Unlike XXH3_hashLong_internal_loop(), this can process data that overlaps a block.
 *
 * @param acc                Pointer to the 8 accumulator lanes
 * @param nbStripesSoFarPtr  In/out pointer to the number of leftover stripes in the block*
 * @param nbStripesPerBlock  Number of stripes in a block
 * @param input              Input pointer
 * @param nbStripes          Number of stripes to process
 * @param secret             Secret pointer
 * @param secretLimit        Offset of the last block in @p secret
 * @param f_acc              Pointer to an XXH3_accumulate implementation
 * @param f_scramble         Pointer to an XXH3_scrambleAcc implementation
 * @return                   Pointer past the end of @p input after processing
 */
XXH_FORCE_INLINE const xxh_u8 *
XXH3_consumeStripes(xxh_u64* XXH_RESTRICT acc,
                    size_t* XXH_RESTRICT nbStripesSoFarPtr, size_t nbStripesPerBlock,
                    const xxh_u8* XXH_RESTRICT input, size_t nbStripes,
                    const xxh_u8* XXH_RESTRICT secret, size_t secretLimit,
                    XXH3_f_accumulate f_acc,
                    XXH3_f_scrambleAcc f_scramble)
{
    const xxh_u8* initialSecret = secret + *nbStripesSoFarPtr * XXH_SECRET_CONSUME_RATE;
    /* Process full blocks */
    if (nbStripes >= (nbStripesPerBlock - *nbStripesSoFarPtr)) {
        /* Process the initial partial block... */
        size_t nbStripesThisIter = nbStripesPerBlock - *nbStripesSoFarPtr;

        do {
            /* Accumulate and scramble */
            f_acc(acc, input, initialSecret, nbStripesThisIter);
            f_scramble(acc, secret + secretLimit);
            input += nbStripesThisIter * XXH_STRIPE_LEN;
            nbStripes -= nbStripesThisIter;
            /* Then continue the loop with the full block size */
            nbStripesThisIter = nbStripesPerBlock;
            initialSecret = secret;
        } while (nbStripes >= nbStripesPerBlock);
        *nbStripesSoFarPtr = 0;
    }
    /* Process a partial block */
    if (nbStripes > 0) {
        f_acc(acc, input, initialSecret, nbStripes);
        input += nbStripes * XXH_STRIPE_LEN;
        *nbStripesSoFarPtr += nbStripes;
    }
    /* Return end pointer */
    return input;
}

#ifndef XXH3_STREAM_USE_STACK
# if XXH_SIZE_OPT <= 0 && !defined(__clang__) /* clang doesn't need additional stack space */
#   define XXH3_STREAM_USE_STACK 1
# endif
#endif
/*
 * Both XXH3_64bits_update and XXH3_128bits_update use this routine.
 */
XXH_FORCE_INLINE XXH_errorcode
XXH3_update(XXH3_state_t* XXH_RESTRICT const state,
            const xxh_u8* XXH_RESTRICT input, size_t len,
            XXH3_f_accumulate f_acc,
            XXH3_f_scrambleAcc f_scramble)
{
    if (input==NULL) {
        XXH_ASSERT(len == 0);
        return XXH_OK;
    }

    XXH_ASSERT(state != NULL);
    {   const xxh_u8* const bEnd = input + len;
        const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
#if defined(XXH3_STREAM_USE_STACK) && XXH3_STREAM_USE_STACK >= 1
        /* For some reason, gcc and MSVC seem to suffer greatly
         * when operating accumulators directly into state.
         * Operating into stack space seems to enable proper optimization.
         * clang, on the other hand, doesn't seem to need this trick */
        XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[8];
        XXH_memcpy(acc, state->acc, sizeof(acc));
#else
        xxh_u64* XXH_RESTRICT const acc = state->acc;
#endif
        state->totalLen += len;
        XXH_ASSERT(state->bufferedSize <= XXH3_INTERNALBUFFER_SIZE);

        /* small input : just fill in tmp buffer */
        if (len <= XXH3_INTERNALBUFFER_SIZE - state->bufferedSize) {
            XXH_memcpy(state->buffer + state->bufferedSize, input, len);
            state->bufferedSize += (XXH32_hash_t)len;
            return XXH_OK;
        }

        /* total input is now > XXH3_INTERNALBUFFER_SIZE */
        #define XXH3_INTERNALBUFFER_STRIPES (XXH3_INTERNALBUFFER_SIZE / XXH_STRIPE_LEN)
        XXH_STATIC_ASSERT(XXH3_INTERNALBUFFER_SIZE % XXH_STRIPE_LEN == 0);   /* clean multiple */

        /*
         * Internal buffer is partially filled (always, except at beginning)
         * Complete it, then consume it.
         */
        if (state->bufferedSize) {
            size_t const loadSize = XXH3_INTERNALBUFFER_SIZE - state->bufferedSize;
            XXH_memcpy(state->buffer + state->bufferedSize, input, loadSize);
            input += loadSize;
            XXH3_consumeStripes(acc,
                               &state->nbStripesSoFar, state->nbStripesPerBlock,
                                state->buffer, XXH3_INTERNALBUFFER_STRIPES,
                                secret, state->secretLimit,
                                f_acc, f_scramble);
            state->bufferedSize = 0;
        }
        XXH_ASSERT(input < bEnd);
        if (bEnd - input > XXH3_INTERNALBUFFER_SIZE) {
            size_t nbStripes = (size_t)(bEnd - 1 - input) / XXH_STRIPE_LEN;
            input = XXH3_consumeStripes(acc,
                                       &state->nbStripesSoFar, state->nbStripesPerBlock,
                                       input, nbStripes,
                                       secret, state->secretLimit,
                                       f_acc, f_scramble);
            XXH_memcpy(state->buffer + sizeof(state->buffer) - XXH_STRIPE_LEN, input - XXH_STRIPE_LEN, XXH_STRIPE_LEN);

        }
        /* Some remaining input (always) : buffer it */
        XXH_ASSERT(input < bEnd);
        XXH_ASSERT(bEnd - input <= XXH3_INTERNALBUFFER_SIZE);
        XXH_ASSERT(state->bufferedSize == 0);
        XXH_memcpy(state->buffer, input, (size_t)(bEnd-input));
        state->bufferedSize = (XXH32_hash_t)(bEnd-input);
#if defined(XXH3_STREAM_USE_STACK) && XXH3_STREAM_USE_STACK >= 1
        /* save stack accumulators into state */
        XXH_memcpy(state->acc, acc, sizeof(acc));
#endif
    }

    return XXH_OK;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_64bits_update(XXH_NOESCAPE XXH3_state_t* state, XXH_NOESCAPE const void* input, size_t len)
{
    return XXH3_update(state, (const xxh_u8*)input, len,
                       XXH3_accumulate, XXH3_scrambleAcc);
}


XXH_FORCE_INLINE void
XXH3_digest_long (XXH64_hash_t* acc,
                  const XXH3_state_t* state,
                  const unsigned char* secret)
{
    xxh_u8 lastStripe[XXH_STRIPE_LEN];
    const xxh_u8* lastStripePtr;

    /*
     * Digest on a local copy. This way, the state remains unaltered, and it can
     * continue ingesting more input afterwards.
     */
    XXH_memcpy(acc, state->acc, sizeof(state->acc));
    if (state->bufferedSize >= XXH_STRIPE_LEN) {
        /* Consume remaining stripes then point to remaining data in buffer */
        size_t const nbStripes = (state->bufferedSize - 1) / XXH_STRIPE_LEN;
        size_t nbStripesSoFar = state->nbStripesSoFar;
        XXH3_consumeStripes(acc,
                           &nbStripesSoFar, state->nbStripesPerBlock,
                            state->buffer, nbStripes,
                            secret, state->secretLimit,
                            XXH3_accumulate, XXH3_scrambleAcc);
        lastStripePtr = state->buffer + state->bufferedSize - XXH_STRIPE_LEN;
    } else {  /* bufferedSize < XXH_STRIPE_LEN */
        /* Copy to temp buffer */
        size_t const catchupSize = XXH_STRIPE_LEN - state->bufferedSize;
        XXH_ASSERT(state->bufferedSize > 0);  /* there is always some input buffered */
        XXH_memcpy(lastStripe, state->buffer + sizeof(state->buffer) - catchupSize, catchupSize);
        XXH_memcpy(lastStripe + catchupSize, state->buffer, state->bufferedSize);
        lastStripePtr = lastStripe;
    }
    /* Last stripe */
    XXH3_accumulate_512(acc,
                        lastStripePtr,
                        secret + state->secretLimit - XXH_SECRET_LASTACC_START);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH64_hash_t XXH3_64bits_digest (XXH_NOESCAPE const XXH3_state_t* state)
{
    const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
    if (state->totalLen > XXH3_MIDSIZE_MAX) {
        XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
        XXH3_digest_long(acc, state, secret);
        return XXH3_mergeAccs(acc,
                              secret + XXH_SECRET_MERGEACCS_START,
                              (xxh_u64)state->totalLen * XXH_PRIME64_1);
    }
    /* totalLen <= XXH3_MIDSIZE_MAX: digesting a short input */
    if (state->useSeed)
        return XXH3_64bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
    return XXH3_64bits_withSecret(state->buffer, (size_t)(state->totalLen),
                                  secret, state->secretLimit + XXH_STRIPE_LEN);
}
#endif /* !XXH_NO_STREAM */


/* ==========================================
 * XXH3 128 bits (a.k.a XXH128)
 * ==========================================
 * XXH3's 128-bit variant has better mixing and strength than the 64-bit variant,
 * even without counting the significantly larger output size.
 *
 * For example, extra steps are taken to avoid the seed-dependent collisions
 * in 17-240 byte inputs (See XXH3_mix16B and XXH128_mix32B).
 *
 * This strength naturally comes at the cost of some speed, especially on short
 * lengths. Note that longer hashes are about as fast as the 64-bit version
 * due to it using only a slight modification of the 64-bit loop.
 *
 * XXH128 is also more oriented towards 64-bit machines. It is still extremely
 * fast for a _128-bit_ hash on 32-bit (it usually clears XXH64).
 */

XXH_FORCE_INLINE XXH_PUREF XXH128_hash_t
XXH3_len_1to3_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    /* A doubled version of 1to3_64b with different constants. */
    XXH_ASSERT(input != NULL);
    XXH_ASSERT(1 <= len && len <= 3);
    XXH_ASSERT(secret != NULL);
    /*
     * len = 1: combinedl = { input[0], 0x01, input[0], input[0] }
     * len = 2: combinedl = { input[1], 0x02, input[0], input[1] }
     * len = 3: combinedl = { input[2], 0x03, input[0], input[1] }
     */
    {   xxh_u8 const c1 = input[0];
        xxh_u8 const c2 = input[len >> 1];
        xxh_u8 const c3 = input[len - 1];
        xxh_u32 const combinedl = ((xxh_u32)c1 <<16) | ((xxh_u32)c2 << 24)
                                | ((xxh_u32)c3 << 0) | ((xxh_u32)len << 8);
        xxh_u32 const combinedh = XXH_rotl32(XXH_swap32(combinedl), 13);
        xxh_u64 const bitflipl = (XXH_readLE32(secret) ^ XXH_readLE32(secret+4)) + seed;
        xxh_u64 const bitfliph = (XXH_readLE32(secret+8) ^ XXH_readLE32(secret+12)) - seed;
        xxh_u64 const keyed_lo = (xxh_u64)combinedl ^ bitflipl;
        xxh_u64 const keyed_hi = (xxh_u64)combinedh ^ bitfliph;
        XXH128_hash_t h128;
        h128.low64  = XXH64_avalanche(keyed_lo);
        h128.high64 = XXH64_avalanche(keyed_hi);
        return h128;
    }
}

XXH_FORCE_INLINE XXH_PUREF XXH128_hash_t
XXH3_len_4to8_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(input != NULL);
    XXH_ASSERT(secret != NULL);
    XXH_ASSERT(4 <= len && len <= 8);
    seed ^= (xxh_u64)XXH_swap32((xxh_u32)seed) << 32;
    {   xxh_u32 const input_lo = XXH_readLE32(input);
        xxh_u32 const input_hi = XXH_readLE32(input + len - 4);
        xxh_u64 const input_64 = input_lo + ((xxh_u64)input_hi << 32);
        xxh_u64 const bitflip = (XXH_readLE64(secret+16) ^ XXH_readLE64(secret+24)) + seed;
        xxh_u64 const keyed = input_64 ^ bitflip;

        /* Shift len to the left to ensure it is even, this avoids even multiplies. */
        XXH128_hash_t m128 = XXH_mult64to128(keyed, XXH_PRIME64_1 + (len << 2));

        m128.high64 += (m128.low64 << 1);
        m128.low64  ^= (m128.high64 >> 3);

        m128.low64   = XXH_xorshift64(m128.low64, 35);
        m128.low64  *= PRIME_MX2;
        m128.low64   = XXH_xorshift64(m128.low64, 28);
        m128.high64  = XXH3_avalanche(m128.high64);
        return m128;
    }
}

XXH_FORCE_INLINE XXH_PUREF XXH128_hash_t
XXH3_len_9to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(input != NULL);
    XXH_ASSERT(secret != NULL);
    XXH_ASSERT(9 <= len && len <= 16);
    {   xxh_u64 const bitflipl = (XXH_readLE64(secret+32) ^ XXH_readLE64(secret+40)) - seed;
        xxh_u64 const bitfliph = (XXH_readLE64(secret+48) ^ XXH_readLE64(secret+56)) + seed;
        xxh_u64 const input_lo = XXH_readLE64(input);
        xxh_u64       input_hi = XXH_readLE64(input + len - 8);
        XXH128_hash_t m128 = XXH_mult64to128(input_lo ^ input_hi ^ bitflipl, XXH_PRIME64_1);
        /*
         * Put len in the middle of m128 to ensure that the length gets mixed to
         * both the low and high bits in the 128x64 multiply below.
         */
        m128.low64 += (xxh_u64)(len - 1) << 54;
        input_hi   ^= bitfliph;
        /*
         * Add the high 32 bits of input_hi to the high 32 bits of m128, then
         * add the long product of the low 32 bits of input_hi and XXH_PRIME32_2 to
         * the high 64 bits of m128.
         *
         * The best approach to this operation is different on 32-bit and 64-bit.
         */
        if (sizeof(void *) < sizeof(xxh_u64)) { /* 32-bit */
            /*
             * 32-bit optimized version, which is more readable.
             *
             * On 32-bit, it removes an ADC and delays a dependency between the two
             * halves of m128.high64, but it generates an extra mask on 64-bit.
             */
            m128.high64 += (input_hi & 0xFFFFFFFF00000000ULL) + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2);
        } else {
            /*
             * 64-bit optimized (albeit more confusing) version.
             *
             * Uses some properties of addition and multiplication to remove the mask:
             *
             * Let:
             *    a = input_hi.lo = (input_hi & 0x00000000FFFFFFFF)
             *    b = input_hi.hi = (input_hi & 0xFFFFFFFF00000000)
             *    c = XXH_PRIME32_2
             *
             *    a + (b * c)
             * Inverse Property: x + y - x == y
             *    a + (b * (1 + c - 1))
             * Distributive Property: x * (y + z) == (x * y) + (x * z)
             *    a + (b * 1) + (b * (c - 1))
             * Identity Property: x * 1 == x
             *    a + b + (b * (c - 1))
             *
             * Substitute a, b, and c:
             *    input_hi.hi + input_hi.lo + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
             *
             * Since input_hi.hi + input_hi.lo == input_hi, we get this:
             *    input_hi + ((xxh_u64)input_hi.lo * (XXH_PRIME32_2 - 1))
             */
            m128.high64 += input_hi + XXH_mult32to64((xxh_u32)input_hi, XXH_PRIME32_2 - 1);
        }
        /* m128 ^= XXH_swap64(m128 >> 64); */
        m128.low64  ^= XXH_swap64(m128.high64);

        {   /* 128x64 multiply: h128 = m128 * XXH_PRIME64_2; */
            XXH128_hash_t h128 = XXH_mult64to128(m128.low64, XXH_PRIME64_2);
            h128.high64 += m128.high64 * XXH_PRIME64_2;

            h128.low64   = XXH3_avalanche(h128.low64);
            h128.high64  = XXH3_avalanche(h128.high64);
            return h128;
    }   }
}

/*
 * Assumption: `secret` size is >= XXH3_SECRET_SIZE_MIN
 */
XXH_FORCE_INLINE XXH_PUREF XXH128_hash_t
XXH3_len_0to16_128b(const xxh_u8* input, size_t len, const xxh_u8* secret, XXH64_hash_t seed)
{
    XXH_ASSERT(len <= 16);
    {   if (len > 8) return XXH3_len_9to16_128b(input, len, secret, seed);
        if (len >= 4) return XXH3_len_4to8_128b(input, len, secret, seed);
        if (len) return XXH3_len_1to3_128b(input, len, secret, seed);
        {   XXH128_hash_t h128;
            xxh_u64 const bitflipl = XXH_readLE64(secret+64) ^ XXH_readLE64(secret+72);
            xxh_u64 const bitfliph = XXH_readLE64(secret+80) ^ XXH_readLE64(secret+88);
            h128.low64 = XXH64_avalanche(seed ^ bitflipl);
            h128.high64 = XXH64_avalanche( seed ^ bitfliph);
            return h128;
    }   }
}

/*
 * A bit slower than XXH3_mix16B, but handles multiply by zero better.
 */
XXH_FORCE_INLINE XXH128_hash_t
XXH128_mix32B(XXH128_hash_t acc, const xxh_u8* input_1, const xxh_u8* input_2,
              const xxh_u8* secret, XXH64_hash_t seed)
{
    acc.low64  += XXH3_mix16B (input_1, secret+0, seed);
    acc.low64  ^= XXH_readLE64(input_2) + XXH_readLE64(input_2 + 8);
    acc.high64 += XXH3_mix16B (input_2, secret+16, seed);
    acc.high64 ^= XXH_readLE64(input_1) + XXH_readLE64(input_1 + 8);
    return acc;
}


XXH_FORCE_INLINE XXH_PUREF XXH128_hash_t
XXH3_len_17to128_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
                      const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
                      XXH64_hash_t seed)
{
    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
    XXH_ASSERT(16 < len && len <= 128);

    {   XXH128_hash_t acc;
        acc.low64 = len * XXH_PRIME64_1;
        acc.high64 = 0;

#if XXH_SIZE_OPT >= 1
        {
            /* Smaller, but slightly slower. */
            unsigned int i = (unsigned int)(len - 1) / 32;
            do {
                acc = XXH128_mix32B(acc, input+16*i, input+len-16*(i+1), secret+32*i, seed);
            } while (i-- != 0);
        }
#else
        if (len > 32) {
            if (len > 64) {
                if (len > 96) {
                    acc = XXH128_mix32B(acc, input+48, input+len-64, secret+96, seed);
                }
                acc = XXH128_mix32B(acc, input+32, input+len-48, secret+64, seed);
            }
            acc = XXH128_mix32B(acc, input+16, input+len-32, secret+32, seed);
        }
        acc = XXH128_mix32B(acc, input, input+len-16, secret, seed);
#endif
        {   XXH128_hash_t h128;
            h128.low64  = acc.low64 + acc.high64;
            h128.high64 = (acc.low64    * XXH_PRIME64_1)
                        + (acc.high64   * XXH_PRIME64_4)
                        + ((len - seed) * XXH_PRIME64_2);
            h128.low64  = XXH3_avalanche(h128.low64);
            h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
            return h128;
        }
    }
}

XXH_NO_INLINE XXH_PUREF XXH128_hash_t
XXH3_len_129to240_128b(const xxh_u8* XXH_RESTRICT input, size_t len,
                       const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
                       XXH64_hash_t seed)
{
    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN); (void)secretSize;
    XXH_ASSERT(128 < len && len <= XXH3_MIDSIZE_MAX);

    {   XXH128_hash_t acc;
        unsigned i;
        acc.low64 = len * XXH_PRIME64_1;
        acc.high64 = 0;
        /*
         *  We set as `i` as offset + 32. We do this so that unchanged
         * `len` can be used as upper bound. This reaches a sweet spot
         * where both x86 and aarch64 get simple agen and good codegen
         * for the loop.
         */
        for (i = 32; i < 160; i += 32) {
            acc = XXH128_mix32B(acc,
                                input  + i - 32,
                                input  + i - 16,
                                secret + i - 32,
                                seed);
        }
        acc.low64 = XXH3_avalanche(acc.low64);
        acc.high64 = XXH3_avalanche(acc.high64);
        /*
         * NB: `i <= len` will duplicate the last 32-bytes if
         * len % 32 was zero. This is an unfortunate necessity to keep
         * the hash result stable.
         */
        for (i=160; i <= len; i += 32) {
            acc = XXH128_mix32B(acc,
                                input + i - 32,
                                input + i - 16,
                                secret + XXH3_MIDSIZE_STARTOFFSET + i - 160,
                                seed);
        }
        /* last bytes */
        acc = XXH128_mix32B(acc,
                            input + len - 16,
                            input + len - 32,
                            secret + XXH3_SECRET_SIZE_MIN - XXH3_MIDSIZE_LASTOFFSET - 16,
                            (XXH64_hash_t)0 - seed);

        {   XXH128_hash_t h128;
            h128.low64  = acc.low64 + acc.high64;
            h128.high64 = (acc.low64    * XXH_PRIME64_1)
                        + (acc.high64   * XXH_PRIME64_4)
                        + ((len - seed) * XXH_PRIME64_2);
            h128.low64  = XXH3_avalanche(h128.low64);
            h128.high64 = (XXH64_hash_t)0 - XXH3_avalanche(h128.high64);
            return h128;
        }
    }
}

XXH_FORCE_INLINE XXH128_hash_t
XXH3_hashLong_128b_internal(const void* XXH_RESTRICT input, size_t len,
                            const xxh_u8* XXH_RESTRICT secret, size_t secretSize,
                            XXH3_f_accumulate f_acc,
                            XXH3_f_scrambleAcc f_scramble)
{
    XXH_ALIGN(XXH_ACC_ALIGN) xxh_u64 acc[XXH_ACC_NB] = XXH3_INIT_ACC;

    XXH3_hashLong_internal_loop(acc, (const xxh_u8*)input, len, secret, secretSize, f_acc, f_scramble);

    /* converge into final hash */
    XXH_STATIC_ASSERT(sizeof(acc) == 64);
    XXH_ASSERT(secretSize >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
    {   XXH128_hash_t h128;
        h128.low64  = XXH3_mergeAccs(acc,
                                     secret + XXH_SECRET_MERGEACCS_START,
                                     (xxh_u64)len * XXH_PRIME64_1);
        h128.high64 = XXH3_mergeAccs(acc,
                                     secret + secretSize
                                            - sizeof(acc) - XXH_SECRET_MERGEACCS_START,
                                     ~((xxh_u64)len * XXH_PRIME64_2));
        return h128;
    }
}

/*
 * It's important for performance that XXH3_hashLong() is not inlined.
 */
XXH_NO_INLINE XXH_PUREF XXH128_hash_t
XXH3_hashLong_128b_default(const void* XXH_RESTRICT input, size_t len,
                           XXH64_hash_t seed64,
                           const void* XXH_RESTRICT secret, size_t secretLen)
{
    (void)seed64; (void)secret; (void)secretLen;
    return XXH3_hashLong_128b_internal(input, len, XXH3_kSecret, sizeof(XXH3_kSecret),
                                       XXH3_accumulate, XXH3_scrambleAcc);
}

/*
 * It's important for performance to pass @p secretLen (when it's static)
 * to the compiler, so that it can properly optimize the vectorized loop.
 *
 * When the secret size is unknown, or on GCC 12 where the mix of NO_INLINE and FORCE_INLINE
 * breaks -Og, this is XXH_NO_INLINE.
 */
XXH3_WITH_SECRET_INLINE XXH128_hash_t
XXH3_hashLong_128b_withSecret(const void* XXH_RESTRICT input, size_t len,
                              XXH64_hash_t seed64,
                              const void* XXH_RESTRICT secret, size_t secretLen)
{
    (void)seed64;
    return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, secretLen,
                                       XXH3_accumulate, XXH3_scrambleAcc);
}

XXH_FORCE_INLINE XXH128_hash_t
XXH3_hashLong_128b_withSeed_internal(const void* XXH_RESTRICT input, size_t len,
                                XXH64_hash_t seed64,
                                XXH3_f_accumulate f_acc,
                                XXH3_f_scrambleAcc f_scramble,
                                XXH3_f_initCustomSecret f_initSec)
{
    if (seed64 == 0)
        return XXH3_hashLong_128b_internal(input, len,
                                           XXH3_kSecret, sizeof(XXH3_kSecret),
                                           f_acc, f_scramble);
    {   XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
        f_initSec(secret, seed64);
        return XXH3_hashLong_128b_internal(input, len, (const xxh_u8*)secret, sizeof(secret),
                                           f_acc, f_scramble);
    }
}

/*
 * It's important for performance that XXH3_hashLong is not inlined.
 */
XXH_NO_INLINE XXH128_hash_t
XXH3_hashLong_128b_withSeed(const void* input, size_t len,
                            XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen)
{
    (void)secret; (void)secretLen;
    return XXH3_hashLong_128b_withSeed_internal(input, len, seed64,
                XXH3_accumulate, XXH3_scrambleAcc, XXH3_initCustomSecret);
}

typedef XXH128_hash_t (*XXH3_hashLong128_f)(const void* XXH_RESTRICT, size_t,
                                            XXH64_hash_t, const void* XXH_RESTRICT, size_t);

XXH_FORCE_INLINE XXH128_hash_t
XXH3_128bits_internal(const void* input, size_t len,
                      XXH64_hash_t seed64, const void* XXH_RESTRICT secret, size_t secretLen,
                      XXH3_hashLong128_f f_hl128)
{
    XXH_ASSERT(secretLen >= XXH3_SECRET_SIZE_MIN);
    /*
     * If an action is to be taken if `secret` conditions are not respected,
     * it should be done here.
     * For now, it's a contract pre-condition.
     * Adding a check and a branch here would cost performance at every hash.
     */
    if (len <= 16)
        return XXH3_len_0to16_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, seed64);
    if (len <= 128)
        return XXH3_len_17to128_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
    if (len <= XXH3_MIDSIZE_MAX)
        return XXH3_len_129to240_128b((const xxh_u8*)input, len, (const xxh_u8*)secret, secretLen, seed64);
    return f_hl128(input, len, seed64, secret, secretLen);
}


/* ===   Public XXH128 API   === */

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits(XXH_NOESCAPE const void* input, size_t len)
{
    return XXH3_128bits_internal(input, len, 0,
                                 XXH3_kSecret, sizeof(XXH3_kSecret),
                                 XXH3_hashLong_128b_default);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t
XXH3_128bits_withSecret(XXH_NOESCAPE const void* input, size_t len, XXH_NOESCAPE const void* secret, size_t secretSize)
{
    return XXH3_128bits_internal(input, len, 0,
                                 (const xxh_u8*)secret, secretSize,
                                 XXH3_hashLong_128b_withSecret);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t
XXH3_128bits_withSeed(XXH_NOESCAPE const void* input, size_t len, XXH64_hash_t seed)
{
    return XXH3_128bits_internal(input, len, seed,
                                 XXH3_kSecret, sizeof(XXH3_kSecret),
                                 XXH3_hashLong_128b_withSeed);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t
XXH3_128bits_withSecretandSeed(XXH_NOESCAPE const void* input, size_t len, XXH_NOESCAPE const void* secret, size_t secretSize, XXH64_hash_t seed)
{
    if (len <= XXH3_MIDSIZE_MAX)
        return XXH3_128bits_internal(input, len, seed, XXH3_kSecret, sizeof(XXH3_kSecret), NULL);
    return XXH3_hashLong_128b_withSecret(input, len, seed, secret, secretSize);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t
XXH128(XXH_NOESCAPE const void* input, size_t len, XXH64_hash_t seed)
{
    return XXH3_128bits_withSeed(input, len, seed);
}


/* ===   XXH3 128-bit streaming   === */
#ifndef XXH_NO_STREAM
/*
 * All initialization and update functions are identical to 64-bit streaming variant.
 * The only difference is the finalization routine.
 */

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset(XXH_NOESCAPE XXH3_state_t* statePtr)
{
    return XXH3_64bits_reset(statePtr);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset_withSecret(XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* secret, size_t secretSize)
{
    return XXH3_64bits_reset_withSecret(statePtr, secret, secretSize);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset_withSeed(XXH_NOESCAPE XXH3_state_t* statePtr, XXH64_hash_t seed)
{
    return XXH3_64bits_reset_withSeed(statePtr, seed);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_reset_withSecretandSeed(XXH_NOESCAPE XXH3_state_t* statePtr, XXH_NOESCAPE const void* secret, size_t secretSize, XXH64_hash_t seed)
{
    return XXH3_64bits_reset_withSecretandSeed(statePtr, secret, secretSize, seed);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_128bits_update(XXH_NOESCAPE XXH3_state_t* state, XXH_NOESCAPE const void* input, size_t len)
{
    return XXH3_64bits_update(state, input, len);
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t XXH3_128bits_digest (XXH_NOESCAPE const XXH3_state_t* state)
{
    const unsigned char* const secret = (state->extSecret == NULL) ? state->customSecret : state->extSecret;
    if (state->totalLen > XXH3_MIDSIZE_MAX) {
        XXH_ALIGN(XXH_ACC_ALIGN) XXH64_hash_t acc[XXH_ACC_NB];
        XXH3_digest_long(acc, state, secret);
        XXH_ASSERT(state->secretLimit + XXH_STRIPE_LEN >= sizeof(acc) + XXH_SECRET_MERGEACCS_START);
        {   XXH128_hash_t h128;
            h128.low64  = XXH3_mergeAccs(acc,
                                         secret + XXH_SECRET_MERGEACCS_START,
                                         (xxh_u64)state->totalLen * XXH_PRIME64_1);
            h128.high64 = XXH3_mergeAccs(acc,
                                         secret + state->secretLimit + XXH_STRIPE_LEN
                                                - sizeof(acc) - XXH_SECRET_MERGEACCS_START,
                                         ~((xxh_u64)state->totalLen * XXH_PRIME64_2));
            return h128;
        }
    }
    /* len <= XXH3_MIDSIZE_MAX : short code */
    if (state->seed)
        return XXH3_128bits_withSeed(state->buffer, (size_t)state->totalLen, state->seed);
    return XXH3_128bits_withSecret(state->buffer, (size_t)(state->totalLen),
                                   secret, state->secretLimit + XXH_STRIPE_LEN);
}
#endif /* !XXH_NO_STREAM */
/* 128-bit utility functions */

#include <string.h>   /* memcmp, memcpy */

/* return : 1 is equal, 0 if different */
/*! @ingroup XXH3_family */
XXH_PUBLIC_API int XXH128_isEqual(XXH128_hash_t h1, XXH128_hash_t h2)
{
    /* note : XXH128_hash_t is compact, it has no padding byte */
    return !(memcmp(&h1, &h2, sizeof(h1)));
}

/* This prototype is compatible with stdlib's qsort().
 * @return : >0 if *h128_1  > *h128_2
 *           <0 if *h128_1  < *h128_2
 *           =0 if *h128_1 == *h128_2  */
/*! @ingroup XXH3_family */
XXH_PUBLIC_API int XXH128_cmp(XXH_NOESCAPE const void* h128_1, XXH_NOESCAPE const void* h128_2)
{
    XXH128_hash_t const h1 = *(const XXH128_hash_t*)h128_1;
    XXH128_hash_t const h2 = *(const XXH128_hash_t*)h128_2;
    int const hcmp = (h1.high64 > h2.high64) - (h2.high64 > h1.high64);
    /* note : bets that, in most cases, hash values are different */
    if (hcmp) return hcmp;
    return (h1.low64 > h2.low64) - (h2.low64 > h1.low64);
}


/*======   Canonical representation   ======*/
/*! @ingroup XXH3_family */
XXH_PUBLIC_API void
XXH128_canonicalFromHash(XXH_NOESCAPE XXH128_canonical_t* dst, XXH128_hash_t hash)
{
    XXH_STATIC_ASSERT(sizeof(XXH128_canonical_t) == sizeof(XXH128_hash_t));
    if (XXH_CPU_LITTLE_ENDIAN) {
        hash.high64 = XXH_swap64(hash.high64);
        hash.low64  = XXH_swap64(hash.low64);
    }
    XXH_memcpy(dst, &hash.high64, sizeof(hash.high64));
    XXH_memcpy((char*)dst + sizeof(hash.high64), &hash.low64, sizeof(hash.low64));
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH128_hash_t
XXH128_hashFromCanonical(XXH_NOESCAPE const XXH128_canonical_t* src)
{
    XXH128_hash_t h;
    h.high64 = XXH_readBE64(src);
    h.low64  = XXH_readBE64(src->digest + 8);
    return h;
}



/* ==========================================
 * Secret generators
 * ==========================================
 */
#define XXH_MIN(x, y) (((x) > (y)) ? (y) : (x))

XXH_FORCE_INLINE void XXH3_combine16(void* dst, XXH128_hash_t h128)
{
    XXH_writeLE64( dst, XXH_readLE64(dst) ^ h128.low64 );
    XXH_writeLE64( (char*)dst+8, XXH_readLE64((char*)dst+8) ^ h128.high64 );
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API XXH_errorcode
XXH3_generateSecret(XXH_NOESCAPE void* secretBuffer, size_t secretSize, XXH_NOESCAPE const void* customSeed, size_t customSeedSize)
{
#if (XXH_DEBUGLEVEL >= 1)
    XXH_ASSERT(secretBuffer != NULL);
    XXH_ASSERT(secretSize >= XXH3_SECRET_SIZE_MIN);
#else
    /* production mode, assert() are disabled */
    if (secretBuffer == NULL) return XXH_ERROR;
    if (secretSize < XXH3_SECRET_SIZE_MIN) return XXH_ERROR;
#endif

    if (customSeedSize == 0) {
        customSeed = XXH3_kSecret;
        customSeedSize = XXH_SECRET_DEFAULT_SIZE;
    }
#if (XXH_DEBUGLEVEL >= 1)
    XXH_ASSERT(customSeed != NULL);
#else
    if (customSeed == NULL) return XXH_ERROR;
#endif

    /* Fill secretBuffer with a copy of customSeed - repeat as needed */
    {   size_t pos = 0;
        while (pos < secretSize) {
            size_t const toCopy = XXH_MIN((secretSize - pos), customSeedSize);
            memcpy((char*)secretBuffer + pos, customSeed, toCopy);
            pos += toCopy;
    }   }

    {   size_t const nbSeg16 = secretSize / 16;
        size_t n;
        XXH128_canonical_t scrambler;
        XXH128_canonicalFromHash(&scrambler, XXH128(customSeed, customSeedSize, 0));
        for (n=0; n<nbSeg16; n++) {
            XXH128_hash_t const h128 = XXH128(&scrambler, sizeof(scrambler), n);
            XXH3_combine16((char*)secretBuffer + n*16, h128);
        }
        /* last segment */
        XXH3_combine16((char*)secretBuffer + secretSize - 16, XXH128_hashFromCanonical(&scrambler));
    }
    return XXH_OK;
}

/*! @ingroup XXH3_family */
XXH_PUBLIC_API void
XXH3_generateSecret_fromSeed(XXH_NOESCAPE void* secretBuffer, XXH64_hash_t seed)
{
    XXH_ALIGN(XXH_SEC_ALIGN) xxh_u8 secret[XXH_SECRET_DEFAULT_SIZE];
    XXH3_initCustomSecret(secret, seed);
    XXH_ASSERT(secretBuffer != NULL);
    memcpy(secretBuffer, secret, XXH_SECRET_DEFAULT_SIZE);
}



/* Pop our optimization override from above */
#if XXH_VECTOR == XXH_AVX2 /* AVX2 */ \
  && defined(__GNUC__) && !defined(__clang__) /* GCC, not Clang */ \
  && defined(__OPTIMIZE__) && XXH_SIZE_OPT <= 0 /* respect -O0 and -Os */
#  pragma GCC pop_options
#endif

#endif  /* XXH_NO_LONG_LONG */

#endif  /* XXH_NO_XXH3 */

/*!
 * @}
 */
#endif  /* XXH_IMPLEMENTATION */


#if defined (__cplusplus)
} /* extern "C" */
#endif
/**** ended inlining xxhash.h ****/
#ifndef ZSTD_NO_TRACE
/**** start inlining zstd_trace.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

#ifndef ZSTD_TRACE_H
#define ZSTD_TRACE_H

#if defined (__cplusplus)
extern "C" {
#endif

#include <stddef.h>

/* weak symbol support
 * For now, enable conservatively:
 * - Only GNUC
 * - Only ELF
 * - Only x86-64, i386 and aarch64
 * Also, explicitly disable on platforms known not to work so they aren't
 * forgotten in the future.
 */
#if !defined(ZSTD_HAVE_WEAK_SYMBOLS) && \
    defined(__GNUC__) && defined(__ELF__) && \
    (defined(__x86_64__) || defined(_M_X64) || defined(__i386__) || defined(_M_IX86) || defined(__aarch64__)) && \
    !defined(__APPLE__) && !defined(_WIN32) && !defined(__MINGW32__) && \
    !defined(__CYGWIN__) && !defined(_AIX)
#  define ZSTD_HAVE_WEAK_SYMBOLS 1
#else
#  define ZSTD_HAVE_WEAK_SYMBOLS 0
#endif
#if ZSTD_HAVE_WEAK_SYMBOLS
#  define ZSTD_WEAK_ATTR __attribute__((__weak__))
#else
#  define ZSTD_WEAK_ATTR
#endif

/* Only enable tracing when weak symbols are available. */
#ifndef ZSTD_TRACE
#  define ZSTD_TRACE ZSTD_HAVE_WEAK_SYMBOLS
#endif

#if ZSTD_TRACE

struct ZSTD_CCtx_s;
struct ZSTD_DCtx_s;
struct ZSTD_CCtx_params_s;

typedef struct {
    /**
     * ZSTD_VERSION_NUMBER
     *
     * This is guaranteed to be the first member of ZSTD_trace.
     * Otherwise, this struct is not stable between versions. If
     * the version number does not match your expectation, you
     * should not interpret the rest of the struct.
     */
    unsigned version;
    /**
     * Non-zero if streaming (de)compression is used.
     */
    unsigned streaming;
    /**
     * The dictionary ID.
     */
    unsigned dictionaryID;
    /**
     * Is the dictionary cold?
     * Only set on decompression.
     */
    unsigned dictionaryIsCold;
    /**
     * The dictionary size or zero if no dictionary.
     */
    size_t dictionarySize;
    /**
     * The uncompressed size of the data.
     */
    size_t uncompressedSize;
    /**
     * The compressed size of the data.
     */
    size_t compressedSize;
    /**
     * The fully resolved CCtx parameters (NULL on decompression).
     */
    struct ZSTD_CCtx_params_s const* params;
    /**
     * The ZSTD_CCtx pointer (NULL on decompression).
     */
    struct ZSTD_CCtx_s const* cctx;
    /**
     * The ZSTD_DCtx pointer (NULL on compression).
     */
    struct ZSTD_DCtx_s const* dctx;
} ZSTD_Trace;

/**
 * A tracing context. It must be 0 when tracing is disabled.
 * Otherwise, any non-zero value returned by a tracing begin()
 * function is presented to any subsequent calls to end().
 *
 * Any non-zero value is treated as tracing is enabled and not
 * interpreted by the library.
 *
 * Two possible uses are:
 * * A timestamp for when the begin() function was called.
 * * A unique key identifying the (de)compression, like the
 *   address of the [dc]ctx pointer if you need to track
 *   more information than just a timestamp.
 */
typedef unsigned long long ZSTD_TraceCtx;

/**
 * Trace the beginning of a compression call.
 * @param cctx The dctx pointer for the compression.
 *             It can be used as a key to map begin() to end().
 * @returns Non-zero if tracing is enabled. The return value is
 *          passed to ZSTD_trace_compress_end().
 */
ZSTD_WEAK_ATTR ZSTD_TraceCtx ZSTD_trace_compress_begin(
    struct ZSTD_CCtx_s const* cctx);

/**
 * Trace the end of a compression call.
 * @param ctx The return value of ZSTD_trace_compress_begin().
 * @param trace The zstd tracing info.
 */
ZSTD_WEAK_ATTR void ZSTD_trace_compress_end(
    ZSTD_TraceCtx ctx,
    ZSTD_Trace const* trace);

/**
 * Trace the beginning of a decompression call.
 * @param dctx The dctx pointer for the decompression.
 *             It can be used as a key to map begin() to end().
 * @returns Non-zero if tracing is enabled. The return value is
 *          passed to ZSTD_trace_compress_end().
 */
ZSTD_WEAK_ATTR ZSTD_TraceCtx ZSTD_trace_decompress_begin(
    struct ZSTD_DCtx_s const* dctx);

/**
 * Trace the end of a decompression call.
 * @param ctx The return value of ZSTD_trace_decompress_begin().
 * @param trace The zstd tracing info.
 */
ZSTD_WEAK_ATTR void ZSTD_trace_decompress_end(
    ZSTD_TraceCtx ctx,
    ZSTD_Trace const* trace);

#endif /* ZSTD_TRACE */

#if defined (__cplusplus)
}
#endif

#endif /* ZSTD_TRACE_H */
/**** ended inlining zstd_trace.h ****/
#else
#  define ZSTD_TRACE 0
#endif

#if defined (__cplusplus)
extern "C" {
#endif

/* ---- static assert (debug) --- */
#define ZSTD_STATIC_ASSERT(c) DEBUG_STATIC_ASSERT(c)
#define ZSTD_isError ERR_isError   /* for inlining */
#define FSE_isError  ERR_isError
#define HUF_isError  ERR_isError


/*-*************************************
*  shared macros
***************************************/
#undef MIN
#undef MAX
#define MIN(a,b) ((a)<(b) ? (a) : (b))
#define MAX(a,b) ((a)>(b) ? (a) : (b))
#define BOUNDED(min,val,max) (MAX(min,MIN(val,max)))


/*-*************************************
*  Common constants
***************************************/
#define ZSTD_OPT_NUM    (1<<12)

#define ZSTD_REP_NUM      3                 /* number of repcodes */
static UNUSED_ATTR const U32 repStartValue[ZSTD_REP_NUM] = { 1, 4, 8 };

#define KB *(1 <<10)
#define MB *(1 <<20)
#define GB *(1U<<30)

#define BIT7 128
#define BIT6  64
#define BIT5  32
#define BIT4  16
#define BIT1   2
#define BIT0   1

#define ZSTD_WINDOWLOG_ABSOLUTEMIN 10
static UNUSED_ATTR const size_t ZSTD_fcs_fieldSize[4] = { 0, 2, 4, 8 };
static UNUSED_ATTR const size_t ZSTD_did_fieldSize[4] = { 0, 1, 2, 4 };

#define ZSTD_FRAMEIDSIZE 4   /* magic number size */

#define ZSTD_BLOCKHEADERSIZE 3   /* C standard doesn't allow `static const` variable to be init using another `static const` variable */
static UNUSED_ATTR const size_t ZSTD_blockHeaderSize = ZSTD_BLOCKHEADERSIZE;
typedef enum { bt_raw, bt_rle, bt_compressed, bt_reserved } blockType_e;

#define ZSTD_FRAMECHECKSUMSIZE 4

#define MIN_SEQUENCES_SIZE 1 /* nbSeq==0 */
#define MIN_CBLOCK_SIZE (1 /*litCSize*/ + 1 /* RLE or RAW */)   /* for a non-null block */
#define MIN_LITERALS_FOR_4_STREAMS 6

typedef enum { set_basic, set_rle, set_compressed, set_repeat } symbolEncodingType_e;

#define LONGNBSEQ 0x7F00

#define MINMATCH 3

#define Litbits  8
#define LitHufLog 11
#define MaxLit ((1<<Litbits) - 1)
#define MaxML   52
#define MaxLL   35
#define DefaultMaxOff 28
#define MaxOff  31
#define MaxSeq MAX(MaxLL, MaxML)   /* Assumption : MaxOff < MaxLL,MaxML */
#define MLFSELog    9
#define LLFSELog    9
#define OffFSELog   8
#define MaxFSELog  MAX(MAX(MLFSELog, LLFSELog), OffFSELog)
#define MaxMLBits 16
#define MaxLLBits 16

#define ZSTD_MAX_HUF_HEADER_SIZE 128 /* header + <= 127 byte tree description */
/* Each table cannot take more than #symbols * FSELog bits */
#define ZSTD_MAX_FSE_HEADERS_SIZE (((MaxML + 1) * MLFSELog + (MaxLL + 1) * LLFSELog + (MaxOff + 1) * OffFSELog + 7) / 8)

static UNUSED_ATTR const U8 LL_bits[MaxLL+1] = {
     0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0,
     1, 1, 1, 1, 2, 2, 3, 3,
     4, 6, 7, 8, 9,10,11,12,
    13,14,15,16
};
static UNUSED_ATTR const S16 LL_defaultNorm[MaxLL+1] = {
     4, 3, 2, 2, 2, 2, 2, 2,
     2, 2, 2, 2, 2, 1, 1, 1,
     2, 2, 2, 2, 2, 2, 2, 2,
     2, 3, 2, 1, 1, 1, 1, 1,
    -1,-1,-1,-1
};
#define LL_DEFAULTNORMLOG 6  /* for static allocation */
static UNUSED_ATTR const U32 LL_defaultNormLog = LL_DEFAULTNORMLOG;

static UNUSED_ATTR const U8 ML_bits[MaxML+1] = {
     0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0,
     0, 0, 0, 0, 0, 0, 0, 0,
     1, 1, 1, 1, 2, 2, 3, 3,
     4, 4, 5, 7, 8, 9,10,11,
    12,13,14,15,16
};
static UNUSED_ATTR const S16 ML_defaultNorm[MaxML+1] = {
     1, 4, 3, 2, 2, 2, 2, 2,
     2, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1,-1,-1,
    -1,-1,-1,-1,-1
};
#define ML_DEFAULTNORMLOG 6  /* for static allocation */
static UNUSED_ATTR const U32 ML_defaultNormLog = ML_DEFAULTNORMLOG;

static UNUSED_ATTR const S16 OF_defaultNorm[DefaultMaxOff+1] = {
     1, 1, 1, 1, 1, 1, 2, 2,
     2, 1, 1, 1, 1, 1, 1, 1,
     1, 1, 1, 1, 1, 1, 1, 1,
    -1,-1,-1,-1,-1
};
#define OF_DEFAULTNORMLOG 5  /* for static allocation */
static UNUSED_ATTR const U32 OF_defaultNormLog = OF_DEFAULTNORMLOG;


/*-*******************************************
*  Shared functions to include for inlining
*********************************************/
static void ZSTD_copy8(void* dst, const void* src) {
#if defined(ZSTD_ARCH_ARM_NEON)
    vst1_u8((uint8_t*)dst, vld1_u8((const uint8_t*)src));
#else
    ZSTD_memcpy(dst, src, 8);
#endif
}
#define COPY8(d,s) do { ZSTD_copy8(d,s); d+=8; s+=8; } while (0)

/* Need to use memmove here since the literal buffer can now be located within
   the dst buffer. In circumstances where the op "catches up" to where the
   literal buffer is, there can be partial overlaps in this call on the final
   copy if the literal is being shifted by less than 16 bytes. */
static void ZSTD_copy16(void* dst, const void* src) {
#if defined(ZSTD_ARCH_ARM_NEON)
    vst1q_u8((uint8_t*)dst, vld1q_u8((const uint8_t*)src));
#elif defined(ZSTD_ARCH_X86_SSE2)
    _mm_storeu_si128((__m128i*)dst, _mm_loadu_si128((const __m128i*)src));
#elif defined(__clang__)
    ZSTD_memmove(dst, src, 16);
#else
    /* ZSTD_memmove is not inlined properly by gcc */
    BYTE copy16_buf[16];
    ZSTD_memcpy(copy16_buf, src, 16);
    ZSTD_memcpy(dst, copy16_buf, 16);
#endif
}
#define COPY16(d,s) do { ZSTD_copy16(d,s); d+=16; s+=16; } while (0)

#define WILDCOPY_OVERLENGTH 32
#define WILDCOPY_VECLEN 16

typedef enum {
    ZSTD_no_overlap,
    ZSTD_overlap_src_before_dst
    /*  ZSTD_overlap_dst_before_src, */
} ZSTD_overlap_e;

/*! ZSTD_wildcopy() :
 *  Custom version of ZSTD_memcpy(), can over read/write up to WILDCOPY_OVERLENGTH bytes (if length==0)
 *  @param ovtype controls the overlap detection
 *         - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart.
 *         - ZSTD_overlap_src_before_dst: The src and dst may overlap, but they MUST be at least 8 bytes apart.
 *           The src buffer must be before the dst buffer.
 */
MEM_STATIC FORCE_INLINE_ATTR
void ZSTD_wildcopy(void* dst, const void* src, ptrdiff_t length, ZSTD_overlap_e const ovtype)
{
    ptrdiff_t diff = (BYTE*)dst - (const BYTE*)src;
    const BYTE* ip = (const BYTE*)src;
    BYTE* op = (BYTE*)dst;
    BYTE* const oend = op + length;

    if (ovtype == ZSTD_overlap_src_before_dst && diff < WILDCOPY_VECLEN) {
        /* Handle short offset copies. */
        do {
            COPY8(op, ip);
        } while (op < oend);
    } else {
        assert(diff >= WILDCOPY_VECLEN || diff <= -WILDCOPY_VECLEN);
        /* Separate out the first COPY16() call because the copy length is
         * almost certain to be short, so the branches have different
         * probabilities. Since it is almost certain to be short, only do
         * one COPY16() in the first call. Then, do two calls per loop since
         * at that point it is more likely to have a high trip count.
         */
        ZSTD_copy16(op, ip);
        if (16 >= length) return;
        op += 16;
        ip += 16;
        do {
            COPY16(op, ip);
            COPY16(op, ip);
        }
        while (op < oend);
    }
}

MEM_STATIC size_t ZSTD_limitCopy(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
    size_t const length = MIN(dstCapacity, srcSize);
    if (length > 0) {
        ZSTD_memcpy(dst, src, length);
    }
    return length;
}

/* define "workspace is too large" as this number of times larger than needed */
#define ZSTD_WORKSPACETOOLARGE_FACTOR 3

/* when workspace is continuously too large
 * during at least this number of times,
 * context's memory usage is considered wasteful,
 * because it's sized to handle a worst case scenario which rarely happens.
 * In which case, resize it down to free some memory */
#define ZSTD_WORKSPACETOOLARGE_MAXDURATION 128

/* Controls whether the input/output buffer is buffered or stable. */
typedef enum {
    ZSTD_bm_buffered = 0,  /* Buffer the input/output */
    ZSTD_bm_stable = 1     /* ZSTD_inBuffer/ZSTD_outBuffer is stable */
} ZSTD_bufferMode_e;


/*-*******************************************
*  Private declarations
*********************************************/
typedef struct seqDef_s {
    U32 offBase;   /* offBase == Offset + ZSTD_REP_NUM, or repcode 1,2,3 */
    U16 litLength;
    U16 mlBase;    /* mlBase == matchLength - MINMATCH */
} seqDef;

/* Controls whether seqStore has a single "long" litLength or matchLength. See seqStore_t. */
typedef enum {
    ZSTD_llt_none = 0,             /* no longLengthType */
    ZSTD_llt_literalLength = 1,    /* represents a long literal */
    ZSTD_llt_matchLength = 2       /* represents a long match */
} ZSTD_longLengthType_e;

typedef struct {
    seqDef* sequencesStart;
    seqDef* sequences;      /* ptr to end of sequences */
    BYTE*  litStart;
    BYTE*  lit;             /* ptr to end of literals */
    BYTE*  llCode;
    BYTE*  mlCode;
    BYTE*  ofCode;
    size_t maxNbSeq;
    size_t maxNbLit;

    /* longLengthPos and longLengthType to allow us to represent either a single litLength or matchLength
     * in the seqStore that has a value larger than U16 (if it exists). To do so, we increment
     * the existing value of the litLength or matchLength by 0x10000.
     */
    ZSTD_longLengthType_e longLengthType;
    U32                   longLengthPos;  /* Index of the sequence to apply long length modification to */
} seqStore_t;

typedef struct {
    U32 litLength;
    U32 matchLength;
} ZSTD_sequenceLength;

/**
 * Returns the ZSTD_sequenceLength for the given sequences. It handles the decoding of long sequences
 * indicated by longLengthPos and longLengthType, and adds MINMATCH back to matchLength.
 */
MEM_STATIC ZSTD_sequenceLength ZSTD_getSequenceLength(seqStore_t const* seqStore, seqDef const* seq)
{
    ZSTD_sequenceLength seqLen;
    seqLen.litLength = seq->litLength;
    seqLen.matchLength = seq->mlBase + MINMATCH;
    if (seqStore->longLengthPos == (U32)(seq - seqStore->sequencesStart)) {
        if (seqStore->longLengthType == ZSTD_llt_literalLength) {
            seqLen.litLength += 0x10000;
        }
        if (seqStore->longLengthType == ZSTD_llt_matchLength) {
            seqLen.matchLength += 0x10000;
        }
    }
    return seqLen;
}

/**
 * Contains the compressed frame size and an upper-bound for the decompressed frame size.
 * Note: before using `compressedSize`, check for errors using ZSTD_isError().
 *       similarly, before using `decompressedBound`, check for errors using:
 *          `decompressedBound != ZSTD_CONTENTSIZE_ERROR`
 */
typedef struct {
    size_t nbBlocks;
    size_t compressedSize;
    unsigned long long decompressedBound;
} ZSTD_frameSizeInfo;   /* decompress & legacy */

const seqStore_t* ZSTD_getSeqStore(const ZSTD_CCtx* ctx);   /* compress & dictBuilder */
int ZSTD_seqToCodes(const seqStore_t* seqStorePtr);   /* compress, dictBuilder, decodeCorpus (shouldn't get its definition from here) */


/* ZSTD_invalidateRepCodes() :
 * ensures next compression will not use repcodes from previous block.
 * Note : only works with regular variant;
 *        do not use with extDict variant ! */
void ZSTD_invalidateRepCodes(ZSTD_CCtx* cctx);   /* zstdmt, adaptive_compression (shouldn't get this definition from here) */


typedef struct {
    blockType_e blockType;
    U32 lastBlock;
    U32 origSize;
} blockProperties_t;   /* declared here for decompress and fullbench */

/*! ZSTD_getcBlockSize() :
 *  Provides the size of compressed block from block header `src` */
/*  Used by: decompress, fullbench */
size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
                          blockProperties_t* bpPtr);

/*! ZSTD_decodeSeqHeaders() :
 *  decode sequence header from src */
/*  Used by: zstd_decompress_block, fullbench */
size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
                       const void* src, size_t srcSize);

/**
 * @returns true iff the CPU supports dynamic BMI2 dispatch.
 */
MEM_STATIC int ZSTD_cpuSupportsBmi2(void)
{
    ZSTD_cpuid_t cpuid = ZSTD_cpuid();
    return ZSTD_cpuid_bmi1(cpuid) && ZSTD_cpuid_bmi2(cpuid);
}

#if defined (__cplusplus)
}
#endif

#endif   /* ZSTD_CCOMMON_H_MODULE */
/**** ended inlining zstd_internal.h ****/


/*-****************************************
*  Version
******************************************/
unsigned ZSTD_versionNumber(void) { return ZSTD_VERSION_NUMBER; }

const char* ZSTD_versionString(void) { return ZSTD_VERSION_STRING; }


/*-****************************************
*  ZSTD Error Management
******************************************/
#undef ZSTD_isError   /* defined within zstd_internal.h */
/*! ZSTD_isError() :
 *  tells if a return value is an error code
 *  symbol is required for external callers */
unsigned ZSTD_isError(size_t code) { return ERR_isError(code); }

/*! ZSTD_getErrorName() :
 *  provides error code string from function result (useful for debugging) */
const char* ZSTD_getErrorName(size_t code) { return ERR_getErrorName(code); }

/*! ZSTD_getError() :
 *  convert a `size_t` function result into a proper ZSTD_errorCode enum */
ZSTD_ErrorCode ZSTD_getErrorCode(size_t code) { return ERR_getErrorCode(code); }

/*! ZSTD_getErrorString() :
 *  provides error code string from enum */
const char* ZSTD_getErrorString(ZSTD_ErrorCode code) { return ERR_getErrorString(code); }
/**** ended inlining common/zstd_common.c ****/

/**** start inlining decompress/huf_decompress.c ****/
/* ******************************************************************
 * huff0 huffman decoder,
 * part of Finite State Entropy library
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 *  You can contact the author at :
 *  - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
****************************************************************** */

/* **************************************************************
*  Dependencies
****************************************************************/
/**** skipping file: ../common/zstd_deps.h ****/
/**** skipping file: ../common/compiler.h ****/
/**** skipping file: ../common/bitstream.h ****/
/**** skipping file: ../common/fse.h ****/
/**** skipping file: ../common/huf.h ****/
/**** skipping file: ../common/error_private.h ****/
/**** skipping file: ../common/zstd_internal.h ****/
/**** skipping file: ../common/bits.h ****/

/* **************************************************************
*  Constants
****************************************************************/

#define HUF_DECODER_FAST_TABLELOG 11

/* **************************************************************
*  Macros
****************************************************************/

#ifdef HUF_DISABLE_FAST_DECODE
# define HUF_ENABLE_FAST_DECODE 0
#else
# define HUF_ENABLE_FAST_DECODE 1
#endif

/* These two optional macros force the use one way or another of the two
 * Huffman decompression implementations. You can't force in both directions
 * at the same time.
 */
#if defined(HUF_FORCE_DECOMPRESS_X1) && \
    defined(HUF_FORCE_DECOMPRESS_X2)
#error "Cannot force the use of the X1 and X2 decoders at the same time!"
#endif

/* When DYNAMIC_BMI2 is enabled, fast decoders are only called when bmi2 is
 * supported at runtime, so we can add the BMI2 target attribute.
 * When it is disabled, we will still get BMI2 if it is enabled statically.
 */
#if DYNAMIC_BMI2
# define HUF_FAST_BMI2_ATTRS BMI2_TARGET_ATTRIBUTE
#else
# define HUF_FAST_BMI2_ATTRS
#endif

#ifdef __cplusplus
# define HUF_EXTERN_C extern "C"
#else
# define HUF_EXTERN_C
#endif
#define HUF_ASM_DECL HUF_EXTERN_C

#if DYNAMIC_BMI2
# define HUF_NEED_BMI2_FUNCTION 1
#else
# define HUF_NEED_BMI2_FUNCTION 0
#endif

/* **************************************************************
*  Error Management
****************************************************************/
#define HUF_isError ERR_isError


/* **************************************************************
*  Byte alignment for workSpace management
****************************************************************/
#define HUF_ALIGN(x, a)         HUF_ALIGN_MASK((x), (a) - 1)
#define HUF_ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))


/* **************************************************************
*  BMI2 Variant Wrappers
****************************************************************/
typedef size_t (*HUF_DecompressUsingDTableFn)(void *dst, size_t dstSize,
                                              const void *cSrc,
                                              size_t cSrcSize,
                                              const HUF_DTable *DTable);

#if DYNAMIC_BMI2

#define HUF_DGEN(fn)                                                        \
                                                                            \
    static size_t fn##_default(                                             \
                  void* dst,  size_t dstSize,                               \
            const void* cSrc, size_t cSrcSize,                              \
            const HUF_DTable* DTable)                                       \
    {                                                                       \
        return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
    }                                                                       \
                                                                            \
    static BMI2_TARGET_ATTRIBUTE size_t fn##_bmi2(                          \
                  void* dst,  size_t dstSize,                               \
            const void* cSrc, size_t cSrcSize,                              \
            const HUF_DTable* DTable)                                       \
    {                                                                       \
        return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
    }                                                                       \
                                                                            \
    static size_t fn(void* dst, size_t dstSize, void const* cSrc,           \
                     size_t cSrcSize, HUF_DTable const* DTable, int flags)  \
    {                                                                       \
        if (flags & HUF_flags_bmi2) {                                       \
            return fn##_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);         \
        }                                                                   \
        return fn##_default(dst, dstSize, cSrc, cSrcSize, DTable);          \
    }

#else

#define HUF_DGEN(fn)                                                        \
    static size_t fn(void* dst, size_t dstSize, void const* cSrc,           \
                     size_t cSrcSize, HUF_DTable const* DTable, int flags)  \
    {                                                                       \
        (void)flags;                                                        \
        return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable);             \
    }

#endif


/*-***************************/
/*  generic DTableDesc       */
/*-***************************/
typedef struct { BYTE maxTableLog; BYTE tableType; BYTE tableLog; BYTE reserved; } DTableDesc;

static DTableDesc HUF_getDTableDesc(const HUF_DTable* table)
{
    DTableDesc dtd;
    ZSTD_memcpy(&dtd, table, sizeof(dtd));
    return dtd;
}

static size_t HUF_initFastDStream(BYTE const* ip) {
    BYTE const lastByte = ip[7];
    size_t const bitsConsumed = lastByte ? 8 - ZSTD_highbit32(lastByte) : 0;
    size_t const value = MEM_readLEST(ip) | 1;
    assert(bitsConsumed <= 8);
    assert(sizeof(size_t) == 8);
    return value << bitsConsumed;
}


/**
 * The input/output arguments to the Huffman fast decoding loop:
 *
 * ip [in/out] - The input pointers, must be updated to reflect what is consumed.
 * op [in/out] - The output pointers, must be updated to reflect what is written.
 * bits [in/out] - The bitstream containers, must be updated to reflect the current state.
 * dt [in] - The decoding table.
 * ilowest [in] - The beginning of the valid range of the input. Decoders may read
 *                down to this pointer. It may be below iend[0].
 * oend [in] - The end of the output stream. op[3] must not cross oend.
 * iend [in] - The end of each input stream. ip[i] may cross iend[i],
 *             as long as it is above ilowest, but that indicates corruption.
 */
typedef struct {
    BYTE const* ip[4];
    BYTE* op[4];
    U64 bits[4];
    void const* dt;
    BYTE const* ilowest;
    BYTE* oend;
    BYTE const* iend[4];
} HUF_DecompressFastArgs;

typedef void (*HUF_DecompressFastLoopFn)(HUF_DecompressFastArgs*);

/**
 * Initializes args for the fast decoding loop.
 * @returns 1 on success
 *          0 if the fallback implementation should be used.
 *          Or an error code on failure.
 */
static size_t HUF_DecompressFastArgs_init(HUF_DecompressFastArgs* args, void* dst, size_t dstSize, void const* src, size_t srcSize, const HUF_DTable* DTable)
{
    void const* dt = DTable + 1;
    U32 const dtLog = HUF_getDTableDesc(DTable).tableLog;

    const BYTE* const istart = (const BYTE*)src;

    BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize);

    /* The fast decoding loop assumes 64-bit little-endian.
     * This condition is false on x32.
     */
    if (!MEM_isLittleEndian() || MEM_32bits())
        return 0;

    /* Avoid nullptr addition */
    if (dstSize == 0)
        return 0;
    assert(dst != NULL);

    /* strict minimum : jump table + 1 byte per stream */
    if (srcSize < 10)
        return ERROR(corruption_detected);

    /* Must have at least 8 bytes per stream because we don't handle initializing smaller bit containers.
     * If table log is not correct at this point, fallback to the old decoder.
     * On small inputs we don't have enough data to trigger the fast loop, so use the old decoder.
     */
    if (dtLog != HUF_DECODER_FAST_TABLELOG)
        return 0;

    /* Read the jump table. */
    {
        size_t const length1 = MEM_readLE16(istart);
        size_t const length2 = MEM_readLE16(istart+2);
        size_t const length3 = MEM_readLE16(istart+4);
        size_t const length4 = srcSize - (length1 + length2 + length3 + 6);
        args->iend[0] = istart + 6;  /* jumpTable */
        args->iend[1] = args->iend[0] + length1;
        args->iend[2] = args->iend[1] + length2;
        args->iend[3] = args->iend[2] + length3;

        /* HUF_initFastDStream() requires this, and this small of an input
         * won't benefit from the ASM loop anyways.
         */
        if (length1 < 8 || length2 < 8 || length3 < 8 || length4 < 8)
            return 0;
        if (length4 > srcSize) return ERROR(corruption_detected);   /* overflow */
    }
    /* ip[] contains the position that is currently loaded into bits[]. */
    args->ip[0] = args->iend[1] - sizeof(U64);
    args->ip[1] = args->iend[2] - sizeof(U64);
    args->ip[2] = args->iend[3] - sizeof(U64);
    args->ip[3] = (BYTE const*)src + srcSize - sizeof(U64);

    /* op[] contains the output pointers. */
    args->op[0] = (BYTE*)dst;
    args->op[1] = args->op[0] + (dstSize+3)/4;
    args->op[2] = args->op[1] + (dstSize+3)/4;
    args->op[3] = args->op[2] + (dstSize+3)/4;

    /* No point to call the ASM loop for tiny outputs. */
    if (args->op[3] >= oend)
        return 0;

    /* bits[] is the bit container.
        * It is read from the MSB down to the LSB.
        * It is shifted left as it is read, and zeros are
        * shifted in. After the lowest valid bit a 1 is
        * set, so that CountTrailingZeros(bits[]) can be used
        * to count how many bits we've consumed.
        */
    args->bits[0] = HUF_initFastDStream(args->ip[0]);
    args->bits[1] = HUF_initFastDStream(args->ip[1]);
    args->bits[2] = HUF_initFastDStream(args->ip[2]);
    args->bits[3] = HUF_initFastDStream(args->ip[3]);

    /* The decoders must be sure to never read beyond ilowest.
     * This is lower than iend[0], but allowing decoders to read
     * down to ilowest can allow an extra iteration or two in the
     * fast loop.
     */
    args->ilowest = istart;

    args->oend = oend;
    args->dt = dt;

    return 1;
}

static size_t HUF_initRemainingDStream(BIT_DStream_t* bit, HUF_DecompressFastArgs const* args, int stream, BYTE* segmentEnd)
{
    /* Validate that we haven't overwritten. */
    if (args->op[stream] > segmentEnd)
        return ERROR(corruption_detected);
    /* Validate that we haven't read beyond iend[].
        * Note that ip[] may be < iend[] because the MSB is
        * the next bit to read, and we may have consumed 100%
        * of the stream, so down to iend[i] - 8 is valid.
        */
    if (args->ip[stream] < args->iend[stream] - 8)
        return ERROR(corruption_detected);

    /* Construct the BIT_DStream_t. */
    assert(sizeof(size_t) == 8);
    bit->bitContainer = MEM_readLEST(args->ip[stream]);
    bit->bitsConsumed = ZSTD_countTrailingZeros64(args->bits[stream]);
    bit->start = (const char*)args->ilowest;
    bit->limitPtr = bit->start + sizeof(size_t);
    bit->ptr = (const char*)args->ip[stream];

    return 0;
}

/* Calls X(N) for each stream 0, 1, 2, 3. */
#define HUF_4X_FOR_EACH_STREAM(X) \
    do {                          \
        X(0);                     \
        X(1);                     \
        X(2);                     \
        X(3);                     \
    } while (0)

/* Calls X(N, var) for each stream 0, 1, 2, 3. */
#define HUF_4X_FOR_EACH_STREAM_WITH_VAR(X, var) \
    do {                                        \
        X(0, (var));                            \
        X(1, (var));                            \
        X(2, (var));                            \
        X(3, (var));                            \
    } while (0)


#ifndef HUF_FORCE_DECOMPRESS_X2

/*-***************************/
/*  single-symbol decoding   */
/*-***************************/
typedef struct { BYTE nbBits; BYTE byte; } HUF_DEltX1;   /* single-symbol decoding */

/**
 * Packs 4 HUF_DEltX1 structs into a U64. This is used to lay down 4 entries at
 * a time.
 */
static U64 HUF_DEltX1_set4(BYTE symbol, BYTE nbBits) {
    U64 D4;
    if (MEM_isLittleEndian()) {
        D4 = (U64)((symbol << 8) + nbBits);
    } else {
        D4 = (U64)(symbol + (nbBits << 8));
    }
    assert(D4 < (1U << 16));
    D4 *= 0x0001000100010001ULL;
    return D4;
}

/**
 * Increase the tableLog to targetTableLog and rescales the stats.
 * If tableLog > targetTableLog this is a no-op.
 * @returns New tableLog
 */
static U32 HUF_rescaleStats(BYTE* huffWeight, U32* rankVal, U32 nbSymbols, U32 tableLog, U32 targetTableLog)
{
    if (tableLog > targetTableLog)
        return tableLog;
    if (tableLog < targetTableLog) {
        U32 const scale = targetTableLog - tableLog;
        U32 s;
        /* Increase the weight for all non-zero probability symbols by scale. */
        for (s = 0; s < nbSymbols; ++s) {
            huffWeight[s] += (BYTE)((huffWeight[s] == 0) ? 0 : scale);
        }
        /* Update rankVal to reflect the new weights.
         * All weights except 0 get moved to weight + scale.
         * Weights [1, scale] are empty.
         */
        for (s = targetTableLog; s > scale; --s) {
            rankVal[s] = rankVal[s - scale];
        }
        for (s = scale; s > 0; --s) {
            rankVal[s] = 0;
        }
    }
    return targetTableLog;
}

typedef struct {
        U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1];
        U32 rankStart[HUF_TABLELOG_ABSOLUTEMAX + 1];
        U32 statsWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
        BYTE symbols[HUF_SYMBOLVALUE_MAX + 1];
        BYTE huffWeight[HUF_SYMBOLVALUE_MAX + 1];
} HUF_ReadDTableX1_Workspace;

size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags)
{
    U32 tableLog = 0;
    U32 nbSymbols = 0;
    size_t iSize;
    void* const dtPtr = DTable + 1;
    HUF_DEltX1* const dt = (HUF_DEltX1*)dtPtr;
    HUF_ReadDTableX1_Workspace* wksp = (HUF_ReadDTableX1_Workspace*)workSpace;

    DEBUG_STATIC_ASSERT(HUF_DECOMPRESS_WORKSPACE_SIZE >= sizeof(*wksp));
    if (sizeof(*wksp) > wkspSize) return ERROR(tableLog_tooLarge);

    DEBUG_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUF_DTable));
    /* ZSTD_memset(huffWeight, 0, sizeof(huffWeight)); */   /* is not necessary, even though some analyzer complain ... */

    iSize = HUF_readStats_wksp(wksp->huffWeight, HUF_SYMBOLVALUE_MAX + 1, wksp->rankVal, &nbSymbols, &tableLog, src, srcSize, wksp->statsWksp, sizeof(wksp->statsWksp), flags);
    if (HUF_isError(iSize)) return iSize;


    /* Table header */
    {   DTableDesc dtd = HUF_getDTableDesc(DTable);
        U32 const maxTableLog = dtd.maxTableLog + 1;
        U32 const targetTableLog = MIN(maxTableLog, HUF_DECODER_FAST_TABLELOG);
        tableLog = HUF_rescaleStats(wksp->huffWeight, wksp->rankVal, nbSymbols, tableLog, targetTableLog);
        if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge);   /* DTable too small, Huffman tree cannot fit in */
        dtd.tableType = 0;
        dtd.tableLog = (BYTE)tableLog;
        ZSTD_memcpy(DTable, &dtd, sizeof(dtd));
    }

    /* Compute symbols and rankStart given rankVal:
     *
     * rankVal already contains the number of values of each weight.
     *
     * symbols contains the symbols ordered by weight. First are the rankVal[0]
     * weight 0 symbols, followed by the rankVal[1] weight 1 symbols, and so on.
     * symbols[0] is filled (but unused) to avoid a branch.
     *
     * rankStart contains the offset where each rank belongs in the DTable.
     * rankStart[0] is not filled because there are no entries in the table for
     * weight 0.
     */
    {   int n;
        U32 nextRankStart = 0;
        int const unroll = 4;
        int const nLimit = (int)nbSymbols - unroll + 1;
        for (n=0; n<(int)tableLog+1; n++) {
            U32 const curr = nextRankStart;
            nextRankStart += wksp->rankVal[n];
            wksp->rankStart[n] = curr;
        }
        for (n=0; n < nLimit; n += unroll) {
            int u;
            for (u=0; u < unroll; ++u) {
                size_t const w = wksp->huffWeight[n+u];
                wksp->symbols[wksp->rankStart[w]++] = (BYTE)(n+u);
            }
        }
        for (; n < (int)nbSymbols; ++n) {
            size_t const w = wksp->huffWeight[n];
            wksp->symbols[wksp->rankStart[w]++] = (BYTE)n;
        }
    }

    /* fill DTable
     * We fill all entries of each weight in order.
     * That way length is a constant for each iteration of the outer loop.
     * We can switch based on the length to a different inner loop which is
     * optimized for that particular case.
     */
    {   U32 w;
        int symbol = wksp->rankVal[0];
        int rankStart = 0;
        for (w=1; w<tableLog+1; ++w) {
            int const symbolCount = wksp->rankVal[w];
            int const length = (1 << w) >> 1;
            int uStart = rankStart;
            BYTE const nbBits = (BYTE)(tableLog + 1 - w);
            int s;
            int u;
            switch (length) {
            case 1:
                for (s=0; s<symbolCount; ++s) {
                    HUF_DEltX1 D;
                    D.byte = wksp->symbols[symbol + s];
                    D.nbBits = nbBits;
                    dt[uStart] = D;
                    uStart += 1;
                }
                break;
            case 2:
                for (s=0; s<symbolCount; ++s) {
                    HUF_DEltX1 D;
                    D.byte = wksp->symbols[symbol + s];
                    D.nbBits = nbBits;
                    dt[uStart+0] = D;
                    dt[uStart+1] = D;
                    uStart += 2;
                }
                break;
            case 4:
                for (s=0; s<symbolCount; ++s) {
                    U64 const D4 = HUF_DEltX1_set4(wksp->symbols[symbol + s], nbBits);
                    MEM_write64(dt + uStart, D4);
                    uStart += 4;
                }
                break;
            case 8:
                for (s=0; s<symbolCount; ++s) {
                    U64 const D4 = HUF_DEltX1_set4(wksp->symbols[symbol + s], nbBits);
                    MEM_write64(dt + uStart, D4);
                    MEM_write64(dt + uStart + 4, D4);
                    uStart += 8;
                }
                break;
            default:
                for (s=0; s<symbolCount; ++s) {
                    U64 const D4 = HUF_DEltX1_set4(wksp->symbols[symbol + s], nbBits);
                    for (u=0; u < length; u += 16) {
                        MEM_write64(dt + uStart + u + 0, D4);
                        MEM_write64(dt + uStart + u + 4, D4);
                        MEM_write64(dt + uStart + u + 8, D4);
                        MEM_write64(dt + uStart + u + 12, D4);
                    }
                    assert(u == length);
                    uStart += length;
                }
                break;
            }
            symbol += symbolCount;
            rankStart += symbolCount * length;
        }
    }
    return iSize;
}

FORCE_INLINE_TEMPLATE BYTE
HUF_decodeSymbolX1(BIT_DStream_t* Dstream, const HUF_DEltX1* dt, const U32 dtLog)
{
    size_t const val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */
    BYTE const c = dt[val].byte;
    BIT_skipBits(Dstream, dt[val].nbBits);
    return c;
}

#define HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) \
    do { *ptr++ = HUF_decodeSymbolX1(DStreamPtr, dt, dtLog); } while (0)

#define HUF_DECODE_SYMBOLX1_1(ptr, DStreamPtr)      \
    do {                                            \
        if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \
            HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr); \
    } while (0)

#define HUF_DECODE_SYMBOLX1_2(ptr, DStreamPtr)      \
    do {                                            \
        if (MEM_64bits())                           \
            HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr); \
    } while (0)

HINT_INLINE size_t
HUF_decodeStreamX1(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX1* const dt, const U32 dtLog)
{
    BYTE* const pStart = p;

    /* up to 4 symbols at a time */
    if ((pEnd - p) > 3) {
        while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-3)) {
            HUF_DECODE_SYMBOLX1_2(p, bitDPtr);
            HUF_DECODE_SYMBOLX1_1(p, bitDPtr);
            HUF_DECODE_SYMBOLX1_2(p, bitDPtr);
            HUF_DECODE_SYMBOLX1_0(p, bitDPtr);
        }
    } else {
        BIT_reloadDStream(bitDPtr);
    }

    /* [0-3] symbols remaining */
    if (MEM_32bits())
        while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd))
            HUF_DECODE_SYMBOLX1_0(p, bitDPtr);

    /* no more data to retrieve from bitstream, no need to reload */
    while (p < pEnd)
        HUF_DECODE_SYMBOLX1_0(p, bitDPtr);

    return (size_t)(pEnd-pStart);
}

FORCE_INLINE_TEMPLATE size_t
HUF_decompress1X1_usingDTable_internal_body(
          void* dst,  size_t dstSize,
    const void* cSrc, size_t cSrcSize,
    const HUF_DTable* DTable)
{
    BYTE* op = (BYTE*)dst;
    BYTE* const oend = ZSTD_maybeNullPtrAdd(op, dstSize);
    const void* dtPtr = DTable + 1;
    const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;
    BIT_DStream_t bitD;
    DTableDesc const dtd = HUF_getDTableDesc(DTable);
    U32 const dtLog = dtd.tableLog;

    CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );

    HUF_decodeStreamX1(op, &bitD, oend, dt, dtLog);

    if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);

    return dstSize;
}

/* HUF_decompress4X1_usingDTable_internal_body():
 * Conditions :
 * @dstSize >= 6
 */
FORCE_INLINE_TEMPLATE size_t
HUF_decompress4X1_usingDTable_internal_body(
          void* dst,  size_t dstSize,
    const void* cSrc, size_t cSrcSize,
    const HUF_DTable* DTable)
{
    /* Check */
    if (cSrcSize < 10) return ERROR(corruption_detected);  /* strict minimum : jump table + 1 byte per stream */
    if (dstSize < 6) return ERROR(corruption_detected);         /* stream 4-split doesn't work */

    {   const BYTE* const istart = (const BYTE*) cSrc;
        BYTE* const ostart = (BYTE*) dst;
        BYTE* const oend = ostart + dstSize;
        BYTE* const olimit = oend - 3;
        const void* const dtPtr = DTable + 1;
        const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr;

        /* Init */
        BIT_DStream_t bitD1;
        BIT_DStream_t bitD2;
        BIT_DStream_t bitD3;
        BIT_DStream_t bitD4;
        size_t const length1 = MEM_readLE16(istart);
        size_t const length2 = MEM_readLE16(istart+2);
        size_t const length3 = MEM_readLE16(istart+4);
        size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
        const BYTE* const istart1 = istart + 6;  /* jumpTable */
        const BYTE* const istart2 = istart1 + length1;
        const BYTE* const istart3 = istart2 + length2;
        const BYTE* const istart4 = istart3 + length3;
        const size_t segmentSize = (dstSize+3) / 4;
        BYTE* const opStart2 = ostart + segmentSize;
        BYTE* const opStart3 = opStart2 + segmentSize;
        BYTE* const opStart4 = opStart3 + segmentSize;
        BYTE* op1 = ostart;
        BYTE* op2 = opStart2;
        BYTE* op3 = opStart3;
        BYTE* op4 = opStart4;
        DTableDesc const dtd = HUF_getDTableDesc(DTable);
        U32 const dtLog = dtd.tableLog;
        U32 endSignal = 1;

        if (length4 > cSrcSize) return ERROR(corruption_detected);   /* overflow */
        if (opStart4 > oend) return ERROR(corruption_detected);      /* overflow */
        assert(dstSize >= 6); /* validated above */
        CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
        CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
        CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
        CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );

        /* up to 16 symbols per loop (4 symbols per stream) in 64-bit mode */
        if ((size_t)(oend - op4) >= sizeof(size_t)) {
            for ( ; (endSignal) & (op4 < olimit) ; ) {
                HUF_DECODE_SYMBOLX1_2(op1, &bitD1);
                HUF_DECODE_SYMBOLX1_2(op2, &bitD2);
                HUF_DECODE_SYMBOLX1_2(op3, &bitD3);
                HUF_DECODE_SYMBOLX1_2(op4, &bitD4);
                HUF_DECODE_SYMBOLX1_1(op1, &bitD1);
                HUF_DECODE_SYMBOLX1_1(op2, &bitD2);
                HUF_DECODE_SYMBOLX1_1(op3, &bitD3);
                HUF_DECODE_SYMBOLX1_1(op4, &bitD4);
                HUF_DECODE_SYMBOLX1_2(op1, &bitD1);
                HUF_DECODE_SYMBOLX1_2(op2, &bitD2);
                HUF_DECODE_SYMBOLX1_2(op3, &bitD3);
                HUF_DECODE_SYMBOLX1_2(op4, &bitD4);
                HUF_DECODE_SYMBOLX1_0(op1, &bitD1);
                HUF_DECODE_SYMBOLX1_0(op2, &bitD2);
                HUF_DECODE_SYMBOLX1_0(op3, &bitD3);
                HUF_DECODE_SYMBOLX1_0(op4, &bitD4);
                endSignal &= BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished;
                endSignal &= BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished;
                endSignal &= BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished;
                endSignal &= BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished;
            }
        }

        /* check corruption */
        /* note : should not be necessary : op# advance in lock step, and we control op4.
         *        but curiously, binary generated by gcc 7.2 & 7.3 with -mbmi2 runs faster when >=1 test is present */
        if (op1 > opStart2) return ERROR(corruption_detected);
        if (op2 > opStart3) return ERROR(corruption_detected);
        if (op3 > opStart4) return ERROR(corruption_detected);
        /* note : op4 supposed already verified within main loop */

        /* finish bitStreams one by one */
        HUF_decodeStreamX1(op1, &bitD1, opStart2, dt, dtLog);
        HUF_decodeStreamX1(op2, &bitD2, opStart3, dt, dtLog);
        HUF_decodeStreamX1(op3, &bitD3, opStart4, dt, dtLog);
        HUF_decodeStreamX1(op4, &bitD4, oend,     dt, dtLog);

        /* check */
        { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
          if (!endCheck) return ERROR(corruption_detected); }

        /* decoded size */
        return dstSize;
    }
}

#if HUF_NEED_BMI2_FUNCTION
static BMI2_TARGET_ATTRIBUTE
size_t HUF_decompress4X1_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc,
                    size_t cSrcSize, HUF_DTable const* DTable) {
    return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}
#endif

static
size_t HUF_decompress4X1_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc,
                    size_t cSrcSize, HUF_DTable const* DTable) {
    return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}

#if ZSTD_ENABLE_ASM_X86_64_BMI2

HUF_ASM_DECL void HUF_decompress4X1_usingDTable_internal_fast_asm_loop(HUF_DecompressFastArgs* args) ZSTDLIB_HIDDEN;

#endif

static HUF_FAST_BMI2_ATTRS
void HUF_decompress4X1_usingDTable_internal_fast_c_loop(HUF_DecompressFastArgs* args)
{
    U64 bits[4];
    BYTE const* ip[4];
    BYTE* op[4];
    U16 const* const dtable = (U16 const*)args->dt;
    BYTE* const oend = args->oend;
    BYTE const* const ilowest = args->ilowest;

    /* Copy the arguments to local variables */
    ZSTD_memcpy(&bits, &args->bits, sizeof(bits));
    ZSTD_memcpy((void*)(&ip), &args->ip, sizeof(ip));
    ZSTD_memcpy(&op, &args->op, sizeof(op));

    assert(MEM_isLittleEndian());
    assert(!MEM_32bits());

    for (;;) {
        BYTE* olimit;
        int stream;

        /* Assert loop preconditions */
#ifndef NDEBUG
        for (stream = 0; stream < 4; ++stream) {
            assert(op[stream] <= (stream == 3 ? oend : op[stream + 1]));
            assert(ip[stream] >= ilowest);
        }
#endif
        /* Compute olimit */
        {
            /* Each iteration produces 5 output symbols per stream */
            size_t const oiters = (size_t)(oend - op[3]) / 5;
            /* Each iteration consumes up to 11 bits * 5 = 55 bits < 7 bytes
             * per stream.
             */
            size_t const iiters = (size_t)(ip[0] - ilowest) / 7;
            /* We can safely run iters iterations before running bounds checks */
            size_t const iters = MIN(oiters, iiters);
            size_t const symbols = iters * 5;

            /* We can simply check that op[3] < olimit, instead of checking all
             * of our bounds, since we can't hit the other bounds until we've run
             * iters iterations, which only happens when op[3] == olimit.
             */
            olimit = op[3] + symbols;

            /* Exit fast decoding loop once we reach the end. */
            if (op[3] == olimit)
                break;

            /* Exit the decoding loop if any input pointer has crossed the
             * previous one. This indicates corruption, and a precondition
             * to our loop is that ip[i] >= ip[0].
             */
            for (stream = 1; stream < 4; ++stream) {
                if (ip[stream] < ip[stream - 1])
                    goto _out;
            }
        }

#ifndef NDEBUG
        for (stream = 1; stream < 4; ++stream) {
            assert(ip[stream] >= ip[stream - 1]);
        }
#endif

#define HUF_4X1_DECODE_SYMBOL(_stream, _symbol)                 \
    do {                                                        \
        int const index = (int)(bits[(_stream)] >> 53);         \
        int const entry = (int)dtable[index];                   \
        bits[(_stream)] <<= (entry & 0x3F);                     \
        op[(_stream)][(_symbol)] = (BYTE)((entry >> 8) & 0xFF); \
    } while (0)

#define HUF_4X1_RELOAD_STREAM(_stream)                              \
    do {                                                            \
        int const ctz = ZSTD_countTrailingZeros64(bits[(_stream)]); \
        int const nbBits = ctz & 7;                                 \
        int const nbBytes = ctz >> 3;                               \
        op[(_stream)] += 5;                                         \
        ip[(_stream)] -= nbBytes;                                   \
        bits[(_stream)] = MEM_read64(ip[(_stream)]) | 1;            \
        bits[(_stream)] <<= nbBits;                                 \
    } while (0)

        /* Manually unroll the loop because compilers don't consistently
         * unroll the inner loops, which destroys performance.
         */
        do {
            /* Decode 5 symbols in each of the 4 streams */
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 0);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 1);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 2);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 3);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X1_DECODE_SYMBOL, 4);

            /* Reload each of the 4 the bitstreams */
            HUF_4X_FOR_EACH_STREAM(HUF_4X1_RELOAD_STREAM);
        } while (op[3] < olimit);

#undef HUF_4X1_DECODE_SYMBOL
#undef HUF_4X1_RELOAD_STREAM
    }

_out:

    /* Save the final values of each of the state variables back to args. */
    ZSTD_memcpy(&args->bits, &bits, sizeof(bits));
    ZSTD_memcpy((void*)(&args->ip), &ip, sizeof(ip));
    ZSTD_memcpy(&args->op, &op, sizeof(op));
}

/**
 * @returns @p dstSize on success (>= 6)
 *          0 if the fallback implementation should be used
 *          An error if an error occurred
 */
static HUF_FAST_BMI2_ATTRS
size_t
HUF_decompress4X1_usingDTable_internal_fast(
          void* dst,  size_t dstSize,
    const void* cSrc, size_t cSrcSize,
    const HUF_DTable* DTable,
    HUF_DecompressFastLoopFn loopFn)
{
    void const* dt = DTable + 1;
    BYTE const* const ilowest = (BYTE const*)cSrc;
    BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize);
    HUF_DecompressFastArgs args;
    {   size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable);
        FORWARD_IF_ERROR(ret, "Failed to init fast loop args");
        if (ret == 0)
            return 0;
    }

    assert(args.ip[0] >= args.ilowest);
    loopFn(&args);

    /* Our loop guarantees that ip[] >= ilowest and that we haven't
    * overwritten any op[].
    */
    assert(args.ip[0] >= ilowest);
    assert(args.ip[0] >= ilowest);
    assert(args.ip[1] >= ilowest);
    assert(args.ip[2] >= ilowest);
    assert(args.ip[3] >= ilowest);
    assert(args.op[3] <= oend);

    assert(ilowest == args.ilowest);
    assert(ilowest + 6 == args.iend[0]);
    (void)ilowest;

    /* finish bit streams one by one. */
    {   size_t const segmentSize = (dstSize+3) / 4;
        BYTE* segmentEnd = (BYTE*)dst;
        int i;
        for (i = 0; i < 4; ++i) {
            BIT_DStream_t bit;
            if (segmentSize <= (size_t)(oend - segmentEnd))
                segmentEnd += segmentSize;
            else
                segmentEnd = oend;
            FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption");
            /* Decompress and validate that we've produced exactly the expected length. */
            args.op[i] += HUF_decodeStreamX1(args.op[i], &bit, segmentEnd, (HUF_DEltX1 const*)dt, HUF_DECODER_FAST_TABLELOG);
            if (args.op[i] != segmentEnd) return ERROR(corruption_detected);
        }
    }

    /* decoded size */
    assert(dstSize != 0);
    return dstSize;
}

HUF_DGEN(HUF_decompress1X1_usingDTable_internal)

static size_t HUF_decompress4X1_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc,
                    size_t cSrcSize, HUF_DTable const* DTable, int flags)
{
    HUF_DecompressUsingDTableFn fallbackFn = HUF_decompress4X1_usingDTable_internal_default;
    HUF_DecompressFastLoopFn loopFn = HUF_decompress4X1_usingDTable_internal_fast_c_loop;

#if DYNAMIC_BMI2
    if (flags & HUF_flags_bmi2) {
        fallbackFn = HUF_decompress4X1_usingDTable_internal_bmi2;
# if ZSTD_ENABLE_ASM_X86_64_BMI2
        if (!(flags & HUF_flags_disableAsm)) {
            loopFn = HUF_decompress4X1_usingDTable_internal_fast_asm_loop;
        }
# endif
    } else {
        return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable);
    }
#endif

#if ZSTD_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__)
    if (!(flags & HUF_flags_disableAsm)) {
        loopFn = HUF_decompress4X1_usingDTable_internal_fast_asm_loop;
    }
#endif

    if (HUF_ENABLE_FAST_DECODE && !(flags & HUF_flags_disableFast)) {
        size_t const ret = HUF_decompress4X1_usingDTable_internal_fast(dst, dstSize, cSrc, cSrcSize, DTable, loopFn);
        if (ret != 0)
            return ret;
    }
    return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable);
}

static size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                   const void* cSrc, size_t cSrcSize,
                                   void* workSpace, size_t wkspSize, int flags)
{
    const BYTE* ip = (const BYTE*) cSrc;

    size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags);
    if (HUF_isError(hSize)) return hSize;
    if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
    ip += hSize; cSrcSize -= hSize;

    return HUF_decompress4X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags);
}

#endif /* HUF_FORCE_DECOMPRESS_X2 */


#ifndef HUF_FORCE_DECOMPRESS_X1

/* *************************/
/* double-symbols decoding */
/* *************************/

typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX2;  /* double-symbols decoding */
typedef struct { BYTE symbol; } sortedSymbol_t;
typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1];
typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX];

/**
 * Constructs a HUF_DEltX2 in a U32.
 */
static U32 HUF_buildDEltX2U32(U32 symbol, U32 nbBits, U32 baseSeq, int level)
{
    U32 seq;
    DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, sequence) == 0);
    DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, nbBits) == 2);
    DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, length) == 3);
    DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U32));
    if (MEM_isLittleEndian()) {
        seq = level == 1 ? symbol : (baseSeq + (symbol << 8));
        return seq + (nbBits << 16) + ((U32)level << 24);
    } else {
        seq = level == 1 ? (symbol << 8) : ((baseSeq << 8) + symbol);
        return (seq << 16) + (nbBits << 8) + (U32)level;
    }
}

/**
 * Constructs a HUF_DEltX2.
 */
static HUF_DEltX2 HUF_buildDEltX2(U32 symbol, U32 nbBits, U32 baseSeq, int level)
{
    HUF_DEltX2 DElt;
    U32 const val = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level);
    DEBUG_STATIC_ASSERT(sizeof(DElt) == sizeof(val));
    ZSTD_memcpy(&DElt, &val, sizeof(val));
    return DElt;
}

/**
 * Constructs 2 HUF_DEltX2s and packs them into a U64.
 */
static U64 HUF_buildDEltX2U64(U32 symbol, U32 nbBits, U16 baseSeq, int level)
{
    U32 DElt = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level);
    return (U64)DElt + ((U64)DElt << 32);
}

/**
 * Fills the DTable rank with all the symbols from [begin, end) that are each
 * nbBits long.
 *
 * @param DTableRank The start of the rank in the DTable.
 * @param begin The first symbol to fill (inclusive).
 * @param end The last symbol to fill (exclusive).
 * @param nbBits Each symbol is nbBits long.
 * @param tableLog The table log.
 * @param baseSeq If level == 1 { 0 } else { the first level symbol }
 * @param level The level in the table. Must be 1 or 2.
 */
static void HUF_fillDTableX2ForWeight(
    HUF_DEltX2* DTableRank,
    sortedSymbol_t const* begin, sortedSymbol_t const* end,
    U32 nbBits, U32 tableLog,
    U16 baseSeq, int const level)
{
    U32 const length = 1U << ((tableLog - nbBits) & 0x1F /* quiet static-analyzer */);
    const sortedSymbol_t* ptr;
    assert(level >= 1 && level <= 2);
    switch (length) {
    case 1:
        for (ptr = begin; ptr != end; ++ptr) {
            HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level);
            *DTableRank++ = DElt;
        }
        break;
    case 2:
        for (ptr = begin; ptr != end; ++ptr) {
            HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level);
            DTableRank[0] = DElt;
            DTableRank[1] = DElt;
            DTableRank += 2;
        }
        break;
    case 4:
        for (ptr = begin; ptr != end; ++ptr) {
            U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level);
            ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2));
            ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2));
            DTableRank += 4;
        }
        break;
    case 8:
        for (ptr = begin; ptr != end; ++ptr) {
            U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level);
            ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2));
            ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2));
            ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2));
            ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2));
            DTableRank += 8;
        }
        break;
    default:
        for (ptr = begin; ptr != end; ++ptr) {
            U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level);
            HUF_DEltX2* const DTableRankEnd = DTableRank + length;
            for (; DTableRank != DTableRankEnd; DTableRank += 8) {
                ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2));
                ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2));
                ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2));
                ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2));
            }
        }
        break;
    }
}

/* HUF_fillDTableX2Level2() :
 * `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */
static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 targetLog, const U32 consumedBits,
                           const U32* rankVal, const int minWeight, const int maxWeight1,
                           const sortedSymbol_t* sortedSymbols, U32 const* rankStart,
                           U32 nbBitsBaseline, U16 baseSeq)
{
    /* Fill skipped values (all positions up to rankVal[minWeight]).
     * These are positions only get a single symbol because the combined weight
     * is too large.
     */
    if (minWeight>1) {
        U32 const length = 1U << ((targetLog - consumedBits) & 0x1F /* quiet static-analyzer */);
        U64 const DEltX2 = HUF_buildDEltX2U64(baseSeq, consumedBits, /* baseSeq */ 0, /* level */ 1);
        int const skipSize = rankVal[minWeight];
        assert(length > 1);
        assert((U32)skipSize < length);
        switch (length) {
        case 2:
            assert(skipSize == 1);
            ZSTD_memcpy(DTable, &DEltX2, sizeof(DEltX2));
            break;
        case 4:
            assert(skipSize <= 4);
            ZSTD_memcpy(DTable + 0, &DEltX2, sizeof(DEltX2));
            ZSTD_memcpy(DTable + 2, &DEltX2, sizeof(DEltX2));
            break;
        default:
            {
                int i;
                for (i = 0; i < skipSize; i += 8) {
                    ZSTD_memcpy(DTable + i + 0, &DEltX2, sizeof(DEltX2));
                    ZSTD_memcpy(DTable + i + 2, &DEltX2, sizeof(DEltX2));
                    ZSTD_memcpy(DTable + i + 4, &DEltX2, sizeof(DEltX2));
                    ZSTD_memcpy(DTable + i + 6, &DEltX2, sizeof(DEltX2));
                }
            }
        }
    }

    /* Fill each of the second level symbols by weight. */
    {
        int w;
        for (w = minWeight; w < maxWeight1; ++w) {
            int const begin = rankStart[w];
            int const end = rankStart[w+1];
            U32 const nbBits = nbBitsBaseline - w;
            U32 const totalBits = nbBits + consumedBits;
            HUF_fillDTableX2ForWeight(
                DTable + rankVal[w],
                sortedSymbols + begin, sortedSymbols + end,
                totalBits, targetLog,
                baseSeq, /* level */ 2);
        }
    }
}

static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
                           const sortedSymbol_t* sortedList,
                           const U32* rankStart, rankValCol_t* rankValOrigin, const U32 maxWeight,
                           const U32 nbBitsBaseline)
{
    U32* const rankVal = rankValOrigin[0];
    const int scaleLog = nbBitsBaseline - targetLog;   /* note : targetLog >= srcLog, hence scaleLog <= 1 */
    const U32 minBits  = nbBitsBaseline - maxWeight;
    int w;
    int const wEnd = (int)maxWeight + 1;

    /* Fill DTable in order of weight. */
    for (w = 1; w < wEnd; ++w) {
        int const begin = (int)rankStart[w];
        int const end = (int)rankStart[w+1];
        U32 const nbBits = nbBitsBaseline - w;

        if (targetLog-nbBits >= minBits) {
            /* Enough room for a second symbol. */
            int start = rankVal[w];
            U32 const length = 1U << ((targetLog - nbBits) & 0x1F /* quiet static-analyzer */);
            int minWeight = nbBits + scaleLog;
            int s;
            if (minWeight < 1) minWeight = 1;
            /* Fill the DTable for every symbol of weight w.
             * These symbols get at least 1 second symbol.
             */
            for (s = begin; s != end; ++s) {
                HUF_fillDTableX2Level2(
                    DTable + start, targetLog, nbBits,
                    rankValOrigin[nbBits], minWeight, wEnd,
                    sortedList, rankStart,
                    nbBitsBaseline, sortedList[s].symbol);
                start += length;
            }
        } else {
            /* Only a single symbol. */
            HUF_fillDTableX2ForWeight(
                DTable + rankVal[w],
                sortedList + begin, sortedList + end,
                nbBits, targetLog,
                /* baseSeq */ 0, /* level */ 1);
        }
    }
}

typedef struct {
    rankValCol_t rankVal[HUF_TABLELOG_MAX];
    U32 rankStats[HUF_TABLELOG_MAX + 1];
    U32 rankStart0[HUF_TABLELOG_MAX + 3];
    sortedSymbol_t sortedSymbol[HUF_SYMBOLVALUE_MAX + 1];
    BYTE weightList[HUF_SYMBOLVALUE_MAX + 1];
    U32 calleeWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
} HUF_ReadDTableX2_Workspace;

size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
                       const void* src, size_t srcSize,
                             void* workSpace, size_t wkspSize, int flags)
{
    U32 tableLog, maxW, nbSymbols;
    DTableDesc dtd = HUF_getDTableDesc(DTable);
    U32 maxTableLog = dtd.maxTableLog;
    size_t iSize;
    void* dtPtr = DTable+1;   /* force compiler to avoid strict-aliasing */
    HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
    U32 *rankStart;

    HUF_ReadDTableX2_Workspace* const wksp = (HUF_ReadDTableX2_Workspace*)workSpace;

    if (sizeof(*wksp) > wkspSize) return ERROR(GENERIC);

    rankStart = wksp->rankStart0 + 1;
    ZSTD_memset(wksp->rankStats, 0, sizeof(wksp->rankStats));
    ZSTD_memset(wksp->rankStart0, 0, sizeof(wksp->rankStart0));

    DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(HUF_DTable));   /* if compiler fails here, assertion is wrong */
    if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
    /* ZSTD_memset(weightList, 0, sizeof(weightList)); */  /* is not necessary, even though some analyzer complain ... */

    iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), flags);
    if (HUF_isError(iSize)) return iSize;

    /* check result */
    if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge);   /* DTable can't fit code depth */
    if (tableLog <= HUF_DECODER_FAST_TABLELOG && maxTableLog > HUF_DECODER_FAST_TABLELOG) maxTableLog = HUF_DECODER_FAST_TABLELOG;

    /* find maxWeight */
    for (maxW = tableLog; wksp->rankStats[maxW]==0; maxW--) {}  /* necessarily finds a solution before 0 */

    /* Get start index of each weight */
    {   U32 w, nextRankStart = 0;
        for (w=1; w<maxW+1; w++) {
            U32 curr = nextRankStart;
            nextRankStart += wksp->rankStats[w];
            rankStart[w] = curr;
        }
        rankStart[0] = nextRankStart;   /* put all 0w symbols at the end of sorted list*/
        rankStart[maxW+1] = nextRankStart;
    }

    /* sort symbols by weight */
    {   U32 s;
        for (s=0; s<nbSymbols; s++) {
            U32 const w = wksp->weightList[s];
            U32 const r = rankStart[w]++;
            wksp->sortedSymbol[r].symbol = (BYTE)s;
        }
        rankStart[0] = 0;   /* forget 0w symbols; this is beginning of weight(1) */
    }

    /* Build rankVal */
    {   U32* const rankVal0 = wksp->rankVal[0];
        {   int const rescale = (maxTableLog-tableLog) - 1;   /* tableLog <= maxTableLog */
            U32 nextRankVal = 0;
            U32 w;
            for (w=1; w<maxW+1; w++) {
                U32 curr = nextRankVal;
                nextRankVal += wksp->rankStats[w] << (w+rescale);
                rankVal0[w] = curr;
        }   }
        {   U32 const minBits = tableLog+1 - maxW;
            U32 consumed;
            for (consumed = minBits; consumed < maxTableLog - minBits + 1; consumed++) {
                U32* const rankValPtr = wksp->rankVal[consumed];
                U32 w;
                for (w = 1; w < maxW+1; w++) {
                    rankValPtr[w] = rankVal0[w] >> consumed;
    }   }   }   }

    HUF_fillDTableX2(dt, maxTableLog,
                   wksp->sortedSymbol,
                   wksp->rankStart0, wksp->rankVal, maxW,
                   tableLog+1);

    dtd.tableLog = (BYTE)maxTableLog;
    dtd.tableType = 1;
    ZSTD_memcpy(DTable, &dtd, sizeof(dtd));
    return iSize;
}


FORCE_INLINE_TEMPLATE U32
HUF_decodeSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
{
    size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
    ZSTD_memcpy(op, &dt[val].sequence, 2);
    BIT_skipBits(DStream, dt[val].nbBits);
    return dt[val].length;
}

FORCE_INLINE_TEMPLATE U32
HUF_decodeLastSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
{
    size_t const val = BIT_lookBitsFast(DStream, dtLog);   /* note : dtLog >= 1 */
    ZSTD_memcpy(op, &dt[val].sequence, 1);
    if (dt[val].length==1) {
        BIT_skipBits(DStream, dt[val].nbBits);
    } else {
        if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) {
            BIT_skipBits(DStream, dt[val].nbBits);
            if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
                /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
                DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);
        }
    }
    return 1;
}

#define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \
    do { ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog); } while (0)

#define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr)                     \
    do {                                                           \
        if (MEM_64bits() || (HUF_TABLELOG_MAX<=12))                \
            ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog); \
    } while (0)

#define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr)                     \
    do {                                                           \
        if (MEM_64bits())                                          \
            ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog); \
    } while (0)

HINT_INLINE size_t
HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd,
                const HUF_DEltX2* const dt, const U32 dtLog)
{
    BYTE* const pStart = p;

    /* up to 8 symbols at a time */
    if ((size_t)(pEnd - p) >= sizeof(bitDPtr->bitContainer)) {
        if (dtLog <= 11 && MEM_64bits()) {
            /* up to 10 symbols at a time */
            while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-9)) {
                HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
            }
        } else {
            /* up to 8 symbols at a time */
            while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) {
                HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
                HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
            }
        }
    } else {
        BIT_reloadDStream(bitDPtr);
    }

    /* closer to end : up to 2 symbols at a time */
    if ((size_t)(pEnd - p) >= 2) {
        while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p <= pEnd-2))
            HUF_DECODE_SYMBOLX2_0(p, bitDPtr);

        while (p <= pEnd-2)
            HUF_DECODE_SYMBOLX2_0(p, bitDPtr);   /* no need to reload : reached the end of DStream */
    }

    if (p < pEnd)
        p += HUF_decodeLastSymbolX2(p, bitDPtr, dt, dtLog);

    return p-pStart;
}

FORCE_INLINE_TEMPLATE size_t
HUF_decompress1X2_usingDTable_internal_body(
          void* dst,  size_t dstSize,
    const void* cSrc, size_t cSrcSize,
    const HUF_DTable* DTable)
{
    BIT_DStream_t bitD;

    /* Init */
    CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) );

    /* decode */
    {   BYTE* const ostart = (BYTE*) dst;
        BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, dstSize);
        const void* const dtPtr = DTable+1;   /* force compiler to not use strict-aliasing */
        const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;
        DTableDesc const dtd = HUF_getDTableDesc(DTable);
        HUF_decodeStreamX2(ostart, &bitD, oend, dt, dtd.tableLog);
    }

    /* check */
    if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected);

    /* decoded size */
    return dstSize;
}

/* HUF_decompress4X2_usingDTable_internal_body():
 * Conditions:
 * @dstSize >= 6
 */
FORCE_INLINE_TEMPLATE size_t
HUF_decompress4X2_usingDTable_internal_body(
          void* dst,  size_t dstSize,
    const void* cSrc, size_t cSrcSize,
    const HUF_DTable* DTable)
{
    if (cSrcSize < 10) return ERROR(corruption_detected);   /* strict minimum : jump table + 1 byte per stream */
    if (dstSize < 6) return ERROR(corruption_detected);         /* stream 4-split doesn't work */

    {   const BYTE* const istart = (const BYTE*) cSrc;
        BYTE* const ostart = (BYTE*) dst;
        BYTE* const oend = ostart + dstSize;
        BYTE* const olimit = oend - (sizeof(size_t)-1);
        const void* const dtPtr = DTable+1;
        const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr;

        /* Init */
        BIT_DStream_t bitD1;
        BIT_DStream_t bitD2;
        BIT_DStream_t bitD3;
        BIT_DStream_t bitD4;
        size_t const length1 = MEM_readLE16(istart);
        size_t const length2 = MEM_readLE16(istart+2);
        size_t const length3 = MEM_readLE16(istart+4);
        size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6);
        const BYTE* const istart1 = istart + 6;  /* jumpTable */
        const BYTE* const istart2 = istart1 + length1;
        const BYTE* const istart3 = istart2 + length2;
        const BYTE* const istart4 = istart3 + length3;
        size_t const segmentSize = (dstSize+3) / 4;
        BYTE* const opStart2 = ostart + segmentSize;
        BYTE* const opStart3 = opStart2 + segmentSize;
        BYTE* const opStart4 = opStart3 + segmentSize;
        BYTE* op1 = ostart;
        BYTE* op2 = opStart2;
        BYTE* op3 = opStart3;
        BYTE* op4 = opStart4;
        U32 endSignal = 1;
        DTableDesc const dtd = HUF_getDTableDesc(DTable);
        U32 const dtLog = dtd.tableLog;

        if (length4 > cSrcSize) return ERROR(corruption_detected);  /* overflow */
        if (opStart4 > oend) return ERROR(corruption_detected);     /* overflow */
        assert(dstSize >= 6 /* validated above */);
        CHECK_F( BIT_initDStream(&bitD1, istart1, length1) );
        CHECK_F( BIT_initDStream(&bitD2, istart2, length2) );
        CHECK_F( BIT_initDStream(&bitD3, istart3, length3) );
        CHECK_F( BIT_initDStream(&bitD4, istart4, length4) );

        /* 16-32 symbols per loop (4-8 symbols per stream) */
        if ((size_t)(oend - op4) >= sizeof(size_t)) {
            for ( ; (endSignal) & (op4 < olimit); ) {
#if defined(__clang__) && (defined(__x86_64__) || defined(__i386__))
                HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
                endSignal &= BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished;
                endSignal &= BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished;
                HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
                HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
                HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
                HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
                endSignal &= BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished;
                endSignal &= BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished;
#else
                HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
                HUF_DECODE_SYMBOLX2_1(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_1(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_1(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_1(op4, &bitD4);
                HUF_DECODE_SYMBOLX2_2(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_2(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_2(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_2(op4, &bitD4);
                HUF_DECODE_SYMBOLX2_0(op1, &bitD1);
                HUF_DECODE_SYMBOLX2_0(op2, &bitD2);
                HUF_DECODE_SYMBOLX2_0(op3, &bitD3);
                HUF_DECODE_SYMBOLX2_0(op4, &bitD4);
                endSignal = (U32)LIKELY((U32)
                            (BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished)
                        & (BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished)
                        & (BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished)
                        & (BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished));
#endif
            }
        }

        /* check corruption */
        if (op1 > opStart2) return ERROR(corruption_detected);
        if (op2 > opStart3) return ERROR(corruption_detected);
        if (op3 > opStart4) return ERROR(corruption_detected);
        /* note : op4 already verified within main loop */

        /* finish bitStreams one by one */
        HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog);
        HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog);
        HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog);
        HUF_decodeStreamX2(op4, &bitD4, oend,     dt, dtLog);

        /* check */
        { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4);
          if (!endCheck) return ERROR(corruption_detected); }

        /* decoded size */
        return dstSize;
    }
}

#if HUF_NEED_BMI2_FUNCTION
static BMI2_TARGET_ATTRIBUTE
size_t HUF_decompress4X2_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc,
                    size_t cSrcSize, HUF_DTable const* DTable) {
    return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}
#endif

static
size_t HUF_decompress4X2_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc,
                    size_t cSrcSize, HUF_DTable const* DTable) {
    return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}

#if ZSTD_ENABLE_ASM_X86_64_BMI2

HUF_ASM_DECL void HUF_decompress4X2_usingDTable_internal_fast_asm_loop(HUF_DecompressFastArgs* args) ZSTDLIB_HIDDEN;

#endif

static HUF_FAST_BMI2_ATTRS
void HUF_decompress4X2_usingDTable_internal_fast_c_loop(HUF_DecompressFastArgs* args)
{
    U64 bits[4];
    BYTE const* ip[4];
    BYTE* op[4];
    BYTE* oend[4];
    HUF_DEltX2 const* const dtable = (HUF_DEltX2 const*)args->dt;
    BYTE const* const ilowest = args->ilowest;

    /* Copy the arguments to local registers. */
    ZSTD_memcpy(&bits, &args->bits, sizeof(bits));
    ZSTD_memcpy((void*)(&ip), &args->ip, sizeof(ip));
    ZSTD_memcpy(&op, &args->op, sizeof(op));

    oend[0] = op[1];
    oend[1] = op[2];
    oend[2] = op[3];
    oend[3] = args->oend;

    assert(MEM_isLittleEndian());
    assert(!MEM_32bits());

    for (;;) {
        BYTE* olimit;
        int stream;

        /* Assert loop preconditions */
#ifndef NDEBUG
        for (stream = 0; stream < 4; ++stream) {
            assert(op[stream] <= oend[stream]);
            assert(ip[stream] >= ilowest);
        }
#endif
        /* Compute olimit */
        {
            /* Each loop does 5 table lookups for each of the 4 streams.
             * Each table lookup consumes up to 11 bits of input, and produces
             * up to 2 bytes of output.
             */
            /* We can consume up to 7 bytes of input per iteration per stream.
             * We also know that each input pointer is >= ip[0]. So we can run
             * iters loops before running out of input.
             */
            size_t iters = (size_t)(ip[0] - ilowest) / 7;
            /* Each iteration can produce up to 10 bytes of output per stream.
             * Each output stream my advance at different rates. So take the
             * minimum number of safe iterations among all the output streams.
             */
            for (stream = 0; stream < 4; ++stream) {
                size_t const oiters = (size_t)(oend[stream] - op[stream]) / 10;
                iters = MIN(iters, oiters);
            }

            /* Each iteration produces at least 5 output symbols. So until
             * op[3] crosses olimit, we know we haven't executed iters
             * iterations yet. This saves us maintaining an iters counter,
             * at the expense of computing the remaining # of iterations
             * more frequently.
             */
            olimit = op[3] + (iters * 5);

            /* Exit the fast decoding loop once we reach the end. */
            if (op[3] == olimit)
                break;

            /* Exit the decoding loop if any input pointer has crossed the
             * previous one. This indicates corruption, and a precondition
             * to our loop is that ip[i] >= ip[0].
             */
            for (stream = 1; stream < 4; ++stream) {
                if (ip[stream] < ip[stream - 1])
                    goto _out;
            }
        }

#ifndef NDEBUG
        for (stream = 1; stream < 4; ++stream) {
            assert(ip[stream] >= ip[stream - 1]);
        }
#endif

#define HUF_4X2_DECODE_SYMBOL(_stream, _decode3)                      \
    do {                                                              \
        if ((_decode3) || (_stream) != 3) {                           \
            int const index = (int)(bits[(_stream)] >> 53);           \
            HUF_DEltX2 const entry = dtable[index];                   \
            MEM_write16(op[(_stream)], entry.sequence); \
            bits[(_stream)] <<= (entry.nbBits) & 0x3F;                \
            op[(_stream)] += (entry.length);                          \
        }                                                             \
    } while (0)

#define HUF_4X2_RELOAD_STREAM(_stream)                                  \
    do {                                                                \
        HUF_4X2_DECODE_SYMBOL(3, 1);                                    \
        {                                                               \
            int const ctz = ZSTD_countTrailingZeros64(bits[(_stream)]); \
            int const nbBits = ctz & 7;                                 \
            int const nbBytes = ctz >> 3;                               \
            ip[(_stream)] -= nbBytes;                                   \
            bits[(_stream)] = MEM_read64(ip[(_stream)]) | 1;            \
            bits[(_stream)] <<= nbBits;                                 \
        }                                                               \
    } while (0)

        /* Manually unroll the loop because compilers don't consistently
         * unroll the inner loops, which destroys performance.
         */
        do {
            /* Decode 5 symbols from each of the first 3 streams.
             * The final stream will be decoded during the reload phase
             * to reduce register pressure.
             */
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0);
            HUF_4X_FOR_EACH_STREAM_WITH_VAR(HUF_4X2_DECODE_SYMBOL, 0);

            /* Decode one symbol from the final stream */
            HUF_4X2_DECODE_SYMBOL(3, 1);

            /* Decode 4 symbols from the final stream & reload bitstreams.
             * The final stream is reloaded last, meaning that all 5 symbols
             * are decoded from the final stream before it is reloaded.
             */
            HUF_4X_FOR_EACH_STREAM(HUF_4X2_RELOAD_STREAM);
        } while (op[3] < olimit);
    }

#undef HUF_4X2_DECODE_SYMBOL
#undef HUF_4X2_RELOAD_STREAM

_out:

    /* Save the final values of each of the state variables back to args. */
    ZSTD_memcpy(&args->bits, &bits, sizeof(bits));
    ZSTD_memcpy((void*)(&args->ip), &ip, sizeof(ip));
    ZSTD_memcpy(&args->op, &op, sizeof(op));
}


static HUF_FAST_BMI2_ATTRS size_t
HUF_decompress4X2_usingDTable_internal_fast(
          void* dst,  size_t dstSize,
    const void* cSrc, size_t cSrcSize,
    const HUF_DTable* DTable,
    HUF_DecompressFastLoopFn loopFn) {
    void const* dt = DTable + 1;
    const BYTE* const ilowest = (const BYTE*)cSrc;
    BYTE* const oend = ZSTD_maybeNullPtrAdd((BYTE*)dst, dstSize);
    HUF_DecompressFastArgs args;
    {
        size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable);
        FORWARD_IF_ERROR(ret, "Failed to init asm args");
        if (ret == 0)
            return 0;
    }

    assert(args.ip[0] >= args.ilowest);
    loopFn(&args);

    /* note : op4 already verified within main loop */
    assert(args.ip[0] >= ilowest);
    assert(args.ip[1] >= ilowest);
    assert(args.ip[2] >= ilowest);
    assert(args.ip[3] >= ilowest);
    assert(args.op[3] <= oend);

    assert(ilowest == args.ilowest);
    assert(ilowest + 6 == args.iend[0]);
    (void)ilowest;

    /* finish bitStreams one by one */
    {
        size_t const segmentSize = (dstSize+3) / 4;
        BYTE* segmentEnd = (BYTE*)dst;
        int i;
        for (i = 0; i < 4; ++i) {
            BIT_DStream_t bit;
            if (segmentSize <= (size_t)(oend - segmentEnd))
                segmentEnd += segmentSize;
            else
                segmentEnd = oend;
            FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption");
            args.op[i] += HUF_decodeStreamX2(args.op[i], &bit, segmentEnd, (HUF_DEltX2 const*)dt, HUF_DECODER_FAST_TABLELOG);
            if (args.op[i] != segmentEnd)
                return ERROR(corruption_detected);
        }
    }

    /* decoded size */
    return dstSize;
}

static size_t HUF_decompress4X2_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc,
                    size_t cSrcSize, HUF_DTable const* DTable, int flags)
{
    HUF_DecompressUsingDTableFn fallbackFn = HUF_decompress4X2_usingDTable_internal_default;
    HUF_DecompressFastLoopFn loopFn = HUF_decompress4X2_usingDTable_internal_fast_c_loop;

#if DYNAMIC_BMI2
    if (flags & HUF_flags_bmi2) {
        fallbackFn = HUF_decompress4X2_usingDTable_internal_bmi2;
# if ZSTD_ENABLE_ASM_X86_64_BMI2
        if (!(flags & HUF_flags_disableAsm)) {
            loopFn = HUF_decompress4X2_usingDTable_internal_fast_asm_loop;
        }
# endif
    } else {
        return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable);
    }
#endif

#if ZSTD_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__)
    if (!(flags & HUF_flags_disableAsm)) {
        loopFn = HUF_decompress4X2_usingDTable_internal_fast_asm_loop;
    }
#endif

    if (HUF_ENABLE_FAST_DECODE && !(flags & HUF_flags_disableFast)) {
        size_t const ret = HUF_decompress4X2_usingDTable_internal_fast(dst, dstSize, cSrc, cSrcSize, DTable, loopFn);
        if (ret != 0)
            return ret;
    }
    return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable);
}

HUF_DGEN(HUF_decompress1X2_usingDTable_internal)

size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize,
                                   const void* cSrc, size_t cSrcSize,
                                   void* workSpace, size_t wkspSize, int flags)
{
    const BYTE* ip = (const BYTE*) cSrc;

    size_t const hSize = HUF_readDTableX2_wksp(DCtx, cSrc, cSrcSize,
                                               workSpace, wkspSize, flags);
    if (HUF_isError(hSize)) return hSize;
    if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
    ip += hSize; cSrcSize -= hSize;

    return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, flags);
}

static size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                   const void* cSrc, size_t cSrcSize,
                                   void* workSpace, size_t wkspSize, int flags)
{
    const BYTE* ip = (const BYTE*) cSrc;

    size_t hSize = HUF_readDTableX2_wksp(dctx, cSrc, cSrcSize,
                                         workSpace, wkspSize, flags);
    if (HUF_isError(hSize)) return hSize;
    if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
    ip += hSize; cSrcSize -= hSize;

    return HUF_decompress4X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags);
}

#endif /* HUF_FORCE_DECOMPRESS_X1 */


/* ***********************************/
/* Universal decompression selectors */
/* ***********************************/


#if !defined(HUF_FORCE_DECOMPRESS_X1) && !defined(HUF_FORCE_DECOMPRESS_X2)
typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
static const algo_time_t algoTime[16 /* Quantization */][2 /* single, double */] =
{
    /* single, double, quad */
    {{0,0}, {1,1}},  /* Q==0 : impossible */
    {{0,0}, {1,1}},  /* Q==1 : impossible */
    {{ 150,216}, { 381,119}},   /* Q == 2 : 12-18% */
    {{ 170,205}, { 514,112}},   /* Q == 3 : 18-25% */
    {{ 177,199}, { 539,110}},   /* Q == 4 : 25-32% */
    {{ 197,194}, { 644,107}},   /* Q == 5 : 32-38% */
    {{ 221,192}, { 735,107}},   /* Q == 6 : 38-44% */
    {{ 256,189}, { 881,106}},   /* Q == 7 : 44-50% */
    {{ 359,188}, {1167,109}},   /* Q == 8 : 50-56% */
    {{ 582,187}, {1570,114}},   /* Q == 9 : 56-62% */
    {{ 688,187}, {1712,122}},   /* Q ==10 : 62-69% */
    {{ 825,186}, {1965,136}},   /* Q ==11 : 69-75% */
    {{ 976,185}, {2131,150}},   /* Q ==12 : 75-81% */
    {{1180,186}, {2070,175}},   /* Q ==13 : 81-87% */
    {{1377,185}, {1731,202}},   /* Q ==14 : 87-93% */
    {{1412,185}, {1695,202}},   /* Q ==15 : 93-99% */
};
#endif

/** HUF_selectDecoder() :
 *  Tells which decoder is likely to decode faster,
 *  based on a set of pre-computed metrics.
 * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 .
 *  Assumption : 0 < dstSize <= 128 KB */
U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize)
{
    assert(dstSize > 0);
    assert(dstSize <= 128*1024);
#if defined(HUF_FORCE_DECOMPRESS_X1)
    (void)dstSize;
    (void)cSrcSize;
    return 0;
#elif defined(HUF_FORCE_DECOMPRESS_X2)
    (void)dstSize;
    (void)cSrcSize;
    return 1;
#else
    /* decoder timing evaluation */
    {   U32 const Q = (cSrcSize >= dstSize) ? 15 : (U32)(cSrcSize * 16 / dstSize);   /* Q < 16 */
        U32 const D256 = (U32)(dstSize >> 8);
        U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256);
        U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256);
        DTime1 += DTime1 >> 5;  /* small advantage to algorithm using less memory, to reduce cache eviction */
        return DTime1 < DTime0;
    }
#endif
}

size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
                                  const void* cSrc, size_t cSrcSize,
                                  void* workSpace, size_t wkspSize, int flags)
{
    /* validation checks */
    if (dstSize == 0) return ERROR(dstSize_tooSmall);
    if (cSrcSize > dstSize) return ERROR(corruption_detected);   /* invalid */
    if (cSrcSize == dstSize) { ZSTD_memcpy(dst, cSrc, dstSize); return dstSize; }   /* not compressed */
    if (cSrcSize == 1) { ZSTD_memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; }   /* RLE */

    {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
#if defined(HUF_FORCE_DECOMPRESS_X1)
        (void)algoNb;
        assert(algoNb == 0);
        return HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                cSrcSize, workSpace, wkspSize, flags);
#elif defined(HUF_FORCE_DECOMPRESS_X2)
        (void)algoNb;
        assert(algoNb == 1);
        return HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                cSrcSize, workSpace, wkspSize, flags);
#else
        return algoNb ? HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                cSrcSize, workSpace, wkspSize, flags):
                        HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc,
                                cSrcSize, workSpace, wkspSize, flags);
#endif
    }
}


size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags)
{
    DTableDesc const dtd = HUF_getDTableDesc(DTable);
#if defined(HUF_FORCE_DECOMPRESS_X1)
    (void)dtd;
    assert(dtd.tableType == 0);
    return HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags);
#elif defined(HUF_FORCE_DECOMPRESS_X2)
    (void)dtd;
    assert(dtd.tableType == 1);
    return HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags);
#else
    return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags) :
                           HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags);
#endif
}

#ifndef HUF_FORCE_DECOMPRESS_X2
size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags)
{
    const BYTE* ip = (const BYTE*) cSrc;

    size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags);
    if (HUF_isError(hSize)) return hSize;
    if (hSize >= cSrcSize) return ERROR(srcSize_wrong);
    ip += hSize; cSrcSize -= hSize;

    return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags);
}
#endif

size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags)
{
    DTableDesc const dtd = HUF_getDTableDesc(DTable);
#if defined(HUF_FORCE_DECOMPRESS_X1)
    (void)dtd;
    assert(dtd.tableType == 0);
    return HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags);
#elif defined(HUF_FORCE_DECOMPRESS_X2)
    (void)dtd;
    assert(dtd.tableType == 1);
    return HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags);
#else
    return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags) :
                           HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags);
#endif
}

size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags)
{
    /* validation checks */
    if (dstSize == 0) return ERROR(dstSize_tooSmall);
    if (cSrcSize == 0) return ERROR(corruption_detected);

    {   U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize);
#if defined(HUF_FORCE_DECOMPRESS_X1)
        (void)algoNb;
        assert(algoNb == 0);
        return HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags);
#elif defined(HUF_FORCE_DECOMPRESS_X2)
        (void)algoNb;
        assert(algoNb == 1);
        return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags);
#else
        return algoNb ? HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags) :
                        HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags);
#endif
    }
}
/**** ended inlining decompress/huf_decompress.c ****/
/**** start inlining decompress/zstd_ddict.c ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* zstd_ddict.c :
 * concentrates all logic that needs to know the internals of ZSTD_DDict object */

/*-*******************************************************
*  Dependencies
*********************************************************/
/**** start inlining ../common/allocations.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* This file provides custom allocation primitives
 */

#define ZSTD_DEPS_NEED_MALLOC
/**** skipping file: zstd_deps.h ****/

/**** skipping file: compiler.h ****/
#define ZSTD_STATIC_LINKING_ONLY
/**** skipping file: ../zstd.h ****/

#ifndef ZSTD_ALLOCATIONS_H
#define ZSTD_ALLOCATIONS_H

/* custom memory allocation functions */

#endif /* ZSTD_ALLOCATIONS_H */
/**** ended inlining ../common/allocations.h ****/
/**** skipping file: ../common/zstd_deps.h ****/
/**** skipping file: ../common/cpu.h ****/
/**** skipping file: ../common/mem.h ****/
#define FSE_STATIC_LINKING_ONLY
/**** skipping file: ../common/fse.h ****/
/**** skipping file: ../common/huf.h ****/
/**** start inlining zstd_decompress_internal.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */


/* zstd_decompress_internal:
 * objects and definitions shared within lib/decompress modules */

 #ifndef ZSTD_DECOMPRESS_INTERNAL_H
 #define ZSTD_DECOMPRESS_INTERNAL_H


/*-*******************************************************
 *  Dependencies
 *********************************************************/
/**** skipping file: ../common/mem.h ****/
/**** skipping file: ../common/zstd_internal.h ****/



/*-*******************************************************
 *  Constants
 *********************************************************/
static UNUSED_ATTR const U32 LL_base[MaxLL+1] = {
                 0,    1,    2,     3,     4,     5,     6,      7,
                 8,    9,   10,    11,    12,    13,    14,     15,
                16,   18,   20,    22,    24,    28,    32,     40,
                48,   64, 0x80, 0x100, 0x200, 0x400, 0x800, 0x1000,
                0x2000, 0x4000, 0x8000, 0x10000 };

static UNUSED_ATTR const U32 OF_base[MaxOff+1] = {
                 0,        1,       1,       5,     0xD,     0x1D,     0x3D,     0x7D,
                 0xFD,   0x1FD,   0x3FD,   0x7FD,   0xFFD,   0x1FFD,   0x3FFD,   0x7FFD,
                 0xFFFD, 0x1FFFD, 0x3FFFD, 0x7FFFD, 0xFFFFD, 0x1FFFFD, 0x3FFFFD, 0x7FFFFD,
                 0xFFFFFD, 0x1FFFFFD, 0x3FFFFFD, 0x7FFFFFD, 0xFFFFFFD, 0x1FFFFFFD, 0x3FFFFFFD, 0x7FFFFFFD };

static UNUSED_ATTR const U8 OF_bits[MaxOff+1] = {
                     0,  1,  2,  3,  4,  5,  6,  7,
                     8,  9, 10, 11, 12, 13, 14, 15,
                    16, 17, 18, 19, 20, 21, 22, 23,
                    24, 25, 26, 27, 28, 29, 30, 31 };

static UNUSED_ATTR const U32 ML_base[MaxML+1] = {
                     3,  4,  5,    6,     7,     8,     9,    10,
                    11, 12, 13,   14,    15,    16,    17,    18,
                    19, 20, 21,   22,    23,    24,    25,    26,
                    27, 28, 29,   30,    31,    32,    33,    34,
                    35, 37, 39,   41,    43,    47,    51,    59,
                    67, 83, 99, 0x83, 0x103, 0x203, 0x403, 0x803,
                    0x1003, 0x2003, 0x4003, 0x8003, 0x10003 };


/*-*******************************************************
 *  Decompression types
 *********************************************************/
 typedef struct {
     U32 fastMode;
     U32 tableLog;
 } ZSTD_seqSymbol_header;

 typedef struct {
     U16  nextState;
     BYTE nbAdditionalBits;
     BYTE nbBits;
     U32  baseValue;
 } ZSTD_seqSymbol;

 #define SEQSYMBOL_TABLE_SIZE(log)   (1 + (1 << (log)))

#define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE (sizeof(S16) * (MaxSeq + 1) + (1u << MaxFSELog) + sizeof(U64))
#define ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32 ((ZSTD_BUILD_FSE_TABLE_WKSP_SIZE + sizeof(U32) - 1) / sizeof(U32))
#define ZSTD_HUFFDTABLE_CAPACITY_LOG 12

typedef struct {
    ZSTD_seqSymbol LLTable[SEQSYMBOL_TABLE_SIZE(LLFSELog)];    /* Note : Space reserved for FSE Tables */
    ZSTD_seqSymbol OFTable[SEQSYMBOL_TABLE_SIZE(OffFSELog)];   /* is also used as temporary workspace while building hufTable during DDict creation */
    ZSTD_seqSymbol MLTable[SEQSYMBOL_TABLE_SIZE(MLFSELog)];    /* and therefore must be at least HUF_DECOMPRESS_WORKSPACE_SIZE large */
    HUF_DTable hufTable[HUF_DTABLE_SIZE(ZSTD_HUFFDTABLE_CAPACITY_LOG)];  /* can accommodate HUF_decompress4X */
    U32 rep[ZSTD_REP_NUM];
    U32 workspace[ZSTD_BUILD_FSE_TABLE_WKSP_SIZE_U32];
} ZSTD_entropyDTables_t;

typedef enum { ZSTDds_getFrameHeaderSize, ZSTDds_decodeFrameHeader,
               ZSTDds_decodeBlockHeader, ZSTDds_decompressBlock,
               ZSTDds_decompressLastBlock, ZSTDds_checkChecksum,
               ZSTDds_decodeSkippableHeader, ZSTDds_skipFrame } ZSTD_dStage;

typedef enum { zdss_init=0, zdss_loadHeader,
               zdss_read, zdss_load, zdss_flush } ZSTD_dStreamStage;

typedef enum {
    ZSTD_use_indefinitely = -1,  /* Use the dictionary indefinitely */
    ZSTD_dont_use = 0,           /* Do not use the dictionary (if one exists free it) */
    ZSTD_use_once = 1            /* Use the dictionary once and set to ZSTD_dont_use */
} ZSTD_dictUses_e;

/* Hashset for storing references to multiple ZSTD_DDict within ZSTD_DCtx */
typedef struct {
    const ZSTD_DDict** ddictPtrTable;
    size_t ddictPtrTableSize;
    size_t ddictPtrCount;
} ZSTD_DDictHashSet;

#ifndef ZSTD_DECODER_INTERNAL_BUFFER
#  define ZSTD_DECODER_INTERNAL_BUFFER  (1 << 16)
#endif

#define ZSTD_LBMIN 64
#define ZSTD_LBMAX (128 << 10)

/* extra buffer, compensates when dst is not large enough to store litBuffer */
#define ZSTD_LITBUFFEREXTRASIZE  BOUNDED(ZSTD_LBMIN, ZSTD_DECODER_INTERNAL_BUFFER, ZSTD_LBMAX)

typedef enum {
    ZSTD_not_in_dst = 0,  /* Stored entirely within litExtraBuffer */
    ZSTD_in_dst = 1,           /* Stored entirely within dst (in memory after current output write) */
    ZSTD_split = 2            /* Split between litExtraBuffer and dst */
} ZSTD_litLocation_e;

struct ZSTD_DCtx_s
{
    const ZSTD_seqSymbol* LLTptr;
    const ZSTD_seqSymbol* MLTptr;
    const ZSTD_seqSymbol* OFTptr;
    const HUF_DTable* HUFptr;
    ZSTD_entropyDTables_t entropy;
    U32 workspace[HUF_DECOMPRESS_WORKSPACE_SIZE_U32];   /* space needed when building huffman tables */
    const void* previousDstEnd;   /* detect continuity */
    const void* prefixStart;      /* start of current segment */
    const void* virtualStart;     /* virtual start of previous segment if it was just before current one */
    const void* dictEnd;          /* end of previous segment */
    size_t expected;
    ZSTD_frameHeader fParams;
    U64 processedCSize;
    U64 decodedSize;
    blockType_e bType;            /* used in ZSTD_decompressContinue(), store blockType between block header decoding and block decompression stages */
    ZSTD_dStage stage;
    U32 litEntropy;
    U32 fseEntropy;
    XXH64_state_t xxhState;
    size_t headerSize;
    ZSTD_format_e format;
    ZSTD_forceIgnoreChecksum_e forceIgnoreChecksum;   /* User specified: if == 1, will ignore checksums in compressed frame. Default == 0 */
    U32 validateChecksum;         /* if == 1, will validate checksum. Is == 1 if (fParams.checksumFlag == 1) and (forceIgnoreChecksum == 0). */
    const BYTE* litPtr;
    ZSTD_customMem customMem;
    size_t litSize;
    size_t rleSize;
    size_t staticSize;
    int isFrameDecompression;
#if DYNAMIC_BMI2 != 0
    int bmi2;                     /* == 1 if the CPU supports BMI2 and 0 otherwise. CPU support is determined dynamically once per context lifetime. */
#endif

    /* dictionary */
    ZSTD_DDict* ddictLocal;
    const ZSTD_DDict* ddict;     /* set by ZSTD_initDStream_usingDDict(), or ZSTD_DCtx_refDDict() */
    U32 dictID;
    int ddictIsCold;             /* if == 1 : dictionary is "new" for working context, and presumed "cold" (not in cpu cache) */
    ZSTD_dictUses_e dictUses;
    ZSTD_DDictHashSet* ddictSet;                    /* Hash set for multiple ddicts */
    ZSTD_refMultipleDDicts_e refMultipleDDicts;     /* User specified: if == 1, will allow references to multiple DDicts. Default == 0 (disabled) */
    int disableHufAsm;
    int maxBlockSizeParam;

    /* streaming */
    ZSTD_dStreamStage streamStage;
    char*  inBuff;
    size_t inBuffSize;
    size_t inPos;
    size_t maxWindowSize;
    char*  outBuff;
    size_t outBuffSize;
    size_t outStart;
    size_t outEnd;
    size_t lhSize;
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
    void* legacyContext;
    U32 previousLegacyVersion;
    U32 legacyVersion;
#endif
    U32 hostageByte;
    int noForwardProgress;
    ZSTD_bufferMode_e outBufferMode;
    ZSTD_outBuffer expectedOutBuffer;

    /* workspace */
    BYTE* litBuffer;
    const BYTE* litBufferEnd;
    ZSTD_litLocation_e litBufferLocation;
    BYTE litExtraBuffer[ZSTD_LITBUFFEREXTRASIZE + WILDCOPY_OVERLENGTH]; /* literal buffer can be split between storage within dst and within this scratch buffer */
    BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];

    size_t oversizedDuration;

#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
    void const* dictContentBeginForFuzzing;
    void const* dictContentEndForFuzzing;
#endif

    /* Tracing */
#if ZSTD_TRACE
    ZSTD_TraceCtx traceCtx;
#endif
};  /* typedef'd to ZSTD_DCtx within "zstd.h" */

MEM_STATIC int ZSTD_DCtx_get_bmi2(const struct ZSTD_DCtx_s *dctx) {
#if DYNAMIC_BMI2 != 0
        return dctx->bmi2;
#else
    (void)dctx;
        return 0;
#endif
}

/*-*******************************************************
 *  Shared internal functions
 *********************************************************/

/*! ZSTD_loadDEntropy() :
 *  dict : must point at beginning of a valid zstd dictionary.
 * @return : size of dictionary header (size of magic number + dict ID + entropy tables) */
size_t ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
                   const void* const dict, size_t const dictSize);

/*! ZSTD_checkContinuity() :
 *  check if next `dst` follows previous position, where decompression ended.
 *  If yes, do nothing (continue on current segment).
 *  If not, classify previous segment as "external dictionary", and start a new segment.
 *  This function cannot fail. */
void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize);


#endif /* ZSTD_DECOMPRESS_INTERNAL_H */
/**** ended inlining zstd_decompress_internal.h ****/
/**** start inlining zstd_ddict.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */


#ifndef ZSTD_DDICT_H
#define ZSTD_DDICT_H

/*-*******************************************************
 *  Dependencies
 *********************************************************/
/**** skipping file: ../common/zstd_deps.h ****/
/**** skipping file: ../zstd.h ****/


/*-*******************************************************
 *  Interface
 *********************************************************/

/* note: several prototypes are already published in `zstd.h` :
 * ZSTD_createDDict()
 * ZSTD_createDDict_byReference()
 * ZSTD_createDDict_advanced()
 * ZSTD_freeDDict()
 * ZSTD_initStaticDDict()
 * ZSTD_sizeof_DDict()
 * ZSTD_estimateDDictSize()
 * ZSTD_getDictID_fromDict()
 */

const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict);
size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict);

void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);



#endif /* ZSTD_DDICT_H */
/**** ended inlining zstd_ddict.h ****/

#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
#error Using excluded file: ../legacy/zstd_legacy.h (re-amalgamate source to fix)
#endif



/*-*******************************************************
*  Types
*********************************************************/
struct ZSTD_DDict_s {
    void* dictBuffer;
    const void* dictContent;
    size_t dictSize;
    ZSTD_entropyDTables_t entropy;
    U32 dictID;
    U32 entropyPresent;
    ZSTD_customMem cMem;
};  /* typedef'd to ZSTD_DDict within "zstd.h" */

const void* ZSTD_DDict_dictContent(const ZSTD_DDict* ddict)
{
    assert(ddict != NULL);
    return ddict->dictContent;
}

size_t ZSTD_DDict_dictSize(const ZSTD_DDict* ddict)
{
    assert(ddict != NULL);
    return ddict->dictSize;
}

void ZSTD_copyDDictParameters(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
{
    DEBUGLOG(4, "ZSTD_copyDDictParameters");
    assert(dctx != NULL);
    assert(ddict != NULL);
    dctx->dictID = ddict->dictID;
    dctx->prefixStart = ddict->dictContent;
    dctx->virtualStart = ddict->dictContent;
    dctx->dictEnd = (const BYTE*)ddict->dictContent + ddict->dictSize;
    dctx->previousDstEnd = dctx->dictEnd;
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
    dctx->dictContentBeginForFuzzing = dctx->prefixStart;
    dctx->dictContentEndForFuzzing = dctx->previousDstEnd;
#endif
    if (ddict->entropyPresent) {
        dctx->litEntropy = 1;
        dctx->fseEntropy = 1;
        dctx->LLTptr = ddict->entropy.LLTable;
        dctx->MLTptr = ddict->entropy.MLTable;
        dctx->OFTptr = ddict->entropy.OFTable;
        dctx->HUFptr = ddict->entropy.hufTable;
        dctx->entropy.rep[0] = ddict->entropy.rep[0];
        dctx->entropy.rep[1] = ddict->entropy.rep[1];
        dctx->entropy.rep[2] = ddict->entropy.rep[2];
    } else {
        dctx->litEntropy = 0;
        dctx->fseEntropy = 0;
    }
}


static size_t
ZSTD_loadEntropy_intoDDict(ZSTD_DDict* ddict,
                           ZSTD_dictContentType_e dictContentType)
{
    ddict->dictID = 0;
    ddict->entropyPresent = 0;
    if (dictContentType == ZSTD_dct_rawContent) return 0;

    if (ddict->dictSize < 8) {
        if (dictContentType == ZSTD_dct_fullDict)
            return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
        return 0;   /* pure content mode */
    }
    {   U32 const magic = MEM_readLE32(ddict->dictContent);
        if (magic != ZSTD_MAGIC_DICTIONARY) {
            if (dictContentType == ZSTD_dct_fullDict)
                return ERROR(dictionary_corrupted);   /* only accept specified dictionaries */
            return 0;   /* pure content mode */
        }
    }
    ddict->dictID = MEM_readLE32((const char*)ddict->dictContent + ZSTD_FRAMEIDSIZE);

    /* load entropy tables */
    RETURN_ERROR_IF(ZSTD_isError(ZSTD_loadDEntropy(
            &ddict->entropy, ddict->dictContent, ddict->dictSize)),
        dictionary_corrupted, "");
    ddict->entropyPresent = 1;
    return 0;
}


static size_t ZSTD_initDDict_internal(ZSTD_DDict* ddict,
                                      const void* dict, size_t dictSize,
                                      ZSTD_dictLoadMethod_e dictLoadMethod,
                                      ZSTD_dictContentType_e dictContentType)
{
    if ((dictLoadMethod == ZSTD_dlm_byRef) || (!dict) || (!dictSize)) {
        ddict->dictBuffer = NULL;
        ddict->dictContent = dict;
        if (!dict) dictSize = 0;
    } else {
        void* const internalBuffer = VG_(malloc)("zstddeclib.ZSTD_initDDict_internal.1", dictSize);
        ddict->dictBuffer = internalBuffer;
        ddict->dictContent = internalBuffer;
        if (!internalBuffer) return ERROR(memory_allocation);
        ZSTD_memcpy(internalBuffer, dict, dictSize);
    }
    ddict->dictSize = dictSize;
    ddict->entropy.hufTable[0] = (HUF_DTable)((ZSTD_HUFFDTABLE_CAPACITY_LOG)*0x1000001);  /* cover both little and big endian */

    /* parse dictionary content */
    FORWARD_IF_ERROR( ZSTD_loadEntropy_intoDDict(ddict, dictContentType) , "");

    return 0;
}

ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
                                      ZSTD_dictLoadMethod_e dictLoadMethod,
                                      ZSTD_dictContentType_e dictContentType,
                                      ZSTD_customMem customMem)
{
    if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL;

    {   ZSTD_DDict* const ddict = (ZSTD_DDict*) VG_(malloc)("zstddeclib.ZSTD_createDDict_advanced.1", sizeof(ZSTD_DDict));
        if (ddict == NULL) return NULL;
        ddict->cMem = customMem;
        {   size_t const initResult = ZSTD_initDDict_internal(ddict,
                                            dict, dictSize,
                                            dictLoadMethod, dictContentType);
            if (ZSTD_isError(initResult)) {
                ZSTD_freeDDict(ddict);
                return NULL;
        }   }
        return ddict;
    }
}

/*! ZSTD_createDDict() :
*   Create a digested dictionary, to start decompression without startup delay.
*   `dict` content is copied inside DDict.
*   Consequently, `dict` can be released after `ZSTD_DDict` creation */
ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize)
{
    ZSTD_customMem const allocator = { NULL, NULL, NULL };
    return ZSTD_createDDict_advanced(dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto, allocator);
}

/*! ZSTD_createDDict_byReference() :
 *  Create a digested dictionary, to start decompression without startup delay.
 *  Dictionary content is simply referenced, it will be accessed during decompression.
 *  Warning : dictBuffer must outlive DDict (DDict must be freed before dictBuffer) */
ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize)
{
    ZSTD_customMem const allocator = { NULL, NULL, NULL };
    return ZSTD_createDDict_advanced(dictBuffer, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto, allocator);
}


const ZSTD_DDict* ZSTD_initStaticDDict(
                                void* sBuffer, size_t sBufferSize,
                                const void* dict, size_t dictSize,
                                ZSTD_dictLoadMethod_e dictLoadMethod,
                                ZSTD_dictContentType_e dictContentType)
{
    size_t const neededSpace = sizeof(ZSTD_DDict)
                             + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
    ZSTD_DDict* const ddict = (ZSTD_DDict*)sBuffer;
    assert(sBuffer != NULL);
    assert(dict != NULL);
    if ((size_t)sBuffer & 7) return NULL;   /* 8-aligned */
    if (sBufferSize < neededSpace) return NULL;
    if (dictLoadMethod == ZSTD_dlm_byCopy) {
        ZSTD_memcpy(ddict+1, dict, dictSize);  /* local copy */
        dict = ddict+1;
    }
    if (ZSTD_isError( ZSTD_initDDict_internal(ddict,
                                              dict, dictSize,
                                              ZSTD_dlm_byRef, dictContentType) ))
        return NULL;
    return ddict;
}


size_t ZSTD_freeDDict(ZSTD_DDict* ddict)
{
    if (ddict==NULL) return 0;   /* support free on NULL */
    {
        VG_(free)(ddict->dictBuffer);
        VG_(free)(ddict);
        return 0;
    }
}

/*! ZSTD_estimateDDictSize() :
 *  Estimate amount of memory that will be needed to create a dictionary for decompression.
 *  Note : dictionary created by reference using ZSTD_dlm_byRef are smaller */
size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod)
{
    return sizeof(ZSTD_DDict) + (dictLoadMethod == ZSTD_dlm_byRef ? 0 : dictSize);
}

size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict)
{
    if (ddict==NULL) return 0;   /* support sizeof on NULL */
    return sizeof(*ddict) + (ddict->dictBuffer ? ddict->dictSize : 0) ;
}

/*! ZSTD_getDictID_fromDDict() :
 *  Provides the dictID of the dictionary loaded into `ddict`.
 *  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
 *  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. */
unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict)
{
    if (ddict==NULL) return 0;
    return ddict->dictID;
}
/**** ended inlining decompress/zstd_ddict.c ****/
/**** start inlining decompress/zstd_decompress.c ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */


/* ***************************************************************
*  Tuning parameters
*****************************************************************/
/*!
 * HEAPMODE :
 * Select how default decompression function ZSTD_decompress() allocates its context,
 * on stack (0), or into heap (1, default; requires malloc()).
 * Note that functions with explicit context such as ZSTD_decompressDCtx() are unaffected.
 */
#ifndef ZSTD_HEAPMODE
#  define ZSTD_HEAPMODE 1
#endif

/*!
*  LEGACY_SUPPORT :
*  if set to 1+, ZSTD_decompress() can decode older formats (v0.1+)
*/
#ifndef ZSTD_LEGACY_SUPPORT
#  define ZSTD_LEGACY_SUPPORT 0
#endif

/*!
 *  MAXWINDOWSIZE_DEFAULT :
 *  maximum window size accepted by DStream __by default__.
 *  Frames requiring more memory will be rejected.
 *  It's possible to set a different limit using ZSTD_DCtx_setMaxWindowSize().
 */
#ifndef ZSTD_MAXWINDOWSIZE_DEFAULT
#  define ZSTD_MAXWINDOWSIZE_DEFAULT (((U32)1 << ZSTD_WINDOWLOG_LIMIT_DEFAULT) + 1)
#endif

/*!
 *  NO_FORWARD_PROGRESS_MAX :
 *  maximum allowed nb of calls to ZSTD_decompressStream()
 *  without any forward progress
 *  (defined as: no byte read from input, and no byte flushed to output)
 *  before triggering an error.
 */
#ifndef ZSTD_NO_FORWARD_PROGRESS_MAX
#  define ZSTD_NO_FORWARD_PROGRESS_MAX 16
#endif


/*-*******************************************************
*  Dependencies
*********************************************************/
/**** skipping file: ../common/zstd_deps.h ****/
/**** skipping file: ../common/allocations.h ****/
/**** skipping file: ../common/error_private.h ****/
/**** skipping file: ../common/zstd_internal.h ****/
/**** skipping file: ../common/mem.h ****/
/**** skipping file: ../common/bits.h ****/
#define FSE_STATIC_LINKING_ONLY
/**** skipping file: ../common/fse.h ****/
/**** skipping file: ../common/huf.h ****/
/**** skipping file: ../common/xxhash.h ****/
/**** skipping file: zstd_decompress_internal.h ****/
/**** skipping file: zstd_ddict.h ****/
/**** start inlining zstd_decompress_block.h ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */


#ifndef ZSTD_DEC_BLOCK_H
#define ZSTD_DEC_BLOCK_H

/*-*******************************************************
 *  Dependencies
 *********************************************************/
/**** skipping file: ../common/zstd_deps.h ****/
/**** skipping file: ../zstd.h ****/
/**** skipping file: ../common/zstd_internal.h ****/
/**** skipping file: zstd_decompress_internal.h ****/


/* ===   Prototypes   === */

/* note: prototypes already published within `zstd.h` :
 * ZSTD_decompressBlock()
 */

/* note: prototypes already published within `zstd_internal.h` :
 * ZSTD_getcBlockSize()
 * ZSTD_decodeSeqHeaders()
 */


 /* Streaming state is used to inform allocation of the literal buffer */
typedef enum {
    not_streaming = 0,
    is_streaming = 1
} streaming_operation;

/* ZSTD_decompressBlock_internal() :
 * decompress block, starting at `src`,
 * into destination buffer `dst`.
 * @return : decompressed block size,
 *           or an error code (which can be tested using ZSTD_isError())
 */
size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
                               void* dst, size_t dstCapacity,
                         const void* src, size_t srcSize, const streaming_operation streaming);

/* ZSTD_buildFSETable() :
 * generate FSE decoding table for one symbol (ll, ml or off)
 * this function must be called with valid parameters only
 * (dt is large enough, normalizedCounter distribution total is a power of 2, max is within range, etc.)
 * in which case it cannot fail.
 * The workspace must be 4-byte aligned and at least ZSTD_BUILD_FSE_TABLE_WKSP_SIZE bytes, which is
 * defined in zstd_decompress_internal.h.
 * Internal use only.
 */
void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
             const short* normalizedCounter, unsigned maxSymbolValue,
             const U32* baseValue, const U8* nbAdditionalBits,
                   unsigned tableLog, void* wksp, size_t wkspSize,
                   int bmi2);

/* Internal definition of ZSTD_decompressBlock() to avoid deprecation warnings. */
size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize);


#endif /* ZSTD_DEC_BLOCK_H */
/**** ended inlining zstd_decompress_block.h ****/

#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
#error Using excluded file: ../legacy/zstd_legacy.h (re-amalgamate source to fix)
#endif



/*************************************
 * Multiple DDicts Hashset internals *
 *************************************/

#define DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT 4
#define DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT 3  /* These two constants represent SIZE_MULT/COUNT_MULT load factor without using a float.
                                                    * Currently, that means a 0.75 load factor.
                                                    * So, if count * COUNT_MULT / size * SIZE_MULT != 0, then we've exceeded
                                                    * the load factor of the ddict hash set.
                                                    */

#define DDICT_HASHSET_TABLE_BASE_SIZE 64
#define DDICT_HASHSET_RESIZE_FACTOR 2

/* Hash function to determine starting position of dict insertion within the table
 * Returns an index between [0, hashSet->ddictPtrTableSize]
 */
static size_t ZSTD_DDictHashSet_getIndex(const ZSTD_DDictHashSet* hashSet, U32 dictID) {
    const U64 hash = XXH64(&dictID, sizeof(U32), 0);
    /* DDict ptr table size is a multiple of 2, use size - 1 as mask to get index within [0, hashSet->ddictPtrTableSize) */
    return hash & (hashSet->ddictPtrTableSize - 1);
}

/* Adds DDict to a hashset without resizing it.
 * If inserting a DDict with a dictID that already exists in the set, replaces the one in the set.
 * Returns 0 if successful, or a zstd error code if something went wrong.
 */
static size_t ZSTD_DDictHashSet_emplaceDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict) {
    const U32 dictID = ZSTD_getDictID_fromDDict(ddict);
    size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
    const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1;
    RETURN_ERROR_IF(hashSet->ddictPtrCount == hashSet->ddictPtrTableSize, GENERIC, "Hash set is full!");
    DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
    while (hashSet->ddictPtrTable[idx] != NULL) {
        /* Replace existing ddict if inserting ddict with same dictID */
        if (ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]) == dictID) {
            DEBUGLOG(4, "DictID already exists, replacing rather than adding");
            hashSet->ddictPtrTable[idx] = ddict;
            return 0;
        }
        idx &= idxRangeMask;
        idx++;
    }
    DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx);
    hashSet->ddictPtrTable[idx] = ddict;
    hashSet->ddictPtrCount++;
    return 0;
}

/* Expands hash table by factor of DDICT_HASHSET_RESIZE_FACTOR and
 * rehashes all values, allocates new table, frees old table.
 * Returns 0 on success, otherwise a zstd error code.
 */
static size_t ZSTD_DDictHashSet_expand(ZSTD_DDictHashSet* hashSet, ZSTD_customMem customMem) {
    size_t newTableSize = hashSet->ddictPtrTableSize * DDICT_HASHSET_RESIZE_FACTOR;
    const ZSTD_DDict** newTable = (const ZSTD_DDict**)VG_(calloc)("zstddeclib.ZSTD_DDictHashSet_expand.1", 1, sizeof(ZSTD_DDict*) * newTableSize);
    const ZSTD_DDict** oldTable = hashSet->ddictPtrTable;
    size_t oldTableSize = hashSet->ddictPtrTableSize;
    size_t i;

    DEBUGLOG(4, "Expanding DDict hash table! Old size: %zu new size: %zu", oldTableSize, newTableSize);
    RETURN_ERROR_IF(!newTable, memory_allocation, "Expanded hashset allocation failed!");
    hashSet->ddictPtrTable = newTable;
    hashSet->ddictPtrTableSize = newTableSize;
    hashSet->ddictPtrCount = 0;
    for (i = 0; i < oldTableSize; ++i) {
        if (oldTable[i] != NULL) {
            FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, oldTable[i]), "");
        }
    }
    VG_(free)((void*)oldTable);
    DEBUGLOG(4, "Finished re-hash");
    return 0;
}

/* Fetches a DDict with the given dictID
 * Returns the ZSTD_DDict* with the requested dictID. If it doesn't exist, then returns NULL.
 */
static const ZSTD_DDict* ZSTD_DDictHashSet_getDDict(ZSTD_DDictHashSet* hashSet, U32 dictID) {
    size_t idx = ZSTD_DDictHashSet_getIndex(hashSet, dictID);
    const size_t idxRangeMask = hashSet->ddictPtrTableSize - 1;
    DEBUGLOG(4, "Hashed index: for dictID: %u is %zu", dictID, idx);
    for (;;) {
        size_t currDictID = ZSTD_getDictID_fromDDict(hashSet->ddictPtrTable[idx]);
        if (currDictID == dictID || currDictID == 0) {
            /* currDictID == 0 implies a NULL ddict entry */
            break;
        } else {
            idx &= idxRangeMask;    /* Goes to start of table when we reach the end */
            idx++;
        }
    }
    DEBUGLOG(4, "Final idx after probing for dictID %u is: %zu", dictID, idx);
    return hashSet->ddictPtrTable[idx];
}

/* Allocates space for and returns a ddict hash set
 * The hash set's ZSTD_DDict* table has all values automatically set to NULL to begin with.
 * Returns NULL if allocation failed.
 */
static ZSTD_DDictHashSet* ZSTD_createDDictHashSet(ZSTD_customMem customMem) {
    ZSTD_DDictHashSet* ret = (ZSTD_DDictHashSet*)VG_(malloc)("zstddeclib.ZSTD_createDDictHashSet.1", sizeof(ZSTD_DDictHashSet));
    DEBUGLOG(4, "Allocating new hash set");
    if (!ret)
        return NULL;
    ret->ddictPtrTable = (const ZSTD_DDict**)VG_(calloc)("zstddeclib.ZSTD_createDDictHashSet.2", 1, DDICT_HASHSET_TABLE_BASE_SIZE * sizeof(ZSTD_DDict*));
    if (!ret->ddictPtrTable) {
        VG_(free)(ret);
        return NULL;
    }
    ret->ddictPtrTableSize = DDICT_HASHSET_TABLE_BASE_SIZE;
    ret->ddictPtrCount = 0;
    return ret;
}

/* Frees the table of ZSTD_DDict* within a hashset, then frees the hashset itself.
 * Note: The ZSTD_DDict* within the table are NOT freed.
 */
static void ZSTD_freeDDictHashSet(ZSTD_DDictHashSet* hashSet) {
    DEBUGLOG(4, "Freeing ddict hash set");
    if (hashSet && hashSet->ddictPtrTable) {
        VG_(free)((void*)hashSet->ddictPtrTable);
    }
    if (hashSet) {
        VG_(free)(hashSet);
    }
}

/* Public function: Adds a DDict into the ZSTD_DDictHashSet, possibly triggering a resize of the hash set.
 * Returns 0 on success, or a ZSTD error.
 */
static size_t ZSTD_DDictHashSet_addDDict(ZSTD_DDictHashSet* hashSet, const ZSTD_DDict* ddict, ZSTD_customMem customMem) {
    DEBUGLOG(4, "Adding dict ID: %u to hashset with - Count: %zu Tablesize: %zu", ZSTD_getDictID_fromDDict(ddict), hashSet->ddictPtrCount, hashSet->ddictPtrTableSize);
    if (hashSet->ddictPtrCount * DDICT_HASHSET_MAX_LOAD_FACTOR_COUNT_MULT / hashSet->ddictPtrTableSize * DDICT_HASHSET_MAX_LOAD_FACTOR_SIZE_MULT != 0) {
        FORWARD_IF_ERROR(ZSTD_DDictHashSet_expand(hashSet, customMem), "");
    }
    FORWARD_IF_ERROR(ZSTD_DDictHashSet_emplaceDDict(hashSet, ddict), "");
    return 0;
}

/*-*************************************************************
*   Context management
***************************************************************/
size_t ZSTD_sizeof_DCtx (const ZSTD_DCtx* dctx)
{
    if (dctx==NULL) return 0;   /* support sizeof NULL */
    return sizeof(*dctx)
           + ZSTD_sizeof_DDict(dctx->ddictLocal)
           + dctx->inBuffSize + dctx->outBuffSize;
}

size_t ZSTD_estimateDCtxSize(void) { return sizeof(ZSTD_DCtx); }


static size_t ZSTD_startingInputLength(ZSTD_format_e format)
{
    size_t const startingInputLength = ZSTD_FRAMEHEADERSIZE_PREFIX(format);
    /* only supports formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless */
    assert( (format == ZSTD_f_zstd1) || (format == ZSTD_f_zstd1_magicless) );
    return startingInputLength;
}

static void ZSTD_DCtx_resetParameters(ZSTD_DCtx* dctx)
{
    assert(dctx->streamStage == zdss_init);
    dctx->format = ZSTD_f_zstd1;
    dctx->maxWindowSize = ZSTD_MAXWINDOWSIZE_DEFAULT;
    dctx->outBufferMode = ZSTD_bm_buffered;
    dctx->forceIgnoreChecksum = ZSTD_d_validateChecksum;
    dctx->refMultipleDDicts = ZSTD_rmd_refSingleDDict;
    dctx->disableHufAsm = 0;
    dctx->maxBlockSizeParam = 0;
}

static void ZSTD_initDCtx_internal(ZSTD_DCtx* dctx)
{
    dctx->staticSize  = 0;
    dctx->ddict       = NULL;
    dctx->ddictLocal  = NULL;
    dctx->dictEnd     = NULL;
    dctx->ddictIsCold = 0;
    dctx->dictUses = ZSTD_dont_use;
    dctx->inBuff      = NULL;
    dctx->inBuffSize  = 0;
    dctx->outBuffSize = 0;
    dctx->streamStage = zdss_init;
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
    dctx->legacyContext = NULL;
    dctx->previousLegacyVersion = 0;
#endif
    dctx->noForwardProgress = 0;
    dctx->oversizedDuration = 0;
    dctx->isFrameDecompression = 1;
#if DYNAMIC_BMI2
    dctx->bmi2 = ZSTD_cpuSupportsBmi2();
#endif
    dctx->ddictSet = NULL;
    ZSTD_DCtx_resetParameters(dctx);
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
    dctx->dictContentEndForFuzzing = NULL;
#endif
}

ZSTD_DCtx* ZSTD_initStaticDCtx(void *workspace, size_t workspaceSize)
{
    ZSTD_DCtx* const dctx = (ZSTD_DCtx*) workspace;

    if ((size_t)workspace & 7) return NULL;  /* 8-aligned */
    if (workspaceSize < sizeof(ZSTD_DCtx)) return NULL;  /* minimum size */

    ZSTD_initDCtx_internal(dctx);
    dctx->staticSize = workspaceSize;
    dctx->inBuff = (char*)(dctx+1);
    return dctx;
}

static ZSTD_DCtx* ZSTD_createDCtx_internal(ZSTD_customMem customMem) {
    if ((!customMem.customAlloc) ^ (!customMem.customFree)) return NULL;

    {   ZSTD_DCtx* const dctx = (ZSTD_DCtx*)VG_(malloc)("zstddeclib.ZSTD_createDCtx_internal.1", sizeof(*dctx));
        if (!dctx) return NULL;
        dctx->customMem = customMem;
        ZSTD_initDCtx_internal(dctx);
        return dctx;
    }
}

ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem)
{
    return ZSTD_createDCtx_internal(customMem);
}

ZSTD_DCtx* ZSTD_createDCtx(void)
{
    DEBUGLOG(3, "ZSTD_createDCtx");
    return ZSTD_createDCtx_internal(ZSTD_defaultCMem);
}

static void ZSTD_clearDict(ZSTD_DCtx* dctx)
{
    ZSTD_freeDDict(dctx->ddictLocal);
    dctx->ddictLocal = NULL;
    dctx->ddict = NULL;
    dctx->dictUses = ZSTD_dont_use;
}

size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx)
{
    if (dctx==NULL) return 0;   /* support free on NULL */
    RETURN_ERROR_IF(dctx->staticSize, memory_allocation, "not compatible with static DCtx");
    {
        ZSTD_clearDict(dctx);
        VG_(free)(dctx->inBuff);
        dctx->inBuff = NULL;
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
        if (dctx->legacyContext)
            ZSTD_freeLegacyStreamContext(dctx->legacyContext, dctx->previousLegacyVersion);
#endif
        if (dctx->ddictSet) {
            ZSTD_freeDDictHashSet(dctx->ddictSet);
            dctx->ddictSet = NULL;
        }
        VG_(free)(dctx);
        return 0;
    }
}

/* no longer useful */
void ZSTD_copyDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
{
    size_t const toCopy = (size_t)((char*)(&dstDCtx->inBuff) - (char*)dstDCtx);
    ZSTD_memcpy(dstDCtx, srcDCtx, toCopy);  /* no need to copy workspace */
}

/* Given a dctx with a digested frame params, re-selects the correct ZSTD_DDict based on
 * the requested dict ID from the frame. If there exists a reference to the correct ZSTD_DDict, then
 * accordingly sets the ddict to be used to decompress the frame.
 *
 * If no DDict is found, then no action is taken, and the ZSTD_DCtx::ddict remains as-is.
 *
 * ZSTD_d_refMultipleDDicts must be enabled for this function to be called.
 */
static void ZSTD_DCtx_selectFrameDDict(ZSTD_DCtx* dctx) {
    assert(dctx->refMultipleDDicts && dctx->ddictSet);
    DEBUGLOG(4, "Adjusting DDict based on requested dict ID from frame");
    if (dctx->ddict) {
        const ZSTD_DDict* frameDDict = ZSTD_DDictHashSet_getDDict(dctx->ddictSet, dctx->fParams.dictID);
        if (frameDDict) {
            DEBUGLOG(4, "DDict found!");
            ZSTD_clearDict(dctx);
            dctx->dictID = dctx->fParams.dictID;
            dctx->ddict = frameDDict;
            dctx->dictUses = ZSTD_use_indefinitely;
        }
    }
}


/*-*************************************************************
 *   Frame header decoding
 ***************************************************************/

/*! ZSTD_isFrame() :
 *  Tells if the content of `buffer` starts with a valid Frame Identifier.
 *  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
 *  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
 *  Note 3 : Skippable Frame Identifiers are considered valid. */
unsigned ZSTD_isFrame(const void* buffer, size_t size)
{
    if (size < ZSTD_FRAMEIDSIZE) return 0;
    {   U32 const magic = MEM_readLE32(buffer);
        if (magic == ZSTD_MAGICNUMBER) return 1;
        if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
    }
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
    if (ZSTD_isLegacy(buffer, size)) return 1;
#endif
    return 0;
}

/*! ZSTD_isSkippableFrame() :
 *  Tells if the content of `buffer` starts with a valid Frame Identifier for a skippable frame.
 *  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
 */
unsigned ZSTD_isSkippableFrame(const void* buffer, size_t size)
{
    if (size < ZSTD_FRAMEIDSIZE) return 0;
    {   U32 const magic = MEM_readLE32(buffer);
        if ((magic & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) return 1;
    }
    return 0;
}

/** ZSTD_frameHeaderSize_internal() :
 *  srcSize must be large enough to reach header size fields.
 *  note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless.
 * @return : size of the Frame Header
 *           or an error code, which can be tested with ZSTD_isError() */
static size_t ZSTD_frameHeaderSize_internal(const void* src, size_t srcSize, ZSTD_format_e format)
{
    size_t const minInputSize = ZSTD_startingInputLength(format);
    RETURN_ERROR_IF(srcSize < minInputSize, srcSize_wrong, "");

    {   BYTE const fhd = ((const BYTE*)src)[minInputSize-1];
        U32 const dictID= fhd & 3;
        U32 const singleSegment = (fhd >> 5) & 1;
        U32 const fcsId = fhd >> 6;
        return minInputSize + !singleSegment
             + ZSTD_did_fieldSize[dictID] + ZSTD_fcs_fieldSize[fcsId]
             + (singleSegment && !fcsId);
    }
}

/** ZSTD_frameHeaderSize() :
 *  srcSize must be >= ZSTD_frameHeaderSize_prefix.
 * @return : size of the Frame Header,
 *           or an error code (if srcSize is too small) */
size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize)
{
    return ZSTD_frameHeaderSize_internal(src, srcSize, ZSTD_f_zstd1);
}


/** ZSTD_getFrameHeader_advanced() :
 *  decode Frame Header, or require larger `srcSize`.
 *  note : only works for formats ZSTD_f_zstd1 and ZSTD_f_zstd1_magicless
 * @return : 0, `zfhPtr` is correctly filled,
 *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
**           or an error code, which can be tested using ZSTD_isError() */
size_t ZSTD_getFrameHeader_advanced(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize, ZSTD_format_e format)
{
    const BYTE* ip = (const BYTE*)src;
    size_t const minInputSize = ZSTD_startingInputLength(format);

    DEBUGLOG(5, "ZSTD_getFrameHeader_advanced: minInputSize = %zu, srcSize = %zu", minInputSize, srcSize);

    if (srcSize > 0) {
        /* note : technically could be considered an assert(), since it's an invalid entry */
        RETURN_ERROR_IF(src==NULL, GENERIC, "invalid parameter : src==NULL, but srcSize>0");
    }
    if (srcSize < minInputSize) {
        if (srcSize > 0 && format != ZSTD_f_zstd1_magicless) {
            /* when receiving less than @minInputSize bytes,
             * control these bytes at least correspond to a supported magic number
             * in order to error out early if they don't.
            **/
            size_t const toCopy = MIN(4, srcSize);
            unsigned char hbuf[4]; MEM_writeLE32(hbuf, ZSTD_MAGICNUMBER);
            assert(src != NULL);
            ZSTD_memcpy(hbuf, src, toCopy);
            if ( MEM_readLE32(hbuf) != ZSTD_MAGICNUMBER ) {
                /* not a zstd frame : let's check if it's a skippable frame */
                MEM_writeLE32(hbuf, ZSTD_MAGIC_SKIPPABLE_START);
                ZSTD_memcpy(hbuf, src, toCopy);
                if ((MEM_readLE32(hbuf) & ZSTD_MAGIC_SKIPPABLE_MASK) != ZSTD_MAGIC_SKIPPABLE_START) {
                    RETURN_ERROR(prefix_unknown,
                                "first bytes don't correspond to any supported magic number");
        }   }   }
        return minInputSize;
    }

    ZSTD_memset(zfhPtr, 0, sizeof(*zfhPtr));   /* not strictly necessary, but static analyzers may not understand that zfhPtr will be read only if return value is zero, since they are 2 different signals */
    if ( (format != ZSTD_f_zstd1_magicless)
      && (MEM_readLE32(src) != ZSTD_MAGICNUMBER) ) {
        if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
            /* skippable frame */
            if (srcSize < ZSTD_SKIPPABLEHEADERSIZE)
                return ZSTD_SKIPPABLEHEADERSIZE; /* magic number + frame length */
            ZSTD_memset(zfhPtr, 0, sizeof(*zfhPtr));
            zfhPtr->frameContentSize = MEM_readLE32((const char *)src + ZSTD_FRAMEIDSIZE);
            zfhPtr->frameType = ZSTD_skippableFrame;
            return 0;
        }
        RETURN_ERROR(prefix_unknown, "");
    }

    /* ensure there is enough `srcSize` to fully read/decode frame header */
    {   size_t const fhsize = ZSTD_frameHeaderSize_internal(src, srcSize, format);
        if (srcSize < fhsize) return fhsize;
        zfhPtr->headerSize = (U32)fhsize;
    }

    {   BYTE const fhdByte = ip[minInputSize-1];
        size_t pos = minInputSize;
        U32 const dictIDSizeCode = fhdByte&3;
        U32 const checksumFlag = (fhdByte>>2)&1;
        U32 const singleSegment = (fhdByte>>5)&1;
        U32 const fcsID = fhdByte>>6;
        U64 windowSize = 0;
        U32 dictID = 0;
        U64 frameContentSize = ZSTD_CONTENTSIZE_UNKNOWN;
        RETURN_ERROR_IF((fhdByte & 0x08) != 0, frameParameter_unsupported,
                        "reserved bits, must be zero");

        if (!singleSegment) {
            BYTE const wlByte = ip[pos++];
            U32 const windowLog = (wlByte >> 3) + ZSTD_WINDOWLOG_ABSOLUTEMIN;
            RETURN_ERROR_IF(windowLog > ZSTD_WINDOWLOG_MAX, frameParameter_windowTooLarge, "");
            windowSize = (1ULL << windowLog);
            windowSize += (windowSize >> 3) * (wlByte&7);
        }
        switch(dictIDSizeCode)
        {
            default:
                assert(0);  /* impossible */
                ZSTD_FALLTHROUGH;
            case 0 : break;
            case 1 : dictID = ip[pos]; pos++; break;
            case 2 : dictID = MEM_readLE16(ip+pos); pos+=2; break;
            case 3 : dictID = MEM_readLE32(ip+pos); pos+=4; break;
        }
        switch(fcsID)
        {
            default:
                assert(0);  /* impossible */
                ZSTD_FALLTHROUGH;
            case 0 : if (singleSegment) frameContentSize = ip[pos]; break;
            case 1 : frameContentSize = MEM_readLE16(ip+pos)+256; break;
            case 2 : frameContentSize = MEM_readLE32(ip+pos); break;
            case 3 : frameContentSize = MEM_readLE64(ip+pos); break;
        }
        if (singleSegment) windowSize = frameContentSize;

        zfhPtr->frameType = ZSTD_frame;
        zfhPtr->frameContentSize = frameContentSize;
        zfhPtr->windowSize = windowSize;
        zfhPtr->blockSizeMax = (unsigned) MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
        zfhPtr->dictID = dictID;
        zfhPtr->checksumFlag = checksumFlag;
    }
    return 0;
}

/** ZSTD_getFrameHeader() :
 *  decode Frame Header, or require larger `srcSize`.
 *  note : this function does not consume input, it only reads it.
 * @return : 0, `zfhPtr` is correctly filled,
 *          >0, `srcSize` is too small, value is wanted `srcSize` amount,
 *           or an error code, which can be tested using ZSTD_isError() */
size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize)
{
    return ZSTD_getFrameHeader_advanced(zfhPtr, src, srcSize, ZSTD_f_zstd1);
}

/** ZSTD_getFrameContentSize() :
 *  compatible with legacy mode
 * @return : decompressed size of the single frame pointed to be `src` if known, otherwise
 *         - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
 *         - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small) */
unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize)
{
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
    if (ZSTD_isLegacy(src, srcSize)) {
        unsigned long long const ret = ZSTD_getDecompressedSize_legacy(src, srcSize);
        return ret == 0 ? ZSTD_CONTENTSIZE_UNKNOWN : ret;
    }
#endif
    {   ZSTD_frameHeader zfh;
        if (ZSTD_getFrameHeader(&zfh, src, srcSize) != 0)
            return ZSTD_CONTENTSIZE_ERROR;
        if (zfh.frameType == ZSTD_skippableFrame) {
            return 0;
        } else {
            return zfh.frameContentSize;
    }   }
}

static size_t readSkippableFrameSize(void const* src, size_t srcSize)
{
    size_t const skippableHeaderSize = ZSTD_SKIPPABLEHEADERSIZE;
    U32 sizeU32;

    RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, "");

    sizeU32 = MEM_readLE32((BYTE const*)src + ZSTD_FRAMEIDSIZE);
    RETURN_ERROR_IF((U32)(sizeU32 + ZSTD_SKIPPABLEHEADERSIZE) < sizeU32,
                    frameParameter_unsupported, "");
    {   size_t const skippableSize = skippableHeaderSize + sizeU32;
        RETURN_ERROR_IF(skippableSize > srcSize, srcSize_wrong, "");
        return skippableSize;
    }
}

/*! ZSTD_readSkippableFrame() :
 * Retrieves content of a skippable frame, and writes it to dst buffer.
 *
 * The parameter magicVariant will receive the magicVariant that was supplied when the frame was written,
 * i.e. magicNumber - ZSTD_MAGIC_SKIPPABLE_START.  This can be NULL if the caller is not interested
 * in the magicVariant.
 *
 * Returns an error if destination buffer is not large enough, or if this is not a valid skippable frame.
 *
 * @return : number of bytes written or a ZSTD error.
 */
size_t ZSTD_readSkippableFrame(void* dst, size_t dstCapacity,
                               unsigned* magicVariant,  /* optional, can be NULL */
                         const void* src, size_t srcSize)
{
    RETURN_ERROR_IF(srcSize < ZSTD_SKIPPABLEHEADERSIZE, srcSize_wrong, "");

    {   U32 const magicNumber = MEM_readLE32(src);
        size_t skippableFrameSize = readSkippableFrameSize(src, srcSize);
        size_t skippableContentSize = skippableFrameSize - ZSTD_SKIPPABLEHEADERSIZE;

        /* check input validity */
        RETURN_ERROR_IF(!ZSTD_isSkippableFrame(src, srcSize), frameParameter_unsupported, "");
        RETURN_ERROR_IF(skippableFrameSize < ZSTD_SKIPPABLEHEADERSIZE || skippableFrameSize > srcSize, srcSize_wrong, "");
        RETURN_ERROR_IF(skippableContentSize > dstCapacity, dstSize_tooSmall, "");

        /* deliver payload */
        if (skippableContentSize > 0  && dst != NULL)
            ZSTD_memcpy(dst, (const BYTE *)src + ZSTD_SKIPPABLEHEADERSIZE, skippableContentSize);
        if (magicVariant != NULL)
            *magicVariant = magicNumber - ZSTD_MAGIC_SKIPPABLE_START;
        return skippableContentSize;
    }
}

/** ZSTD_findDecompressedSize() :
 *  `srcSize` must be the exact length of some number of ZSTD compressed and/or
 *      skippable frames
 *  note: compatible with legacy mode
 * @return : decompressed size of the frames contained */
unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize)
{
    unsigned long long totalDstSize = 0;

    while (srcSize >= ZSTD_startingInputLength(ZSTD_f_zstd1)) {
        U32 const magicNumber = MEM_readLE32(src);

        if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
            size_t const skippableSize = readSkippableFrameSize(src, srcSize);
            if (ZSTD_isError(skippableSize)) return ZSTD_CONTENTSIZE_ERROR;
            assert(skippableSize <= srcSize);

            src = (const BYTE *)src + skippableSize;
            srcSize -= skippableSize;
            continue;
        }

        {   unsigned long long const fcs = ZSTD_getFrameContentSize(src, srcSize);
            if (fcs >= ZSTD_CONTENTSIZE_ERROR) return fcs;

            if (totalDstSize + fcs < totalDstSize)
                return ZSTD_CONTENTSIZE_ERROR; /* check for overflow */
            totalDstSize += fcs;
        }
        /* skip to next frame */
        {   size_t const frameSrcSize = ZSTD_findFrameCompressedSize(src, srcSize);
            if (ZSTD_isError(frameSrcSize)) return ZSTD_CONTENTSIZE_ERROR;
            assert(frameSrcSize <= srcSize);

            src = (const BYTE *)src + frameSrcSize;
            srcSize -= frameSrcSize;
        }
    }  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */

    if (srcSize) return ZSTD_CONTENTSIZE_ERROR;

    return totalDstSize;
}

/** ZSTD_getDecompressedSize() :
 *  compatible with legacy mode
 * @return : decompressed size if known, 0 otherwise
             note : 0 can mean any of the following :
                   - frame content is empty
                   - decompressed size field is not present in frame header
                   - frame header unknown / not supported
                   - frame header not complete (`srcSize` too small) */
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize)
{
    unsigned long long const ret = ZSTD_getFrameContentSize(src, srcSize);
    ZSTD_STATIC_ASSERT(ZSTD_CONTENTSIZE_ERROR < ZSTD_CONTENTSIZE_UNKNOWN);
    return (ret >= ZSTD_CONTENTSIZE_ERROR) ? 0 : ret;
}


/** ZSTD_decodeFrameHeader() :
 * `headerSize` must be the size provided by ZSTD_frameHeaderSize().
 * If multiple DDict references are enabled, also will choose the correct DDict to use.
 * @return : 0 if success, or an error code, which can be tested using ZSTD_isError() */
static size_t ZSTD_decodeFrameHeader(ZSTD_DCtx* dctx, const void* src, size_t headerSize)
{
    size_t const result = ZSTD_getFrameHeader_advanced(&(dctx->fParams), src, headerSize, dctx->format);
    if (ZSTD_isError(result)) return result;    /* invalid header */
    RETURN_ERROR_IF(result>0, srcSize_wrong, "headerSize too small");

    /* Reference DDict requested by frame if dctx references multiple ddicts */
    if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts && dctx->ddictSet) {
        ZSTD_DCtx_selectFrameDDict(dctx);
    }

#ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
    /* Skip the dictID check in fuzzing mode, because it makes the search
     * harder.
     */
    RETURN_ERROR_IF(dctx->fParams.dictID && (dctx->dictID != dctx->fParams.dictID),
                    dictionary_wrong, "");
#endif
    dctx->validateChecksum = (dctx->fParams.checksumFlag && !dctx->forceIgnoreChecksum) ? 1 : 0;
    if (dctx->validateChecksum) XXH64_reset(&dctx->xxhState, 0);
    dctx->processedCSize += headerSize;
    return 0;
}

static ZSTD_frameSizeInfo ZSTD_errorFrameSizeInfo(size_t ret)
{
    ZSTD_frameSizeInfo frameSizeInfo;
    frameSizeInfo.compressedSize = ret;
    frameSizeInfo.decompressedBound = ZSTD_CONTENTSIZE_ERROR;
    return frameSizeInfo;
}

static ZSTD_frameSizeInfo ZSTD_findFrameSizeInfo(const void* src, size_t srcSize, ZSTD_format_e format)
{
    ZSTD_frameSizeInfo frameSizeInfo;
    ZSTD_memset(&frameSizeInfo, 0, sizeof(ZSTD_frameSizeInfo));

#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
    if (format == ZSTD_f_zstd1 && ZSTD_isLegacy(src, srcSize))
        return ZSTD_findFrameSizeInfoLegacy(src, srcSize);
#endif

    if (format == ZSTD_f_zstd1 && (srcSize >= ZSTD_SKIPPABLEHEADERSIZE)
        && (MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
        frameSizeInfo.compressedSize = readSkippableFrameSize(src, srcSize);
        assert(ZSTD_isError(frameSizeInfo.compressedSize) ||
               frameSizeInfo.compressedSize <= srcSize);
        return frameSizeInfo;
    } else {
        const BYTE* ip = (const BYTE*)src;
        const BYTE* const ipstart = ip;
        size_t remainingSize = srcSize;
        size_t nbBlocks = 0;
        ZSTD_frameHeader zfh;

        /* Extract Frame Header */
        {   size_t const ret = ZSTD_getFrameHeader_advanced(&zfh, src, srcSize, format);
            if (ZSTD_isError(ret))
                return ZSTD_errorFrameSizeInfo(ret);
            if (ret > 0)
                return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
        }

        ip += zfh.headerSize;
        remainingSize -= zfh.headerSize;

        /* Iterate over each block */
        while (1) {
            blockProperties_t blockProperties;
            size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSize, &blockProperties);
            if (ZSTD_isError(cBlockSize))
                return ZSTD_errorFrameSizeInfo(cBlockSize);

            if (ZSTD_blockHeaderSize + cBlockSize > remainingSize)
                return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));

            ip += ZSTD_blockHeaderSize + cBlockSize;
            remainingSize -= ZSTD_blockHeaderSize + cBlockSize;
            nbBlocks++;

            if (blockProperties.lastBlock) break;
        }

        /* Final frame content checksum */
        if (zfh.checksumFlag) {
            if (remainingSize < 4)
                return ZSTD_errorFrameSizeInfo(ERROR(srcSize_wrong));
            ip += 4;
        }

        frameSizeInfo.nbBlocks = nbBlocks;
        frameSizeInfo.compressedSize = (size_t)(ip - ipstart);
        frameSizeInfo.decompressedBound = (zfh.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN)
                                        ? zfh.frameContentSize
                                        : (unsigned long long)nbBlocks * zfh.blockSizeMax;
        return frameSizeInfo;
    }
}

static size_t ZSTD_findFrameCompressedSize_advanced(const void *src, size_t srcSize, ZSTD_format_e format) {
    ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize, format);
    return frameSizeInfo.compressedSize;
}

/** ZSTD_findFrameCompressedSize() :
 * See docs in zstd.h
 * Note: compatible with legacy mode */
size_t ZSTD_findFrameCompressedSize(const void *src, size_t srcSize)
{
    return ZSTD_findFrameCompressedSize_advanced(src, srcSize, ZSTD_f_zstd1);
}

/** ZSTD_decompressBound() :
 *  compatible with legacy mode
 *  `src` must point to the start of a ZSTD frame or a skippeable frame
 *  `srcSize` must be at least as large as the frame contained
 *  @return : the maximum decompressed size of the compressed source
 */
unsigned long long ZSTD_decompressBound(const void* src, size_t srcSize)
{
    unsigned long long bound = 0;
    /* Iterate over each frame */
    while (srcSize > 0) {
        ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize, ZSTD_f_zstd1);
        size_t const compressedSize = frameSizeInfo.compressedSize;
        unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
        if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
            return ZSTD_CONTENTSIZE_ERROR;
        assert(srcSize >= compressedSize);
        src = (const BYTE*)src + compressedSize;
        srcSize -= compressedSize;
        bound += decompressedBound;
    }
    return bound;
}

size_t ZSTD_decompressionMargin(void const* src, size_t srcSize)
{
    size_t margin = 0;
    unsigned maxBlockSize = 0;

    /* Iterate over each frame */
    while (srcSize > 0) {
        ZSTD_frameSizeInfo const frameSizeInfo = ZSTD_findFrameSizeInfo(src, srcSize, ZSTD_f_zstd1);
        size_t const compressedSize = frameSizeInfo.compressedSize;
        unsigned long long const decompressedBound = frameSizeInfo.decompressedBound;
        ZSTD_frameHeader zfh;

        FORWARD_IF_ERROR(ZSTD_getFrameHeader(&zfh, src, srcSize), "");
        if (ZSTD_isError(compressedSize) || decompressedBound == ZSTD_CONTENTSIZE_ERROR)
            return ERROR(corruption_detected);

        if (zfh.frameType == ZSTD_frame) {
            /* Add the frame header to our margin */
            margin += zfh.headerSize;
            /* Add the checksum to our margin */
            margin += zfh.checksumFlag ? 4 : 0;
            /* Add 3 bytes per block */
            margin += 3 * frameSizeInfo.nbBlocks;

            /* Compute the max block size */
            maxBlockSize = MAX(maxBlockSize, zfh.blockSizeMax);
        } else {
            assert(zfh.frameType == ZSTD_skippableFrame);
            /* Add the entire skippable frame size to our margin. */
            margin += compressedSize;
        }

        assert(srcSize >= compressedSize);
        src = (const BYTE*)src + compressedSize;
        srcSize -= compressedSize;
    }

    /* Add the max block size back to the margin. */
    margin += maxBlockSize;

    return margin;
}

/*-*************************************************************
 *   Frame decoding
 ***************************************************************/

/** ZSTD_insertBlock() :
 *  insert `src` block into `dctx` history. Useful to track uncompressed blocks. */
size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize)
{
    DEBUGLOG(5, "ZSTD_insertBlock: %u bytes", (unsigned)blockSize);
    ZSTD_checkContinuity(dctx, blockStart, blockSize);
    dctx->previousDstEnd = (const char*)blockStart + blockSize;
    return blockSize;
}


static size_t ZSTD_copyRawBlock(void* dst, size_t dstCapacity,
                          const void* src, size_t srcSize)
{
    DEBUGLOG(5, "ZSTD_copyRawBlock");
    RETURN_ERROR_IF(srcSize > dstCapacity, dstSize_tooSmall, "");
    if (dst == NULL) {
        if (srcSize == 0) return 0;
        RETURN_ERROR(dstBuffer_null, "");
    }
    ZSTD_memmove(dst, src, srcSize);
    return srcSize;
}

static size_t ZSTD_setRleBlock(void* dst, size_t dstCapacity,
                               BYTE b,
                               size_t regenSize)
{
    RETURN_ERROR_IF(regenSize > dstCapacity, dstSize_tooSmall, "");
    if (dst == NULL) {
        if (regenSize == 0) return 0;
        RETURN_ERROR(dstBuffer_null, "");
    }
    ZSTD_memset(dst, b, regenSize);
    return regenSize;
}

static void ZSTD_DCtx_trace_end(ZSTD_DCtx const* dctx, U64 uncompressedSize, U64 compressedSize, unsigned streaming)
{
#if ZSTD_TRACE
    if (dctx->traceCtx && ZSTD_trace_decompress_end != NULL) {
        ZSTD_Trace trace;
        ZSTD_memset(&trace, 0, sizeof(trace));
        trace.version = ZSTD_VERSION_NUMBER;
        trace.streaming = streaming;
        if (dctx->ddict) {
            trace.dictionaryID = ZSTD_getDictID_fromDDict(dctx->ddict);
            trace.dictionarySize = ZSTD_DDict_dictSize(dctx->ddict);
            trace.dictionaryIsCold = dctx->ddictIsCold;
        }
        trace.uncompressedSize = (size_t)uncompressedSize;
        trace.compressedSize = (size_t)compressedSize;
        trace.dctx = dctx;
        ZSTD_trace_decompress_end(dctx->traceCtx, &trace);
    }
#else
    (void)dctx;
    (void)uncompressedSize;
    (void)compressedSize;
    (void)streaming;
#endif
}


/*! ZSTD_decompressFrame() :
 * @dctx must be properly initialized
 *  will update *srcPtr and *srcSizePtr,
 *  to make *srcPtr progress by one frame. */
static size_t ZSTD_decompressFrame(ZSTD_DCtx* dctx,
                                   void* dst, size_t dstCapacity,
                             const void** srcPtr, size_t *srcSizePtr)
{
    const BYTE* const istart = (const BYTE*)(*srcPtr);
    const BYTE* ip = istart;
    BYTE* const ostart = (BYTE*)dst;
    BYTE* const oend = dstCapacity != 0 ? ostart + dstCapacity : ostart;
    BYTE* op = ostart;
    size_t remainingSrcSize = *srcSizePtr;

    DEBUGLOG(4, "ZSTD_decompressFrame (srcSize:%i)", (int)*srcSizePtr);

    /* check */
    RETURN_ERROR_IF(
        remainingSrcSize < ZSTD_FRAMEHEADERSIZE_MIN(dctx->format)+ZSTD_blockHeaderSize,
        srcSize_wrong, "");

    /* Frame Header */
    {   size_t const frameHeaderSize = ZSTD_frameHeaderSize_internal(
                ip, ZSTD_FRAMEHEADERSIZE_PREFIX(dctx->format), dctx->format);
        if (ZSTD_isError(frameHeaderSize)) return frameHeaderSize;
        RETURN_ERROR_IF(remainingSrcSize < frameHeaderSize+ZSTD_blockHeaderSize,
                        srcSize_wrong, "");
        FORWARD_IF_ERROR( ZSTD_decodeFrameHeader(dctx, ip, frameHeaderSize) , "");
        ip += frameHeaderSize; remainingSrcSize -= frameHeaderSize;
    }

    /* Shrink the blockSizeMax if enabled */
    if (dctx->maxBlockSizeParam != 0)
        dctx->fParams.blockSizeMax = MIN(dctx->fParams.blockSizeMax, (unsigned)dctx->maxBlockSizeParam);

    /* Loop on each block */
    while (1) {
        BYTE* oBlockEnd = oend;
        size_t decodedSize;
        blockProperties_t blockProperties;
        size_t const cBlockSize = ZSTD_getcBlockSize(ip, remainingSrcSize, &blockProperties);
        if (ZSTD_isError(cBlockSize)) return cBlockSize;

        ip += ZSTD_blockHeaderSize;
        remainingSrcSize -= ZSTD_blockHeaderSize;
        RETURN_ERROR_IF(cBlockSize > remainingSrcSize, srcSize_wrong, "");

        if (ip >= op && ip < oBlockEnd) {
            /* We are decompressing in-place. Limit the output pointer so that we
             * don't overwrite the block that we are currently reading. This will
             * fail decompression if the input & output pointers aren't spaced
             * far enough apart.
             *
             * This is important to set, even when the pointers are far enough
             * apart, because ZSTD_decompressBlock_internal() can decide to store
             * literals in the output buffer, after the block it is decompressing.
             * Since we don't want anything to overwrite our input, we have to tell
             * ZSTD_decompressBlock_internal to never write past ip.
             *
             * See ZSTD_allocateLiteralsBuffer() for reference.
             */
            oBlockEnd = op + (ip - op);
        }

        switch(blockProperties.blockType)
        {
        case bt_compressed:
            assert(dctx->isFrameDecompression == 1);
            decodedSize = ZSTD_decompressBlock_internal(dctx, op, (size_t)(oBlockEnd-op), ip, cBlockSize, not_streaming);
            break;
        case bt_raw :
            /* Use oend instead of oBlockEnd because this function is safe to overlap. It uses memmove. */
            decodedSize = ZSTD_copyRawBlock(op, (size_t)(oend-op), ip, cBlockSize);
            break;
        case bt_rle :
            decodedSize = ZSTD_setRleBlock(op, (size_t)(oBlockEnd-op), *ip, blockProperties.origSize);
            break;
        case bt_reserved :
        default:
            RETURN_ERROR(corruption_detected, "invalid block type");
        }
        FORWARD_IF_ERROR(decodedSize, "Block decompression failure");
        DEBUGLOG(5, "Decompressed block of dSize = %u", (unsigned)decodedSize);
        if (dctx->validateChecksum) {
            XXH64_update(&dctx->xxhState, op, decodedSize);
        }
        if (decodedSize) /* support dst = NULL,0 */ {
            op += decodedSize;
        }
        assert(ip != NULL);
        ip += cBlockSize;
        remainingSrcSize -= cBlockSize;
        if (blockProperties.lastBlock) break;
    }

    if (dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN) {
        RETURN_ERROR_IF((U64)(op-ostart) != dctx->fParams.frameContentSize,
                        corruption_detected, "");
    }
    if (dctx->fParams.checksumFlag) { /* Frame content checksum verification */
        RETURN_ERROR_IF(remainingSrcSize<4, checksum_wrong, "");
        if (!dctx->forceIgnoreChecksum) {
            U32 const checkCalc = (U32)XXH64_digest(&dctx->xxhState);
            U32 checkRead;
            checkRead = MEM_readLE32(ip);
            RETURN_ERROR_IF(checkRead != checkCalc, checksum_wrong, "");
        }
        ip += 4;
        remainingSrcSize -= 4;
    }
    ZSTD_DCtx_trace_end(dctx, (U64)(op-ostart), (U64)(ip-istart), /* streaming */ 0);
    /* Allow caller to get size read */
    DEBUGLOG(4, "ZSTD_decompressFrame: decompressed frame of size %zi, consuming %zi bytes of input", op-ostart, ip - (const BYTE*)*srcPtr);
    *srcPtr = ip;
    *srcSizePtr = remainingSrcSize;
    return (size_t)(op-ostart);
}

static
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
size_t ZSTD_decompressMultiFrame(ZSTD_DCtx* dctx,
                                        void* dst, size_t dstCapacity,
                                  const void* src, size_t srcSize,
                                  const void* dict, size_t dictSize,
                                  const ZSTD_DDict* ddict)
{
    void* const dststart = dst;
    int moreThan1Frame = 0;

    DEBUGLOG(5, "ZSTD_decompressMultiFrame");
    assert(dict==NULL || ddict==NULL);  /* either dict or ddict set, not both */

    if (ddict) {
        dict = ZSTD_DDict_dictContent(ddict);
        dictSize = ZSTD_DDict_dictSize(ddict);
    }

    while (srcSize >= ZSTD_startingInputLength(dctx->format)) {

#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT >= 1)
        if (dctx->format == ZSTD_f_zstd1 && ZSTD_isLegacy(src, srcSize)) {
            size_t decodedSize;
            size_t const frameSize = ZSTD_findFrameCompressedSizeLegacy(src, srcSize);
            if (ZSTD_isError(frameSize)) return frameSize;
            RETURN_ERROR_IF(dctx->staticSize, memory_allocation,
                "legacy support is not compatible with static dctx");

            decodedSize = ZSTD_decompressLegacy(dst, dstCapacity, src, frameSize, dict, dictSize);
            if (ZSTD_isError(decodedSize)) return decodedSize;

            {
                unsigned long long const expectedSize = ZSTD_getFrameContentSize(src, srcSize);
                RETURN_ERROR_IF(expectedSize == ZSTD_CONTENTSIZE_ERROR, corruption_detected, "Corrupted frame header!");
                if (expectedSize != ZSTD_CONTENTSIZE_UNKNOWN) {
                    RETURN_ERROR_IF(expectedSize != decodedSize, corruption_detected,
                        "Frame header size does not match decoded size!");
                }
            }

            assert(decodedSize <= dstCapacity);
            dst = (BYTE*)dst + decodedSize;
            dstCapacity -= decodedSize;

            src = (const BYTE*)src + frameSize;
            srcSize -= frameSize;

            continue;
        }
#endif

        if (dctx->format == ZSTD_f_zstd1 && srcSize >= 4) {
            U32 const magicNumber = MEM_readLE32(src);
            DEBUGLOG(5, "reading magic number %08X", (unsigned)magicNumber);
            if ((magicNumber & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {
                /* skippable frame detected : skip it */
                size_t const skippableSize = readSkippableFrameSize(src, srcSize);
                FORWARD_IF_ERROR(skippableSize, "invalid skippable frame");
                assert(skippableSize <= srcSize);

                src = (const BYTE *)src + skippableSize;
                srcSize -= skippableSize;
                continue; /* check next frame */
        }   }

        if (ddict) {
            /* we were called from ZSTD_decompress_usingDDict */
            FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(dctx, ddict), "");
        } else {
            /* this will initialize correctly with no dict if dict == NULL, so
             * use this in all cases but ddict */
            FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDict(dctx, dict, dictSize), "");
        }
        ZSTD_checkContinuity(dctx, dst, dstCapacity);

        {   const size_t res = ZSTD_decompressFrame(dctx, dst, dstCapacity,
                                                    &src, &srcSize);
            RETURN_ERROR_IF(
                (ZSTD_getErrorCode(res) == ZSTD_error_prefix_unknown)
             && (moreThan1Frame==1),
                srcSize_wrong,
                "At least one frame successfully completed, "
                "but following bytes are garbage: "
                "it's more likely to be a srcSize error, "
                "specifying more input bytes than size of frame(s). "
                "Note: one could be unlucky, it might be a corruption error instead, "
                "happening right at the place where we expect zstd magic bytes. "
                "But this is _much_ less likely than a srcSize field error.");
            if (ZSTD_isError(res)) return res;
            assert(res <= dstCapacity);
            if (res != 0)
                dst = (BYTE*)dst + res;
            dstCapacity -= res;
        }
        moreThan1Frame = 1;
    }  /* while (srcSize >= ZSTD_frameHeaderSize_prefix) */

    RETURN_ERROR_IF(srcSize, srcSize_wrong, "input not entirely consumed");

    return (size_t)((BYTE*)dst - (BYTE*)dststart);
}

size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
                                 void* dst, size_t dstCapacity,
                           const void* src, size_t srcSize,
                           const void* dict, size_t dictSize)
{
    return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize, dict, dictSize, NULL);
}


static ZSTD_DDict const* ZSTD_getDDict(ZSTD_DCtx* dctx)
{
    switch (dctx->dictUses) {
    default:
        assert(0 /* Impossible */);
        ZSTD_FALLTHROUGH;
    case ZSTD_dont_use:
        ZSTD_clearDict(dctx);
        return NULL;
    case ZSTD_use_indefinitely:
        return dctx->ddict;
    case ZSTD_use_once:
        dctx->dictUses = ZSTD_dont_use;
        return dctx->ddict;
    }
}

size_t ZSTD_decompressDCtx(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
    return ZSTD_decompress_usingDDict(dctx, dst, dstCapacity, src, srcSize, ZSTD_getDDict(dctx));
}


size_t ZSTD_decompress(void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
#if defined(ZSTD_HEAPMODE) && (ZSTD_HEAPMODE>=1)
    size_t regenSize;
    ZSTD_DCtx* const dctx =  ZSTD_createDCtx_internal(ZSTD_defaultCMem);
    RETURN_ERROR_IF(dctx==NULL, memory_allocation, "NULL pointer!");
    regenSize = ZSTD_decompressDCtx(dctx, dst, dstCapacity, src, srcSize);
    ZSTD_freeDCtx(dctx);
    return regenSize;
#else   /* stack mode */
    ZSTD_DCtx dctx;
    ZSTD_initDCtx_internal(&dctx);
    return ZSTD_decompressDCtx(&dctx, dst, dstCapacity, src, srcSize);
#endif
}


/*-**************************************
*   Advanced Streaming Decompression API
*   Bufferless and synchronous
****************************************/
size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx) { return dctx->expected; }

/**
 * Similar to ZSTD_nextSrcSizeToDecompress(), but when a block input can be streamed, we
 * allow taking a partial block as the input. Currently only raw uncompressed blocks can
 * be streamed.
 *
 * For blocks that can be streamed, this allows us to reduce the latency until we produce
 * output, and avoid copying the input.
 *
 * @param inputSize - The total amount of input that the caller currently has.
 */
static size_t ZSTD_nextSrcSizeToDecompressWithInputSize(ZSTD_DCtx* dctx, size_t inputSize) {
    if (!(dctx->stage == ZSTDds_decompressBlock || dctx->stage == ZSTDds_decompressLastBlock))
        return dctx->expected;
    if (dctx->bType != bt_raw)
        return dctx->expected;
    return BOUNDED(1, inputSize, dctx->expected);
}

ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx) {
    switch(dctx->stage)
    {
    default:   /* should not happen */
        assert(0);
        ZSTD_FALLTHROUGH;
    case ZSTDds_getFrameHeaderSize:
        ZSTD_FALLTHROUGH;
    case ZSTDds_decodeFrameHeader:
        return ZSTDnit_frameHeader;
    case ZSTDds_decodeBlockHeader:
        return ZSTDnit_blockHeader;
    case ZSTDds_decompressBlock:
        return ZSTDnit_block;
    case ZSTDds_decompressLastBlock:
        return ZSTDnit_lastBlock;
    case ZSTDds_checkChecksum:
        return ZSTDnit_checksum;
    case ZSTDds_decodeSkippableHeader:
        ZSTD_FALLTHROUGH;
    case ZSTDds_skipFrame:
        return ZSTDnit_skippableFrame;
    }
}

static int ZSTD_isSkipFrame(ZSTD_DCtx* dctx) { return dctx->stage == ZSTDds_skipFrame; }

/** ZSTD_decompressContinue() :
 *  srcSize : must be the exact nb of bytes expected (see ZSTD_nextSrcSizeToDecompress())
 *  @return : nb of bytes generated into `dst` (necessarily <= `dstCapacity)
 *            or an error code, which can be tested using ZSTD_isError() */
size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize)
{
    DEBUGLOG(5, "ZSTD_decompressContinue (srcSize:%u)", (unsigned)srcSize);
    /* Sanity check */
    RETURN_ERROR_IF(srcSize != ZSTD_nextSrcSizeToDecompressWithInputSize(dctx, srcSize), srcSize_wrong, "not allowed");
    ZSTD_checkContinuity(dctx, dst, dstCapacity);

    dctx->processedCSize += srcSize;

    switch (dctx->stage)
    {
    case ZSTDds_getFrameHeaderSize :
        assert(src != NULL);
        if (dctx->format == ZSTD_f_zstd1) {  /* allows header */
            assert(srcSize >= ZSTD_FRAMEIDSIZE);  /* to read skippable magic number */
            if ((MEM_readLE32(src) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {        /* skippable frame */
                ZSTD_memcpy(dctx->headerBuffer, src, srcSize);
                dctx->expected = ZSTD_SKIPPABLEHEADERSIZE - srcSize;  /* remaining to load to get full skippable frame header */
                dctx->stage = ZSTDds_decodeSkippableHeader;
                return 0;
        }   }
        dctx->headerSize = ZSTD_frameHeaderSize_internal(src, srcSize, dctx->format);
        if (ZSTD_isError(dctx->headerSize)) return dctx->headerSize;
        ZSTD_memcpy(dctx->headerBuffer, src, srcSize);
        dctx->expected = dctx->headerSize - srcSize;
        dctx->stage = ZSTDds_decodeFrameHeader;
        return 0;

    case ZSTDds_decodeFrameHeader:
        assert(src != NULL);
        ZSTD_memcpy(dctx->headerBuffer + (dctx->headerSize - srcSize), src, srcSize);
        FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(dctx, dctx->headerBuffer, dctx->headerSize), "");
        dctx->expected = ZSTD_blockHeaderSize;
        dctx->stage = ZSTDds_decodeBlockHeader;
        return 0;

    case ZSTDds_decodeBlockHeader:
        {   blockProperties_t bp;
            size_t const cBlockSize = ZSTD_getcBlockSize(src, ZSTD_blockHeaderSize, &bp);
            if (ZSTD_isError(cBlockSize)) return cBlockSize;
            RETURN_ERROR_IF(cBlockSize > dctx->fParams.blockSizeMax, corruption_detected, "Block Size Exceeds Maximum");
            dctx->expected = cBlockSize;
            dctx->bType = bp.blockType;
            dctx->rleSize = bp.origSize;
            if (cBlockSize) {
                dctx->stage = bp.lastBlock ? ZSTDds_decompressLastBlock : ZSTDds_decompressBlock;
                return 0;
            }
            /* empty block */
            if (bp.lastBlock) {
                if (dctx->fParams.checksumFlag) {
                    dctx->expected = 4;
                    dctx->stage = ZSTDds_checkChecksum;
                } else {
                    dctx->expected = 0; /* end of frame */
                    dctx->stage = ZSTDds_getFrameHeaderSize;
                }
            } else {
                dctx->expected = ZSTD_blockHeaderSize;  /* jump to next header */
                dctx->stage = ZSTDds_decodeBlockHeader;
            }
            return 0;
        }

    case ZSTDds_decompressLastBlock:
    case ZSTDds_decompressBlock:
        DEBUGLOG(5, "ZSTD_decompressContinue: case ZSTDds_decompressBlock");
        {   size_t rSize;
            switch(dctx->bType)
            {
            case bt_compressed:
                DEBUGLOG(5, "ZSTD_decompressContinue: case bt_compressed");
                assert(dctx->isFrameDecompression == 1);
                rSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, is_streaming);
                dctx->expected = 0;  /* Streaming not supported */
                break;
            case bt_raw :
                assert(srcSize <= dctx->expected);
                rSize = ZSTD_copyRawBlock(dst, dstCapacity, src, srcSize);
                FORWARD_IF_ERROR(rSize, "ZSTD_copyRawBlock failed");
                assert(rSize == srcSize);
                dctx->expected -= rSize;
                break;
            case bt_rle :
                rSize = ZSTD_setRleBlock(dst, dstCapacity, *(const BYTE*)src, dctx->rleSize);
                dctx->expected = 0;  /* Streaming not supported */
                break;
            case bt_reserved :   /* should never happen */
            default:
                RETURN_ERROR(corruption_detected, "invalid block type");
            }
            FORWARD_IF_ERROR(rSize, "");
            RETURN_ERROR_IF(rSize > dctx->fParams.blockSizeMax, corruption_detected, "Decompressed Block Size Exceeds Maximum");
            DEBUGLOG(5, "ZSTD_decompressContinue: decoded size from block : %u", (unsigned)rSize);
            dctx->decodedSize += rSize;
            if (dctx->validateChecksum) XXH64_update(&dctx->xxhState, dst, rSize);
            dctx->previousDstEnd = (char*)dst + rSize;

            /* Stay on the same stage until we are finished streaming the block. */
            if (dctx->expected > 0) {
                return rSize;
            }

            if (dctx->stage == ZSTDds_decompressLastBlock) {   /* end of frame */
                DEBUGLOG(4, "ZSTD_decompressContinue: decoded size from frame : %u", (unsigned)dctx->decodedSize);
                RETURN_ERROR_IF(
                    dctx->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
                 && dctx->decodedSize != dctx->fParams.frameContentSize,
                    corruption_detected, "");
                if (dctx->fParams.checksumFlag) {  /* another round for frame checksum */
                    dctx->expected = 4;
                    dctx->stage = ZSTDds_checkChecksum;
                } else {
                    ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1);
                    dctx->expected = 0;   /* ends here */
                    dctx->stage = ZSTDds_getFrameHeaderSize;
                }
            } else {
                dctx->stage = ZSTDds_decodeBlockHeader;
                dctx->expected = ZSTD_blockHeaderSize;
            }
            return rSize;
        }

    case ZSTDds_checkChecksum:
        assert(srcSize == 4);  /* guaranteed by dctx->expected */
        {
            if (dctx->validateChecksum) {
                U32 const h32 = (U32)XXH64_digest(&dctx->xxhState);
                U32 const check32 = MEM_readLE32(src);
                DEBUGLOG(4, "ZSTD_decompressContinue: checksum : calculated %08X :: %08X read", (unsigned)h32, (unsigned)check32);
                RETURN_ERROR_IF(check32 != h32, checksum_wrong, "");
            }
            ZSTD_DCtx_trace_end(dctx, dctx->decodedSize, dctx->processedCSize, /* streaming */ 1);
            dctx->expected = 0;
            dctx->stage = ZSTDds_getFrameHeaderSize;
            return 0;
        }

    case ZSTDds_decodeSkippableHeader:
        assert(src != NULL);
        assert(srcSize <= ZSTD_SKIPPABLEHEADERSIZE);
        assert(dctx->format != ZSTD_f_zstd1_magicless);
        ZSTD_memcpy(dctx->headerBuffer + (ZSTD_SKIPPABLEHEADERSIZE - srcSize), src, srcSize);   /* complete skippable header */
        dctx->expected = MEM_readLE32(dctx->headerBuffer + ZSTD_FRAMEIDSIZE);   /* note : dctx->expected can grow seriously large, beyond local buffer size */
        dctx->stage = ZSTDds_skipFrame;
        return 0;

    case ZSTDds_skipFrame:
        dctx->expected = 0;
        dctx->stage = ZSTDds_getFrameHeaderSize;
        return 0;

    default:
        assert(0);   /* impossible */
        RETURN_ERROR(GENERIC, "impossible to reach");   /* some compilers require default to do something */
    }
}


static size_t ZSTD_refDictContent(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
{
    dctx->dictEnd = dctx->previousDstEnd;
    dctx->virtualStart = (const char*)dict - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
    dctx->prefixStart = dict;
    dctx->previousDstEnd = (const char*)dict + dictSize;
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
    dctx->dictContentBeginForFuzzing = dctx->prefixStart;
    dctx->dictContentEndForFuzzing = dctx->previousDstEnd;
#endif
    return 0;
}

/*! ZSTD_loadDEntropy() :
 *  dict : must point at beginning of a valid zstd dictionary.
 * @return : size of entropy tables read */
size_t
ZSTD_loadDEntropy(ZSTD_entropyDTables_t* entropy,
                  const void* const dict, size_t const dictSize)
{
    const BYTE* dictPtr = (const BYTE*)dict;
    const BYTE* const dictEnd = dictPtr + dictSize;

    RETURN_ERROR_IF(dictSize <= 8, dictionary_corrupted, "dict is too small");
    assert(MEM_readLE32(dict) == ZSTD_MAGIC_DICTIONARY);   /* dict must be valid */
    dictPtr += 8;   /* skip header = magic + dictID */

    ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, OFTable) == offsetof(ZSTD_entropyDTables_t, LLTable) + sizeof(entropy->LLTable));
    ZSTD_STATIC_ASSERT(offsetof(ZSTD_entropyDTables_t, MLTable) == offsetof(ZSTD_entropyDTables_t, OFTable) + sizeof(entropy->OFTable));
    ZSTD_STATIC_ASSERT(sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable) >= HUF_DECOMPRESS_WORKSPACE_SIZE);
    {   void* const workspace = &entropy->LLTable;   /* use fse tables as temporary workspace; implies fse tables are grouped together */
        size_t const workspaceSize = sizeof(entropy->LLTable) + sizeof(entropy->OFTable) + sizeof(entropy->MLTable);
#ifdef HUF_FORCE_DECOMPRESS_X1
        /* in minimal huffman, we always use X1 variants */
        size_t const hSize = HUF_readDTableX1_wksp(entropy->hufTable,
                                                dictPtr, dictEnd - dictPtr,
                                                workspace, workspaceSize, /* flags */ 0);
#else
        size_t const hSize = HUF_readDTableX2_wksp(entropy->hufTable,
                                                dictPtr, (size_t)(dictEnd - dictPtr),
                                                workspace, workspaceSize, /* flags */ 0);
#endif
        RETURN_ERROR_IF(HUF_isError(hSize), dictionary_corrupted, "");
        dictPtr += hSize;
    }

    {   short offcodeNCount[MaxOff+1];
        unsigned offcodeMaxValue = MaxOff, offcodeLog;
        size_t const offcodeHeaderSize = FSE_readNCount(offcodeNCount, &offcodeMaxValue, &offcodeLog, dictPtr, (size_t)(dictEnd-dictPtr));
        RETURN_ERROR_IF(FSE_isError(offcodeHeaderSize), dictionary_corrupted, "");
        RETURN_ERROR_IF(offcodeMaxValue > MaxOff, dictionary_corrupted, "");
        RETURN_ERROR_IF(offcodeLog > OffFSELog, dictionary_corrupted, "");
        ZSTD_buildFSETable( entropy->OFTable,
                            offcodeNCount, offcodeMaxValue,
                            OF_base, OF_bits,
                            offcodeLog,
                            entropy->workspace, sizeof(entropy->workspace),
                            /* bmi2 */0);
        dictPtr += offcodeHeaderSize;
    }

    {   short matchlengthNCount[MaxML+1];
        unsigned matchlengthMaxValue = MaxML, matchlengthLog;
        size_t const matchlengthHeaderSize = FSE_readNCount(matchlengthNCount, &matchlengthMaxValue, &matchlengthLog, dictPtr, (size_t)(dictEnd-dictPtr));
        RETURN_ERROR_IF(FSE_isError(matchlengthHeaderSize), dictionary_corrupted, "");
        RETURN_ERROR_IF(matchlengthMaxValue > MaxML, dictionary_corrupted, "");
        RETURN_ERROR_IF(matchlengthLog > MLFSELog, dictionary_corrupted, "");
        ZSTD_buildFSETable( entropy->MLTable,
                            matchlengthNCount, matchlengthMaxValue,
                            ML_base, ML_bits,
                            matchlengthLog,
                            entropy->workspace, sizeof(entropy->workspace),
                            /* bmi2 */ 0);
        dictPtr += matchlengthHeaderSize;
    }

    {   short litlengthNCount[MaxLL+1];
        unsigned litlengthMaxValue = MaxLL, litlengthLog;
        size_t const litlengthHeaderSize = FSE_readNCount(litlengthNCount, &litlengthMaxValue, &litlengthLog, dictPtr, (size_t)(dictEnd-dictPtr));
        RETURN_ERROR_IF(FSE_isError(litlengthHeaderSize), dictionary_corrupted, "");
        RETURN_ERROR_IF(litlengthMaxValue > MaxLL, dictionary_corrupted, "");
        RETURN_ERROR_IF(litlengthLog > LLFSELog, dictionary_corrupted, "");
        ZSTD_buildFSETable( entropy->LLTable,
                            litlengthNCount, litlengthMaxValue,
                            LL_base, LL_bits,
                            litlengthLog,
                            entropy->workspace, sizeof(entropy->workspace),
                            /* bmi2 */ 0);
        dictPtr += litlengthHeaderSize;
    }

    RETURN_ERROR_IF(dictPtr+12 > dictEnd, dictionary_corrupted, "");
    {   int i;
        size_t const dictContentSize = (size_t)(dictEnd - (dictPtr+12));
        for (i=0; i<3; i++) {
            U32 const rep = MEM_readLE32(dictPtr); dictPtr += 4;
            RETURN_ERROR_IF(rep==0 || rep > dictContentSize,
                            dictionary_corrupted, "");
            entropy->rep[i] = rep;
    }   }

    return (size_t)(dictPtr - (const BYTE*)dict);
}

static size_t ZSTD_decompress_insertDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
{
    if (dictSize < 8) return ZSTD_refDictContent(dctx, dict, dictSize);
    {   U32 const magic = MEM_readLE32(dict);
        if (magic != ZSTD_MAGIC_DICTIONARY) {
            return ZSTD_refDictContent(dctx, dict, dictSize);   /* pure content mode */
    }   }
    dctx->dictID = MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);

    /* load entropy tables */
    {   size_t const eSize = ZSTD_loadDEntropy(&dctx->entropy, dict, dictSize);
        RETURN_ERROR_IF(ZSTD_isError(eSize), dictionary_corrupted, "");
        dict = (const char*)dict + eSize;
        dictSize -= eSize;
    }
    dctx->litEntropy = dctx->fseEntropy = 1;

    /* reference dictionary content */
    return ZSTD_refDictContent(dctx, dict, dictSize);
}

size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx)
{
    assert(dctx != NULL);
#if ZSTD_TRACE
    dctx->traceCtx = (ZSTD_trace_decompress_begin != NULL) ? ZSTD_trace_decompress_begin(dctx) : 0;
#endif
    dctx->expected = ZSTD_startingInputLength(dctx->format);  /* dctx->format must be properly set */
    dctx->stage = ZSTDds_getFrameHeaderSize;
    dctx->processedCSize = 0;
    dctx->decodedSize = 0;
    dctx->previousDstEnd = NULL;
    dctx->prefixStart = NULL;
    dctx->virtualStart = NULL;
    dctx->dictEnd = NULL;
    dctx->entropy.hufTable[0] = (HUF_DTable)((ZSTD_HUFFDTABLE_CAPACITY_LOG)*0x1000001);  /* cover both little and big endian */
    dctx->litEntropy = dctx->fseEntropy = 0;
    dctx->dictID = 0;
    dctx->bType = bt_reserved;
    dctx->isFrameDecompression = 1;
    ZSTD_STATIC_ASSERT(sizeof(dctx->entropy.rep) == sizeof(repStartValue));
    ZSTD_memcpy(dctx->entropy.rep, repStartValue, sizeof(repStartValue));  /* initial repcodes */
    dctx->LLTptr = dctx->entropy.LLTable;
    dctx->MLTptr = dctx->entropy.MLTable;
    dctx->OFTptr = dctx->entropy.OFTable;
    dctx->HUFptr = dctx->entropy.hufTable;
    return 0;
}

size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
{
    FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , "");
    if (dict && dictSize)
        RETURN_ERROR_IF(
            ZSTD_isError(ZSTD_decompress_insertDictionary(dctx, dict, dictSize)),
            dictionary_corrupted, "");
    return 0;
}


/* ======   ZSTD_DDict   ====== */

size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
{
    DEBUGLOG(4, "ZSTD_decompressBegin_usingDDict");
    assert(dctx != NULL);
    if (ddict) {
        const char* const dictStart = (const char*)ZSTD_DDict_dictContent(ddict);
        size_t const dictSize = ZSTD_DDict_dictSize(ddict);
        const void* const dictEnd = dictStart + dictSize;
        dctx->ddictIsCold = (dctx->dictEnd != dictEnd);
        DEBUGLOG(4, "DDict is %s",
                    dctx->ddictIsCold ? "~cold~" : "hot!");
    }
    FORWARD_IF_ERROR( ZSTD_decompressBegin(dctx) , "");
    if (ddict) {   /* NULL ddict is equivalent to no dictionary */
        ZSTD_copyDDictParameters(dctx, ddict);
    }
    return 0;
}

/*! ZSTD_getDictID_fromDict() :
 *  Provides the dictID stored within dictionary.
 *  if @return == 0, the dictionary is not conformant with Zstandard specification.
 *  It can still be loaded, but as a content-only dictionary. */
unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize)
{
    if (dictSize < 8) return 0;
    if (MEM_readLE32(dict) != ZSTD_MAGIC_DICTIONARY) return 0;
    return MEM_readLE32((const char*)dict + ZSTD_FRAMEIDSIZE);
}

/*! ZSTD_getDictID_fromFrame() :
 *  Provides the dictID required to decompress frame stored within `src`.
 *  If @return == 0, the dictID could not be decoded.
 *  This could for one of the following reasons :
 *  - The frame does not require a dictionary (most common case).
 *  - The frame was built with dictID intentionally removed.
 *    Needed dictionary is a hidden piece of information.
 *    Note : this use case also happens when using a non-conformant dictionary.
 *  - `srcSize` is too small, and as a result, frame header could not be decoded.
 *    Note : possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`.
 *  - This is not a Zstandard frame.
 *  When identifying the exact failure cause, it's possible to use
 *  ZSTD_getFrameHeader(), which will provide a more precise error code. */
unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize)
{
    ZSTD_frameHeader zfp = { 0, 0, 0, ZSTD_frame, 0, 0, 0, 0, 0 };
    size_t const hError = ZSTD_getFrameHeader(&zfp, src, srcSize);
    if (ZSTD_isError(hError)) return 0;
    return zfp.dictID;
}


/*! ZSTD_decompress_usingDDict() :
*   Decompression using a pre-digested Dictionary
*   Use dictionary without significant overhead. */
size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
                                  void* dst, size_t dstCapacity,
                            const void* src, size_t srcSize,
                            const ZSTD_DDict* ddict)
{
    /* pass content and size in case legacy frames are encountered */
    return ZSTD_decompressMultiFrame(dctx, dst, dstCapacity, src, srcSize,
                                     NULL, 0,
                                     ddict);
}


/*=====================================
*   Streaming decompression
*====================================*/

ZSTD_DStream* ZSTD_createDStream(void)
{
    DEBUGLOG(3, "ZSTD_createDStream");
    return ZSTD_createDCtx_internal(ZSTD_defaultCMem);
}

ZSTD_DStream* ZSTD_initStaticDStream(void *workspace, size_t workspaceSize)
{
    return ZSTD_initStaticDCtx(workspace, workspaceSize);
}

ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem)
{
    return ZSTD_createDCtx_internal(customMem);
}

size_t ZSTD_freeDStream(ZSTD_DStream* zds)
{
    return ZSTD_freeDCtx(zds);
}


/* ***  Initialization  *** */

size_t ZSTD_DStreamInSize(void)  { return ZSTD_BLOCKSIZE_MAX + ZSTD_blockHeaderSize; }
size_t ZSTD_DStreamOutSize(void) { return ZSTD_BLOCKSIZE_MAX; }

size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx,
                                   const void* dict, size_t dictSize,
                                         ZSTD_dictLoadMethod_e dictLoadMethod,
                                         ZSTD_dictContentType_e dictContentType)
{
    RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
    ZSTD_clearDict(dctx);
    if (dict && dictSize != 0) {
        dctx->ddictLocal = ZSTD_createDDict_advanced(dict, dictSize, dictLoadMethod, dictContentType, dctx->customMem);
        RETURN_ERROR_IF(dctx->ddictLocal == NULL, memory_allocation, "NULL pointer!");
        dctx->ddict = dctx->ddictLocal;
        dctx->dictUses = ZSTD_use_indefinitely;
    }
    return 0;
}

size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
{
    return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byRef, ZSTD_dct_auto);
}

size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize)
{
    return ZSTD_DCtx_loadDictionary_advanced(dctx, dict, dictSize, ZSTD_dlm_byCopy, ZSTD_dct_auto);
}

size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType)
{
    FORWARD_IF_ERROR(ZSTD_DCtx_loadDictionary_advanced(dctx, prefix, prefixSize, ZSTD_dlm_byRef, dictContentType), "");
    dctx->dictUses = ZSTD_use_once;
    return 0;
}

size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize)
{
    return ZSTD_DCtx_refPrefix_advanced(dctx, prefix, prefixSize, ZSTD_dct_rawContent);
}


/* ZSTD_initDStream_usingDict() :
 * return : expected size, aka ZSTD_startingInputLength().
 * this function cannot fail */
size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize)
{
    DEBUGLOG(4, "ZSTD_initDStream_usingDict");
    FORWARD_IF_ERROR( ZSTD_DCtx_reset(zds, ZSTD_reset_session_only) , "");
    FORWARD_IF_ERROR( ZSTD_DCtx_loadDictionary(zds, dict, dictSize) , "");
    return ZSTD_startingInputLength(zds->format);
}

/* note : this variant can't fail */
size_t ZSTD_initDStream(ZSTD_DStream* zds)
{
    DEBUGLOG(4, "ZSTD_initDStream");
    FORWARD_IF_ERROR(ZSTD_DCtx_reset(zds, ZSTD_reset_session_only), "");
    FORWARD_IF_ERROR(ZSTD_DCtx_refDDict(zds, NULL), "");
    return ZSTD_startingInputLength(zds->format);
}

/* ZSTD_initDStream_usingDDict() :
 * ddict will just be referenced, and must outlive decompression session
 * this function cannot fail */
size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* dctx, const ZSTD_DDict* ddict)
{
    DEBUGLOG(4, "ZSTD_initDStream_usingDDict");
    FORWARD_IF_ERROR( ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only) , "");
    FORWARD_IF_ERROR( ZSTD_DCtx_refDDict(dctx, ddict) , "");
    return ZSTD_startingInputLength(dctx->format);
}

/* ZSTD_resetDStream() :
 * return : expected size, aka ZSTD_startingInputLength().
 * this function cannot fail */
size_t ZSTD_resetDStream(ZSTD_DStream* dctx)
{
    DEBUGLOG(4, "ZSTD_resetDStream");
    FORWARD_IF_ERROR(ZSTD_DCtx_reset(dctx, ZSTD_reset_session_only), "");
    return ZSTD_startingInputLength(dctx->format);
}


size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict)
{
    RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
    ZSTD_clearDict(dctx);
    if (ddict) {
        dctx->ddict = ddict;
        dctx->dictUses = ZSTD_use_indefinitely;
        if (dctx->refMultipleDDicts == ZSTD_rmd_refMultipleDDicts) {
            if (dctx->ddictSet == NULL) {
                dctx->ddictSet = ZSTD_createDDictHashSet(dctx->customMem);
                if (!dctx->ddictSet) {
                    RETURN_ERROR(memory_allocation, "Failed to allocate memory for hash set!");
                }
            }
            assert(!dctx->staticSize);  /* Impossible: ddictSet cannot have been allocated if static dctx */
            FORWARD_IF_ERROR(ZSTD_DDictHashSet_addDDict(dctx->ddictSet, ddict, dctx->customMem), "");
        }
    }
    return 0;
}

/* ZSTD_DCtx_setMaxWindowSize() :
 * note : no direct equivalence in ZSTD_DCtx_setParameter,
 * since this version sets windowSize, and the other sets windowLog */
size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize)
{
    ZSTD_bounds const bounds = ZSTD_dParam_getBounds(ZSTD_d_windowLogMax);
    size_t const min = (size_t)1 << bounds.lowerBound;
    size_t const max = (size_t)1 << bounds.upperBound;
    RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
    RETURN_ERROR_IF(maxWindowSize < min, parameter_outOfBound, "");
    RETURN_ERROR_IF(maxWindowSize > max, parameter_outOfBound, "");
    dctx->maxWindowSize = maxWindowSize;
    return 0;
}

size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format)
{
    return ZSTD_DCtx_setParameter(dctx, ZSTD_d_format, (int)format);
}

ZSTD_bounds ZSTD_dParam_getBounds(ZSTD_dParameter dParam)
{
    ZSTD_bounds bounds = { 0, 0, 0 };
    switch(dParam) {
        case ZSTD_d_windowLogMax:
            bounds.lowerBound = ZSTD_WINDOWLOG_ABSOLUTEMIN;
            bounds.upperBound = ZSTD_WINDOWLOG_MAX;
            return bounds;
        case ZSTD_d_format:
            bounds.lowerBound = (int)ZSTD_f_zstd1;
            bounds.upperBound = (int)ZSTD_f_zstd1_magicless;
            ZSTD_STATIC_ASSERT(ZSTD_f_zstd1 < ZSTD_f_zstd1_magicless);
            return bounds;
        case ZSTD_d_stableOutBuffer:
            bounds.lowerBound = (int)ZSTD_bm_buffered;
            bounds.upperBound = (int)ZSTD_bm_stable;
            return bounds;
        case ZSTD_d_forceIgnoreChecksum:
            bounds.lowerBound = (int)ZSTD_d_validateChecksum;
            bounds.upperBound = (int)ZSTD_d_ignoreChecksum;
            return bounds;
        case ZSTD_d_refMultipleDDicts:
            bounds.lowerBound = (int)ZSTD_rmd_refSingleDDict;
            bounds.upperBound = (int)ZSTD_rmd_refMultipleDDicts;
            return bounds;
        case ZSTD_d_disableHuffmanAssembly:
            bounds.lowerBound = 0;
            bounds.upperBound = 1;
            return bounds;
        case ZSTD_d_maxBlockSize:
            bounds.lowerBound = ZSTD_BLOCKSIZE_MAX_MIN;
            bounds.upperBound = ZSTD_BLOCKSIZE_MAX;
            return bounds;

        default:;
    }
    bounds.error = ERROR(parameter_unsupported);
    return bounds;
}

/* ZSTD_dParam_withinBounds:
 * @return 1 if value is within dParam bounds,
 * 0 otherwise */
static int ZSTD_dParam_withinBounds(ZSTD_dParameter dParam, int value)
{
    ZSTD_bounds const bounds = ZSTD_dParam_getBounds(dParam);
    if (ZSTD_isError(bounds.error)) return 0;
    if (value < bounds.lowerBound) return 0;
    if (value > bounds.upperBound) return 0;
    return 1;
}

#define CHECK_DBOUNDS(p,v) {                \
    RETURN_ERROR_IF(!ZSTD_dParam_withinBounds(p, v), parameter_outOfBound, ""); \
}

size_t ZSTD_DCtx_getParameter(ZSTD_DCtx* dctx, ZSTD_dParameter param, int* value)
{
    switch (param) {
        case ZSTD_d_windowLogMax:
            *value = (int)ZSTD_highbit32((U32)dctx->maxWindowSize);
            return 0;
        case ZSTD_d_format:
            *value = (int)dctx->format;
            return 0;
        case ZSTD_d_stableOutBuffer:
            *value = (int)dctx->outBufferMode;
            return 0;
        case ZSTD_d_forceIgnoreChecksum:
            *value = (int)dctx->forceIgnoreChecksum;
            return 0;
        case ZSTD_d_refMultipleDDicts:
            *value = (int)dctx->refMultipleDDicts;
            return 0;
        case ZSTD_d_disableHuffmanAssembly:
            *value = (int)dctx->disableHufAsm;
            return 0;
        case ZSTD_d_maxBlockSize:
            *value = dctx->maxBlockSizeParam;
            return 0;
        default:;
    }
    RETURN_ERROR(parameter_unsupported, "");
}

size_t ZSTD_DCtx_setParameter(ZSTD_DCtx* dctx, ZSTD_dParameter dParam, int value)
{
    RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
    switch(dParam) {
        case ZSTD_d_windowLogMax:
            if (value == 0) value = ZSTD_WINDOWLOG_LIMIT_DEFAULT;
            CHECK_DBOUNDS(ZSTD_d_windowLogMax, value);
            dctx->maxWindowSize = ((size_t)1) << value;
            return 0;
        case ZSTD_d_format:
            CHECK_DBOUNDS(ZSTD_d_format, value);
            dctx->format = (ZSTD_format_e)value;
            return 0;
        case ZSTD_d_stableOutBuffer:
            CHECK_DBOUNDS(ZSTD_d_stableOutBuffer, value);
            dctx->outBufferMode = (ZSTD_bufferMode_e)value;
            return 0;
        case ZSTD_d_forceIgnoreChecksum:
            CHECK_DBOUNDS(ZSTD_d_forceIgnoreChecksum, value);
            dctx->forceIgnoreChecksum = (ZSTD_forceIgnoreChecksum_e)value;
            return 0;
        case ZSTD_d_refMultipleDDicts:
            CHECK_DBOUNDS(ZSTD_d_refMultipleDDicts, value);
            if (dctx->staticSize != 0) {
                RETURN_ERROR(parameter_unsupported, "Static dctx does not support multiple DDicts!");
            }
            dctx->refMultipleDDicts = (ZSTD_refMultipleDDicts_e)value;
            return 0;
        case ZSTD_d_disableHuffmanAssembly:
            CHECK_DBOUNDS(ZSTD_d_disableHuffmanAssembly, value);
            dctx->disableHufAsm = value != 0;
            return 0;
        case ZSTD_d_maxBlockSize:
            if (value != 0) CHECK_DBOUNDS(ZSTD_d_maxBlockSize, value);
            dctx->maxBlockSizeParam = value;
            return 0;
        default:;
    }
    RETURN_ERROR(parameter_unsupported, "");
}

size_t ZSTD_DCtx_reset(ZSTD_DCtx* dctx, ZSTD_ResetDirective reset)
{
    if ( (reset == ZSTD_reset_session_only)
      || (reset == ZSTD_reset_session_and_parameters) ) {
        dctx->streamStage = zdss_init;
        dctx->noForwardProgress = 0;
        dctx->isFrameDecompression = 1;
    }
    if ( (reset == ZSTD_reset_parameters)
      || (reset == ZSTD_reset_session_and_parameters) ) {
        RETURN_ERROR_IF(dctx->streamStage != zdss_init, stage_wrong, "");
        ZSTD_clearDict(dctx);
        ZSTD_DCtx_resetParameters(dctx);
    }
    return 0;
}


size_t ZSTD_sizeof_DStream(const ZSTD_DStream* dctx)
{
    return ZSTD_sizeof_DCtx(dctx);
}

static size_t ZSTD_decodingBufferSize_internal(unsigned long long windowSize, unsigned long long frameContentSize, size_t blockSizeMax)
{
    size_t const blockSize = MIN((size_t)MIN(windowSize, ZSTD_BLOCKSIZE_MAX), blockSizeMax);
    /* We need blockSize + WILDCOPY_OVERLENGTH worth of buffer so that if a block
     * ends at windowSize + WILDCOPY_OVERLENGTH + 1 bytes, we can start writing
     * the block at the beginning of the output buffer, and maintain a full window.
     *
     * We need another blockSize worth of buffer so that we can store split
     * literals at the end of the block without overwriting the extDict window.
     */
    unsigned long long const neededRBSize = windowSize + (blockSize * 2) + (WILDCOPY_OVERLENGTH * 2);
    unsigned long long const neededSize = MIN(frameContentSize, neededRBSize);
    size_t const minRBSize = (size_t) neededSize;
    RETURN_ERROR_IF((unsigned long long)minRBSize != neededSize,
                    frameParameter_windowTooLarge, "");
    return minRBSize;
}

size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize)
{
    return ZSTD_decodingBufferSize_internal(windowSize, frameContentSize, ZSTD_BLOCKSIZE_MAX);
}

size_t ZSTD_estimateDStreamSize(size_t windowSize)
{
    size_t const blockSize = MIN(windowSize, ZSTD_BLOCKSIZE_MAX);
    size_t const inBuffSize = blockSize;  /* no block can be larger */
    size_t const outBuffSize = ZSTD_decodingBufferSize_min(windowSize, ZSTD_CONTENTSIZE_UNKNOWN);
    return ZSTD_estimateDCtxSize() + inBuffSize + outBuffSize;
}

size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize)
{
    U32 const windowSizeMax = 1U << ZSTD_WINDOWLOG_MAX;   /* note : should be user-selectable, but requires an additional parameter (or a dctx) */
    ZSTD_frameHeader zfh;
    size_t const err = ZSTD_getFrameHeader(&zfh, src, srcSize);
    if (ZSTD_isError(err)) return err;
    RETURN_ERROR_IF(err>0, srcSize_wrong, "");
    RETURN_ERROR_IF(zfh.windowSize > windowSizeMax,
                    frameParameter_windowTooLarge, "");
    return ZSTD_estimateDStreamSize((size_t)zfh.windowSize);
}


/* *****   Decompression   ***** */

static int ZSTD_DCtx_isOverflow(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize)
{
    return (zds->inBuffSize + zds->outBuffSize) >= (neededInBuffSize + neededOutBuffSize) * ZSTD_WORKSPACETOOLARGE_FACTOR;
}

static void ZSTD_DCtx_updateOversizedDuration(ZSTD_DStream* zds, size_t const neededInBuffSize, size_t const neededOutBuffSize)
{
    if (ZSTD_DCtx_isOverflow(zds, neededInBuffSize, neededOutBuffSize))
        zds->oversizedDuration++;
    else
        zds->oversizedDuration = 0;
}

static int ZSTD_DCtx_isOversizedTooLong(ZSTD_DStream* zds)
{
    return zds->oversizedDuration >= ZSTD_WORKSPACETOOLARGE_MAXDURATION;
}

/* Checks that the output buffer hasn't changed if ZSTD_obm_stable is used. */
static size_t ZSTD_checkOutBuffer(ZSTD_DStream const* zds, ZSTD_outBuffer const* output)
{
    ZSTD_outBuffer const expect = zds->expectedOutBuffer;
    /* No requirement when ZSTD_obm_stable is not enabled. */
    if (zds->outBufferMode != ZSTD_bm_stable)
        return 0;
    /* Any buffer is allowed in zdss_init, this must be the same for every other call until
     * the context is reset.
     */
    if (zds->streamStage == zdss_init)
        return 0;
    /* The buffer must match our expectation exactly. */
    if (expect.dst == output->dst && expect.pos == output->pos && expect.size == output->size)
        return 0;
    RETURN_ERROR(dstBuffer_wrong, "ZSTD_d_stableOutBuffer enabled but output differs!");
}

/* Calls ZSTD_decompressContinue() with the right parameters for ZSTD_decompressStream()
 * and updates the stage and the output buffer state. This call is extracted so it can be
 * used both when reading directly from the ZSTD_inBuffer, and in buffered input mode.
 * NOTE: You must break after calling this function since the streamStage is modified.
 */
static size_t ZSTD_decompressContinueStream(
            ZSTD_DStream* zds, char** op, char* oend,
            void const* src, size_t srcSize) {
    int const isSkipFrame = ZSTD_isSkipFrame(zds);
    if (zds->outBufferMode == ZSTD_bm_buffered) {
        size_t const dstSize = isSkipFrame ? 0 : zds->outBuffSize - zds->outStart;
        size_t const decodedSize = ZSTD_decompressContinue(zds,
                zds->outBuff + zds->outStart, dstSize, src, srcSize);
        FORWARD_IF_ERROR(decodedSize, "");
        if (!decodedSize && !isSkipFrame) {
            zds->streamStage = zdss_read;
        } else {
            zds->outEnd = zds->outStart + decodedSize;
            zds->streamStage = zdss_flush;
        }
    } else {
        /* Write directly into the output buffer */
        size_t const dstSize = isSkipFrame ? 0 : (size_t)(oend - *op);
        size_t const decodedSize = ZSTD_decompressContinue(zds, *op, dstSize, src, srcSize);
        FORWARD_IF_ERROR(decodedSize, "");
        *op += decodedSize;
        /* Flushing is not needed. */
        zds->streamStage = zdss_read;
        assert(*op <= oend);
        assert(zds->outBufferMode == ZSTD_bm_stable);
    }
    return 0;
}

size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
{
    const char* const src = (const char*)input->src;
    const char* const istart = input->pos != 0 ? src + input->pos : src;
    const char* const iend = input->size != 0 ? src + input->size : src;
    const char* ip = istart;
    char* const dst = (char*)output->dst;
    char* const ostart = output->pos != 0 ? dst + output->pos : dst;
    char* const oend = output->size != 0 ? dst + output->size : dst;
    char* op = ostart;
    U32 someMoreWork = 1;

    DEBUGLOG(5, "ZSTD_decompressStream");
    RETURN_ERROR_IF(
        input->pos > input->size,
        srcSize_wrong,
        "forbidden. in: pos: %u   vs size: %u",
        (U32)input->pos, (U32)input->size);
    RETURN_ERROR_IF(
        output->pos > output->size,
        dstSize_tooSmall,
        "forbidden. out: pos: %u   vs size: %u",
        (U32)output->pos, (U32)output->size);
    DEBUGLOG(5, "input size : %u", (U32)(input->size - input->pos));
    FORWARD_IF_ERROR(ZSTD_checkOutBuffer(zds, output), "");

    while (someMoreWork) {
        switch(zds->streamStage)
        {
        case zdss_init :
            DEBUGLOG(5, "stage zdss_init => transparent reset ");
            zds->streamStage = zdss_loadHeader;
            zds->lhSize = zds->inPos = zds->outStart = zds->outEnd = 0;
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
            zds->legacyVersion = 0;
#endif
            zds->hostageByte = 0;
            zds->expectedOutBuffer = *output;
            ZSTD_FALLTHROUGH;

        case zdss_loadHeader :
            DEBUGLOG(5, "stage zdss_loadHeader (srcSize : %u)", (U32)(iend - ip));
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
            if (zds->legacyVersion) {
                RETURN_ERROR_IF(zds->staticSize, memory_allocation,
                    "legacy support is incompatible with static dctx");
                {   size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, zds->legacyVersion, output, input);
                    if (hint==0) zds->streamStage = zdss_init;
                    return hint;
            }   }
#endif
            {   size_t const hSize = ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format);
                if (zds->refMultipleDDicts && zds->ddictSet) {
                    ZSTD_DCtx_selectFrameDDict(zds);
                }
                if (ZSTD_isError(hSize)) {
#if defined(ZSTD_LEGACY_SUPPORT) && (ZSTD_LEGACY_SUPPORT>=1)
                    U32 const legacyVersion = ZSTD_isLegacy(istart, iend-istart);
                    if (legacyVersion) {
                        ZSTD_DDict const* const ddict = ZSTD_getDDict(zds);
                        const void* const dict = ddict ? ZSTD_DDict_dictContent(ddict) : NULL;
                        size_t const dictSize = ddict ? ZSTD_DDict_dictSize(ddict) : 0;
                        DEBUGLOG(5, "ZSTD_decompressStream: detected legacy version v0.%u", legacyVersion);
                        RETURN_ERROR_IF(zds->staticSize, memory_allocation,
                            "legacy support is incompatible with static dctx");
                        FORWARD_IF_ERROR(ZSTD_initLegacyStream(&zds->legacyContext,
                                    zds->previousLegacyVersion, legacyVersion,
                                    dict, dictSize), "");
                        zds->legacyVersion = zds->previousLegacyVersion = legacyVersion;
                        {   size_t const hint = ZSTD_decompressLegacyStream(zds->legacyContext, legacyVersion, output, input);
                            if (hint==0) zds->streamStage = zdss_init;   /* or stay in stage zdss_loadHeader */
                            return hint;
                    }   }
#endif
                    return hSize;   /* error */
                }
                if (hSize != 0) {   /* need more input */
                    size_t const toLoad = hSize - zds->lhSize;   /* if hSize!=0, hSize > zds->lhSize */
                    size_t const remainingInput = (size_t)(iend-ip);
                    assert(iend >= ip);
                    if (toLoad > remainingInput) {   /* not enough input to load full header */
                        if (remainingInput > 0) {
                            ZSTD_memcpy(zds->headerBuffer + zds->lhSize, ip, remainingInput);
                            zds->lhSize += remainingInput;
                        }
                        input->pos = input->size;
                        /* check first few bytes */
                        FORWARD_IF_ERROR(
                            ZSTD_getFrameHeader_advanced(&zds->fParams, zds->headerBuffer, zds->lhSize, zds->format),
                            "First few bytes detected incorrect" );
                        /* return hint input size */
                        return (MAX((size_t)ZSTD_FRAMEHEADERSIZE_MIN(zds->format), hSize) - zds->lhSize) + ZSTD_blockHeaderSize;   /* remaining header bytes + next block header */
                    }
                    assert(ip != NULL);
                    ZSTD_memcpy(zds->headerBuffer + zds->lhSize, ip, toLoad); zds->lhSize = hSize; ip += toLoad;
                    break;
            }   }

            /* check for single-pass mode opportunity */
            if (zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
                && zds->fParams.frameType != ZSTD_skippableFrame
                && (U64)(size_t)(oend-op) >= zds->fParams.frameContentSize) {
                size_t const cSize = ZSTD_findFrameCompressedSize_advanced(istart, (size_t)(iend-istart), zds->format);
                if (cSize <= (size_t)(iend-istart)) {
                    /* shortcut : using single-pass mode */
                    size_t const decompressedSize = ZSTD_decompress_usingDDict(zds, op, (size_t)(oend-op), istart, cSize, ZSTD_getDDict(zds));
                    if (ZSTD_isError(decompressedSize)) return decompressedSize;
                    DEBUGLOG(4, "shortcut to single-pass ZSTD_decompress_usingDDict()");
                    assert(istart != NULL);
                    ip = istart + cSize;
                    op = op ? op + decompressedSize : op; /* can occur if frameContentSize = 0 (empty frame) */
                    zds->expected = 0;
                    zds->streamStage = zdss_init;
                    someMoreWork = 0;
                    break;
            }   }

            /* Check output buffer is large enough for ZSTD_odm_stable. */
            if (zds->outBufferMode == ZSTD_bm_stable
                && zds->fParams.frameType != ZSTD_skippableFrame
                && zds->fParams.frameContentSize != ZSTD_CONTENTSIZE_UNKNOWN
                && (U64)(size_t)(oend-op) < zds->fParams.frameContentSize) {
                RETURN_ERROR(dstSize_tooSmall, "ZSTD_obm_stable passed but ZSTD_outBuffer is too small");
            }

            /* Consume header (see ZSTDds_decodeFrameHeader) */
            DEBUGLOG(4, "Consume header");
            FORWARD_IF_ERROR(ZSTD_decompressBegin_usingDDict(zds, ZSTD_getDDict(zds)), "");

            if (zds->format == ZSTD_f_zstd1
                && (MEM_readLE32(zds->headerBuffer) & ZSTD_MAGIC_SKIPPABLE_MASK) == ZSTD_MAGIC_SKIPPABLE_START) {  /* skippable frame */
                zds->expected = MEM_readLE32(zds->headerBuffer + ZSTD_FRAMEIDSIZE);
                zds->stage = ZSTDds_skipFrame;
            } else {
                FORWARD_IF_ERROR(ZSTD_decodeFrameHeader(zds, zds->headerBuffer, zds->lhSize), "");
                zds->expected = ZSTD_blockHeaderSize;
                zds->stage = ZSTDds_decodeBlockHeader;
            }

            /* control buffer memory usage */
            DEBUGLOG(4, "Control max memory usage (%u KB <= max %u KB)",
                        (U32)(zds->fParams.windowSize >>10),
                        (U32)(zds->maxWindowSize >> 10) );
            zds->fParams.windowSize = MAX(zds->fParams.windowSize, 1U << ZSTD_WINDOWLOG_ABSOLUTEMIN);
            RETURN_ERROR_IF(zds->fParams.windowSize > zds->maxWindowSize,
                            frameParameter_windowTooLarge, "");
            if (zds->maxBlockSizeParam != 0)
                zds->fParams.blockSizeMax = MIN(zds->fParams.blockSizeMax, (unsigned)zds->maxBlockSizeParam);

            /* Adapt buffer sizes to frame header instructions */
            {   size_t const neededInBuffSize = MAX(zds->fParams.blockSizeMax, 4 /* frame checksum */);
                size_t const neededOutBuffSize = zds->outBufferMode == ZSTD_bm_buffered
                        ? ZSTD_decodingBufferSize_internal(zds->fParams.windowSize, zds->fParams.frameContentSize, zds->fParams.blockSizeMax)
                        : 0;

                ZSTD_DCtx_updateOversizedDuration(zds, neededInBuffSize, neededOutBuffSize);

                {   int const tooSmall = (zds->inBuffSize < neededInBuffSize) || (zds->outBuffSize < neededOutBuffSize);
                    int const tooLarge = ZSTD_DCtx_isOversizedTooLong(zds);

                    if (tooSmall || tooLarge) {
                        size_t const bufferSize = neededInBuffSize + neededOutBuffSize;
                        DEBUGLOG(4, "inBuff  : from %u to %u",
                                    (U32)zds->inBuffSize, (U32)neededInBuffSize);
                        DEBUGLOG(4, "outBuff : from %u to %u",
                                    (U32)zds->outBuffSize, (U32)neededOutBuffSize);
                        if (zds->staticSize) {  /* static DCtx */
                            DEBUGLOG(4, "staticSize : %u", (U32)zds->staticSize);
                            assert(zds->staticSize >= sizeof(ZSTD_DCtx));  /* controlled at init */
                            RETURN_ERROR_IF(
                                bufferSize > zds->staticSize - sizeof(ZSTD_DCtx),
                                memory_allocation, "");
                        } else {
                            VG_(free)(zds->inBuff);
                            zds->inBuffSize = 0;
                            zds->outBuffSize = 0;
                            zds->inBuff = (char*)VG_(malloc)("zstddeclib.ZSTD_decompressStream.1", bufferSize);
                            RETURN_ERROR_IF(zds->inBuff == NULL, memory_allocation, "");
                        }
                        zds->inBuffSize = neededInBuffSize;
                        zds->outBuff = zds->inBuff + zds->inBuffSize;
                        zds->outBuffSize = neededOutBuffSize;
            }   }   }
            zds->streamStage = zdss_read;
            ZSTD_FALLTHROUGH;

        case zdss_read:
            DEBUGLOG(5, "stage zdss_read");
            {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompressWithInputSize(zds, (size_t)(iend - ip));
                DEBUGLOG(5, "neededInSize = %u", (U32)neededInSize);
                if (neededInSize==0) {  /* end of frame */
                    zds->streamStage = zdss_init;
                    someMoreWork = 0;
                    break;
                }
                if ((size_t)(iend-ip) >= neededInSize) {  /* decode directly from src */
                    FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, ip, neededInSize), "");
                    assert(ip != NULL);
                    ip += neededInSize;
                    /* Function modifies the stage so we must break */
                    break;
            }   }
            if (ip==iend) { someMoreWork = 0; break; }   /* no more input */
            zds->streamStage = zdss_load;
            ZSTD_FALLTHROUGH;

        case zdss_load:
            {   size_t const neededInSize = ZSTD_nextSrcSizeToDecompress(zds);
                size_t const toLoad = neededInSize - zds->inPos;
                int const isSkipFrame = ZSTD_isSkipFrame(zds);
                size_t loadedSize;
                /* At this point we shouldn't be decompressing a block that we can stream. */
                assert(neededInSize == ZSTD_nextSrcSizeToDecompressWithInputSize(zds, (size_t)(iend - ip)));
                if (isSkipFrame) {
                    loadedSize = MIN(toLoad, (size_t)(iend-ip));
                } else {
                    RETURN_ERROR_IF(toLoad > zds->inBuffSize - zds->inPos,
                                    corruption_detected,
                                    "should never happen");
                    loadedSize = ZSTD_limitCopy(zds->inBuff + zds->inPos, toLoad, ip, (size_t)(iend-ip));
                }
                if (loadedSize != 0) {
                    /* ip may be NULL */
                    ip += loadedSize;
                    zds->inPos += loadedSize;
                }
                if (loadedSize < toLoad) { someMoreWork = 0; break; }   /* not enough input, wait for more */

                /* decode loaded input */
                zds->inPos = 0;   /* input is consumed */
                FORWARD_IF_ERROR(ZSTD_decompressContinueStream(zds, &op, oend, zds->inBuff, neededInSize), "");
                /* Function modifies the stage so we must break */
                break;
            }
        case zdss_flush:
            {
                size_t const toFlushSize = zds->outEnd - zds->outStart;
                size_t const flushedSize = ZSTD_limitCopy(op, (size_t)(oend-op), zds->outBuff + zds->outStart, toFlushSize);

                op = op ? op + flushedSize : op;

                zds->outStart += flushedSize;
                if (flushedSize == toFlushSize) {  /* flush completed */
                    zds->streamStage = zdss_read;
                    if ( (zds->outBuffSize < zds->fParams.frameContentSize)
                        && (zds->outStart + zds->fParams.blockSizeMax > zds->outBuffSize) ) {
                        DEBUGLOG(5, "restart filling outBuff from beginning (left:%i, needed:%u)",
                                (int)(zds->outBuffSize - zds->outStart),
                                (U32)zds->fParams.blockSizeMax);
                        zds->outStart = zds->outEnd = 0;
                    }
                    break;
            }   }
            /* cannot complete flush */
            someMoreWork = 0;
            break;

        default:
            assert(0);    /* impossible */
            RETURN_ERROR(GENERIC, "impossible to reach");   /* some compilers require default to do something */
    }   }

    /* result */
    input->pos = (size_t)(ip - (const char*)(input->src));
    output->pos = (size_t)(op - (char*)(output->dst));

    /* Update the expected output buffer for ZSTD_obm_stable. */
    zds->expectedOutBuffer = *output;

    if ((ip==istart) && (op==ostart)) {  /* no forward progress */
        zds->noForwardProgress ++;
        if (zds->noForwardProgress >= ZSTD_NO_FORWARD_PROGRESS_MAX) {
            RETURN_ERROR_IF(op==oend, noForwardProgress_destFull, "");
            RETURN_ERROR_IF(ip==iend, noForwardProgress_inputEmpty, "");
            assert(0);
        }
    } else {
        zds->noForwardProgress = 0;
    }
    {   size_t nextSrcSizeHint = ZSTD_nextSrcSizeToDecompress(zds);
        if (!nextSrcSizeHint) {   /* frame fully decoded */
            if (zds->outEnd == zds->outStart) {  /* output fully flushed */
                if (zds->hostageByte) {
                    if (input->pos >= input->size) {
                        /* can't release hostage (not present) */
                        zds->streamStage = zdss_read;
                        return 1;
                    }
                    input->pos++;  /* release hostage */
                }   /* zds->hostageByte */
                return 0;
            }  /* zds->outEnd == zds->outStart */
            if (!zds->hostageByte) { /* output not fully flushed; keep last byte as hostage; will be released when all output is flushed */
                input->pos--;   /* note : pos > 0, otherwise, impossible to finish reading last block */
                zds->hostageByte=1;
            }
            return 1;
        }  /* nextSrcSizeHint==0 */
        nextSrcSizeHint += ZSTD_blockHeaderSize * (ZSTD_nextInputType(zds) == ZSTDnit_block);   /* preload header of next block */
        assert(zds->inPos <= nextSrcSizeHint);
        nextSrcSizeHint -= zds->inPos;   /* part already loaded*/
        return nextSrcSizeHint;
    }
}

size_t ZSTD_decompressStream_simpleArgs (
                            ZSTD_DCtx* dctx,
                            void* dst, size_t dstCapacity, size_t* dstPos,
                      const void* src, size_t srcSize, size_t* srcPos)
{
    ZSTD_outBuffer output;
    ZSTD_inBuffer  input;
    output.dst = dst;
    output.size = dstCapacity;
    output.pos = *dstPos;
    input.src = src;
    input.size = srcSize;
    input.pos = *srcPos;
    {   size_t const cErr = ZSTD_decompressStream(dctx, &output, &input);
        *dstPos = output.pos;
        *srcPos = input.pos;
        return cErr;
    }
}
/**** ended inlining decompress/zstd_decompress.c ****/
/**** start inlining decompress/zstd_decompress_block.c ****/
/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */

/* zstd_decompress_block :
 * this module takes care of decompressing _compressed_ block */

/*-*******************************************************
*  Dependencies
*********************************************************/
/**** skipping file: ../common/zstd_deps.h ****/
/**** skipping file: ../common/compiler.h ****/
/**** skipping file: ../common/cpu.h ****/
/**** skipping file: ../common/mem.h ****/
#define FSE_STATIC_LINKING_ONLY
/**** skipping file: ../common/fse.h ****/
/**** skipping file: ../common/huf.h ****/
/**** skipping file: ../common/zstd_internal.h ****/
/**** skipping file: zstd_decompress_internal.h ****/
/**** skipping file: zstd_ddict.h ****/
/**** skipping file: zstd_decompress_block.h ****/
/**** skipping file: ../common/bits.h ****/

/*_*******************************************************
*  Macros
**********************************************************/

/* These two optional macros force the use one way or another of the two
 * ZSTD_decompressSequences implementations. You can't force in both directions
 * at the same time.
 */
#if defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
    defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
#error "Cannot force the use of the short and the long ZSTD_decompressSequences variants!"
#endif


/*_*******************************************************
*  Memory operations
**********************************************************/
static void ZSTD_copy4(void* dst, const void* src) { ZSTD_memcpy(dst, src, 4); }


/*-*************************************************************
 *   Block decoding
 ***************************************************************/

static size_t ZSTD_blockSizeMax(ZSTD_DCtx const* dctx)
{
    size_t const blockSizeMax = dctx->isFrameDecompression ? dctx->fParams.blockSizeMax : ZSTD_BLOCKSIZE_MAX;
    assert(blockSizeMax <= ZSTD_BLOCKSIZE_MAX);
    return blockSizeMax;
}

/*! ZSTD_getcBlockSize() :
 *  Provides the size of compressed block from block header `src` */
size_t ZSTD_getcBlockSize(const void* src, size_t srcSize,
                          blockProperties_t* bpPtr)
{
    RETURN_ERROR_IF(srcSize < ZSTD_blockHeaderSize, srcSize_wrong, "");

    {   U32 const cBlockHeader = MEM_readLE24(src);
        U32 const cSize = cBlockHeader >> 3;
        bpPtr->lastBlock = cBlockHeader & 1;
        bpPtr->blockType = (blockType_e)((cBlockHeader >> 1) & 3);
        bpPtr->origSize = cSize;   /* only useful for RLE */
        if (bpPtr->blockType == bt_rle) return 1;
        RETURN_ERROR_IF(bpPtr->blockType == bt_reserved, corruption_detected, "");
        return cSize;
    }
}

/* Allocate buffer for literals, either overlapping current dst, or split between dst and litExtraBuffer, or stored entirely within litExtraBuffer */
static void ZSTD_allocateLiteralsBuffer(ZSTD_DCtx* dctx, void* const dst, const size_t dstCapacity, const size_t litSize,
    const streaming_operation streaming, const size_t expectedWriteSize, const unsigned splitImmediately)
{
    size_t const blockSizeMax = ZSTD_blockSizeMax(dctx);
    assert(litSize <= blockSizeMax);
    assert(dctx->isFrameDecompression || streaming == not_streaming);
    assert(expectedWriteSize <= blockSizeMax);
    if (streaming == not_streaming && dstCapacity > blockSizeMax + WILDCOPY_OVERLENGTH + litSize + WILDCOPY_OVERLENGTH) {
        /* If we aren't streaming, we can just put the literals after the output
         * of the current block. We don't need to worry about overwriting the
         * extDict of our window, because it doesn't exist.
         * So if we have space after the end of the block, just put it there.
         */
        dctx->litBuffer = (BYTE*)dst + blockSizeMax + WILDCOPY_OVERLENGTH;
        dctx->litBufferEnd = dctx->litBuffer + litSize;
        dctx->litBufferLocation = ZSTD_in_dst;
    } else if (litSize <= ZSTD_LITBUFFEREXTRASIZE) {
        /* Literals fit entirely within the extra buffer, put them there to avoid
         * having to split the literals.
         */
        dctx->litBuffer = dctx->litExtraBuffer;
        dctx->litBufferEnd = dctx->litBuffer + litSize;
        dctx->litBufferLocation = ZSTD_not_in_dst;
    } else {
        assert(blockSizeMax > ZSTD_LITBUFFEREXTRASIZE);
        /* Literals must be split between the output block and the extra lit
         * buffer. We fill the extra lit buffer with the tail of the literals,
         * and put the rest of the literals at the end of the block, with
         * WILDCOPY_OVERLENGTH of buffer room to allow for overreads.
         * This MUST not write more than our maxBlockSize beyond dst, because in
         * streaming mode, that could overwrite part of our extDict window.
         */
        if (splitImmediately) {
            /* won't fit in litExtraBuffer, so it will be split between end of dst and extra buffer */
            dctx->litBuffer = (BYTE*)dst + expectedWriteSize - litSize + ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH;
            dctx->litBufferEnd = dctx->litBuffer + litSize - ZSTD_LITBUFFEREXTRASIZE;
        } else {
            /* initially this will be stored entirely in dst during huffman decoding, it will partially be shifted to litExtraBuffer after */
            dctx->litBuffer = (BYTE*)dst + expectedWriteSize - litSize;
            dctx->litBufferEnd = (BYTE*)dst + expectedWriteSize;
        }
        dctx->litBufferLocation = ZSTD_split;
        assert(dctx->litBufferEnd <= (BYTE*)dst + expectedWriteSize);
    }
}

/*! ZSTD_decodeLiteralsBlock() :
 * Where it is possible to do so without being stomped by the output during decompression, the literals block will be stored
 * in the dstBuffer.  If there is room to do so, it will be stored in full in the excess dst space after where the current
 * block will be output.  Otherwise it will be stored at the end of the current dst blockspace, with a small portion being
 * stored in dctx->litExtraBuffer to help keep it "ahead" of the current output write.
 *
 * @return : nb of bytes read from src (< srcSize )
 *  note : symbol not declared but exposed for fullbench */
static size_t ZSTD_decodeLiteralsBlock(ZSTD_DCtx* dctx,
                          const void* src, size_t srcSize,   /* note : srcSize < BLOCKSIZE */
                          void* dst, size_t dstCapacity, const streaming_operation streaming)
{
    DEBUGLOG(5, "ZSTD_decodeLiteralsBlock");
    RETURN_ERROR_IF(srcSize < MIN_CBLOCK_SIZE, corruption_detected, "");

    {   const BYTE* const istart = (const BYTE*) src;
        symbolEncodingType_e const litEncType = (symbolEncodingType_e)(istart[0] & 3);
        size_t const blockSizeMax = ZSTD_blockSizeMax(dctx);

        switch(litEncType)
        {
        case set_repeat:
            DEBUGLOG(5, "set_repeat flag : re-using stats from previous compressed literals block");
            RETURN_ERROR_IF(dctx->litEntropy==0, dictionary_corrupted, "");
            ZSTD_FALLTHROUGH;

        case set_compressed:
            RETURN_ERROR_IF(srcSize < 5, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need up to 5 for case 3");
            {   size_t lhSize, litSize, litCSize;
                U32 singleStream=0;
                U32 const lhlCode = (istart[0] >> 2) & 3;
                U32 const lhc = MEM_readLE32(istart);
                size_t hufSuccess;
                size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity);
                int const flags = 0
                    | (ZSTD_DCtx_get_bmi2(dctx) ? HUF_flags_bmi2 : 0)
                    | (dctx->disableHufAsm ? HUF_flags_disableAsm : 0);
                switch(lhlCode)
                {
                case 0: case 1: default:   /* note : default is impossible, since lhlCode into [0..3] */
                    /* 2 - 2 - 10 - 10 */
                    singleStream = !lhlCode;
                    lhSize = 3;
                    litSize  = (lhc >> 4) & 0x3FF;
                    litCSize = (lhc >> 14) & 0x3FF;
                    break;
                case 2:
                    /* 2 - 2 - 14 - 14 */
                    lhSize = 4;
                    litSize  = (lhc >> 4) & 0x3FFF;
                    litCSize = lhc >> 18;
                    break;
                case 3:
                    /* 2 - 2 - 18 - 18 */
                    lhSize = 5;
                    litSize  = (lhc >> 4) & 0x3FFFF;
                    litCSize = (lhc >> 22) + ((size_t)istart[4] << 10);
                    break;
                }
                RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled");
                RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, "");
                if (!singleStream)
                    RETURN_ERROR_IF(litSize < MIN_LITERALS_FOR_4_STREAMS, literals_headerWrong,
                        "Not enough literals (%zu) for the 4-streams mode (min %u)",
                        litSize, MIN_LITERALS_FOR_4_STREAMS);
                RETURN_ERROR_IF(litCSize + lhSize > srcSize, corruption_detected, "");
                RETURN_ERROR_IF(expectedWriteSize < litSize , dstSize_tooSmall, "");
                ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 0);

                /* prefetch huffman table if cold */
                if (dctx->ddictIsCold && (litSize > 768 /* heuristic */)) {
                    PREFETCH_AREA(dctx->HUFptr, sizeof(dctx->entropy.hufTable));
                }

                if (litEncType==set_repeat) {
                    if (singleStream) {
                        hufSuccess = HUF_decompress1X_usingDTable(
                            dctx->litBuffer, litSize, istart+lhSize, litCSize,
                            dctx->HUFptr, flags);
                    } else {
                        assert(litSize >= MIN_LITERALS_FOR_4_STREAMS);
                        hufSuccess = HUF_decompress4X_usingDTable(
                            dctx->litBuffer, litSize, istart+lhSize, litCSize,
                            dctx->HUFptr, flags);
                    }
                } else {
                    if (singleStream) {
#if defined(HUF_FORCE_DECOMPRESS_X2)
                        hufSuccess = HUF_decompress1X_DCtx_wksp(
                            dctx->entropy.hufTable, dctx->litBuffer, litSize,
                            istart+lhSize, litCSize, dctx->workspace,
                            sizeof(dctx->workspace), flags);
#else
                        hufSuccess = HUF_decompress1X1_DCtx_wksp(
                            dctx->entropy.hufTable, dctx->litBuffer, litSize,
                            istart+lhSize, litCSize, dctx->workspace,
                            sizeof(dctx->workspace), flags);
#endif
                    } else {
                        hufSuccess = HUF_decompress4X_hufOnly_wksp(
                            dctx->entropy.hufTable, dctx->litBuffer, litSize,
                            istart+lhSize, litCSize, dctx->workspace,
                            sizeof(dctx->workspace), flags);
                    }
                }
                if (dctx->litBufferLocation == ZSTD_split)
                {
                    assert(litSize > ZSTD_LITBUFFEREXTRASIZE);
                    ZSTD_memcpy(dctx->litExtraBuffer, dctx->litBufferEnd - ZSTD_LITBUFFEREXTRASIZE, ZSTD_LITBUFFEREXTRASIZE);
                    ZSTD_memmove(dctx->litBuffer + ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH, dctx->litBuffer, litSize - ZSTD_LITBUFFEREXTRASIZE);
                    dctx->litBuffer += ZSTD_LITBUFFEREXTRASIZE - WILDCOPY_OVERLENGTH;
                    dctx->litBufferEnd -= WILDCOPY_OVERLENGTH;
                    assert(dctx->litBufferEnd <= (BYTE*)dst + blockSizeMax);
                }

                RETURN_ERROR_IF(HUF_isError(hufSuccess), corruption_detected, "");

                dctx->litPtr = dctx->litBuffer;
                dctx->litSize = litSize;
                dctx->litEntropy = 1;
                if (litEncType==set_compressed) dctx->HUFptr = dctx->entropy.hufTable;
                return litCSize + lhSize;
            }

        case set_basic:
            {   size_t litSize, lhSize;
                U32 const lhlCode = ((istart[0]) >> 2) & 3;
                size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity);
                switch(lhlCode)
                {
                case 0: case 2: default:   /* note : default is impossible, since lhlCode into [0..3] */
                    lhSize = 1;
                    litSize = istart[0] >> 3;
                    break;
                case 1:
                    lhSize = 2;
                    litSize = MEM_readLE16(istart) >> 4;
                    break;
                case 3:
                    lhSize = 3;
                    RETURN_ERROR_IF(srcSize<3, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize = 3");
                    litSize = MEM_readLE24(istart) >> 4;
                    break;
                }

                RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled");
                RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, "");
                RETURN_ERROR_IF(expectedWriteSize < litSize, dstSize_tooSmall, "");
                ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 1);
                if (lhSize+litSize+WILDCOPY_OVERLENGTH > srcSize) {  /* risk reading beyond src buffer with wildcopy */
                    RETURN_ERROR_IF(litSize+lhSize > srcSize, corruption_detected, "");
                    if (dctx->litBufferLocation == ZSTD_split)
                    {
                        ZSTD_memcpy(dctx->litBuffer, istart + lhSize, litSize - ZSTD_LITBUFFEREXTRASIZE);
                        ZSTD_memcpy(dctx->litExtraBuffer, istart + lhSize + litSize - ZSTD_LITBUFFEREXTRASIZE, ZSTD_LITBUFFEREXTRASIZE);
                    }
                    else
                    {
                        ZSTD_memcpy(dctx->litBuffer, istart + lhSize, litSize);
                    }
                    dctx->litPtr = dctx->litBuffer;
                    dctx->litSize = litSize;
                    return lhSize+litSize;
                }
                /* direct reference into compressed stream */
                dctx->litPtr = istart+lhSize;
                dctx->litSize = litSize;
                dctx->litBufferEnd = dctx->litPtr + litSize;
                dctx->litBufferLocation = ZSTD_not_in_dst;
                return lhSize+litSize;
            }

        case set_rle:
            {   U32 const lhlCode = ((istart[0]) >> 2) & 3;
                size_t litSize, lhSize;
                size_t expectedWriteSize = MIN(blockSizeMax, dstCapacity);
                switch(lhlCode)
                {
                case 0: case 2: default:   /* note : default is impossible, since lhlCode into [0..3] */
                    lhSize = 1;
                    litSize = istart[0] >> 3;
                    break;
                case 1:
                    lhSize = 2;
                    RETURN_ERROR_IF(srcSize<3, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize+1 = 3");
                    litSize = MEM_readLE16(istart) >> 4;
                    break;
                case 3:
                    lhSize = 3;
                    RETURN_ERROR_IF(srcSize<4, corruption_detected, "srcSize >= MIN_CBLOCK_SIZE == 2; here we need lhSize+1 = 4");
                    litSize = MEM_readLE24(istart) >> 4;
                    break;
                }
                RETURN_ERROR_IF(litSize > 0 && dst == NULL, dstSize_tooSmall, "NULL not handled");
                RETURN_ERROR_IF(litSize > blockSizeMax, corruption_detected, "");
                RETURN_ERROR_IF(expectedWriteSize < litSize, dstSize_tooSmall, "");
                ZSTD_allocateLiteralsBuffer(dctx, dst, dstCapacity, litSize, streaming, expectedWriteSize, 1);
                if (dctx->litBufferLocation == ZSTD_split)
                {
                    ZSTD_memset(dctx->litBuffer, istart[lhSize], litSize - ZSTD_LITBUFFEREXTRASIZE);
                    ZSTD_memset(dctx->litExtraBuffer, istart[lhSize], ZSTD_LITBUFFEREXTRASIZE);
                }
                else
                {
                    ZSTD_memset(dctx->litBuffer, istart[lhSize], litSize);
                }
                dctx->litPtr = dctx->litBuffer;
                dctx->litSize = litSize;
                return lhSize+1;
            }
        default:
            RETURN_ERROR(corruption_detected, "impossible");
        }
    }
}

/* Hidden declaration for fullbench */
size_t ZSTD_decodeLiteralsBlock_wrapper(ZSTD_DCtx* dctx,
                          const void* src, size_t srcSize,
                          void* dst, size_t dstCapacity);
size_t ZSTD_decodeLiteralsBlock_wrapper(ZSTD_DCtx* dctx,
                          const void* src, size_t srcSize,
                          void* dst, size_t dstCapacity)
{
    dctx->isFrameDecompression = 0;
    return ZSTD_decodeLiteralsBlock(dctx, src, srcSize, dst, dstCapacity, not_streaming);
}

/* Default FSE distribution tables.
 * These are pre-calculated FSE decoding tables using default distributions as defined in specification :
 * https://github.com/facebook/zstd/blob/release/doc/zstd_compression_format.md#default-distributions
 * They were generated programmatically with following method :
 * - start from default distributions, present in /lib/common/zstd_internal.h
 * - generate tables normally, using ZSTD_buildFSETable()
 * - printout the content of tables
 * - pretify output, report below, test with fuzzer to ensure it's correct */

/* Default FSE distribution table for Literal Lengths */
static const ZSTD_seqSymbol LL_defaultDTable[(1<<LL_DEFAULTNORMLOG)+1] = {
     {  1,  1,  1, LL_DEFAULTNORMLOG},  /* header : fastMode, tableLog */
     /* nextState, nbAddBits, nbBits, baseVal */
     {  0,  0,  4,    0},  { 16,  0,  4,    0},
     { 32,  0,  5,    1},  {  0,  0,  5,    3},
     {  0,  0,  5,    4},  {  0,  0,  5,    6},
     {  0,  0,  5,    7},  {  0,  0,  5,    9},
     {  0,  0,  5,   10},  {  0,  0,  5,   12},
     {  0,  0,  6,   14},  {  0,  1,  5,   16},
     {  0,  1,  5,   20},  {  0,  1,  5,   22},
     {  0,  2,  5,   28},  {  0,  3,  5,   32},
     {  0,  4,  5,   48},  { 32,  6,  5,   64},
     {  0,  7,  5,  128},  {  0,  8,  6,  256},
     {  0, 10,  6, 1024},  {  0, 12,  6, 4096},
     { 32,  0,  4,    0},  {  0,  0,  4,    1},
     {  0,  0,  5,    2},  { 32,  0,  5,    4},
     {  0,  0,  5,    5},  { 32,  0,  5,    7},
     {  0,  0,  5,    8},  { 32,  0,  5,   10},
     {  0,  0,  5,   11},  {  0,  0,  6,   13},
     { 32,  1,  5,   16},  {  0,  1,  5,   18},
     { 32,  1,  5,   22},  {  0,  2,  5,   24},
     { 32,  3,  5,   32},  {  0,  3,  5,   40},
     {  0,  6,  4,   64},  { 16,  6,  4,   64},
     { 32,  7,  5,  128},  {  0,  9,  6,  512},
     {  0, 11,  6, 2048},  { 48,  0,  4,    0},
     { 16,  0,  4,    1},  { 32,  0,  5,    2},
     { 32,  0,  5,    3},  { 32,  0,  5,    5},
     { 32,  0,  5,    6},  { 32,  0,  5,    8},
     { 32,  0,  5,    9},  { 32,  0,  5,   11},
     { 32,  0,  5,   12},  {  0,  0,  6,   15},
     { 32,  1,  5,   18},  { 32,  1,  5,   20},
     { 32,  2,  5,   24},  { 32,  2,  5,   28},
     { 32,  3,  5,   40},  { 32,  4,  5,   48},
     {  0, 16,  6,65536},  {  0, 15,  6,32768},
     {  0, 14,  6,16384},  {  0, 13,  6, 8192},
};   /* LL_defaultDTable */

/* Default FSE distribution table for Offset Codes */
static const ZSTD_seqSymbol OF_defaultDTable[(1<<OF_DEFAULTNORMLOG)+1] = {
    {  1,  1,  1, OF_DEFAULTNORMLOG},  /* header : fastMode, tableLog */
    /* nextState, nbAddBits, nbBits, baseVal */
    {  0,  0,  5,    0},     {  0,  6,  4,   61},
    {  0,  9,  5,  509},     {  0, 15,  5,32765},
    {  0, 21,  5,2097149},   {  0,  3,  5,    5},
    {  0,  7,  4,  125},     {  0, 12,  5, 4093},
    {  0, 18,  5,262141},    {  0, 23,  5,8388605},
    {  0,  5,  5,   29},     {  0,  8,  4,  253},
    {  0, 14,  5,16381},     {  0, 20,  5,1048573},
    {  0,  2,  5,    1},     { 16,  7,  4,  125},
    {  0, 11,  5, 2045},     {  0, 17,  5,131069},
    {  0, 22,  5,4194301},   {  0,  4,  5,   13},
    { 16,  8,  4,  253},     {  0, 13,  5, 8189},
    {  0, 19,  5,524285},    {  0,  1,  5,    1},
    { 16,  6,  4,   61},     {  0, 10,  5, 1021},
    {  0, 16,  5,65533},     {  0, 28,  5,268435453},
    {  0, 27,  5,134217725}, {  0, 26,  5,67108861},
    {  0, 25,  5,33554429},  {  0, 24,  5,16777213},
};   /* OF_defaultDTable */


/* Default FSE distribution table for Match Lengths */
static const ZSTD_seqSymbol ML_defaultDTable[(1<<ML_DEFAULTNORMLOG)+1] = {
    {  1,  1,  1, ML_DEFAULTNORMLOG},  /* header : fastMode, tableLog */
    /* nextState, nbAddBits, nbBits, baseVal */
    {  0,  0,  6,    3},  {  0,  0,  4,    4},
    { 32,  0,  5,    5},  {  0,  0,  5,    6},
    {  0,  0,  5,    8},  {  0,  0,  5,    9},
    {  0,  0,  5,   11},  {  0,  0,  6,   13},
    {  0,  0,  6,   16},  {  0,  0,  6,   19},
    {  0,  0,  6,   22},  {  0,  0,  6,   25},
    {  0,  0,  6,   28},  {  0,  0,  6,   31},
    {  0,  0,  6,   34},  {  0,  1,  6,   37},
    {  0,  1,  6,   41},  {  0,  2,  6,   47},
    {  0,  3,  6,   59},  {  0,  4,  6,   83},
    {  0,  7,  6,  131},  {  0,  9,  6,  515},
    { 16,  0,  4,    4},  {  0,  0,  4,    5},
    { 32,  0,  5,    6},  {  0,  0,  5,    7},
    { 32,  0,  5,    9},  {  0,  0,  5,   10},
    {  0,  0,  6,   12},  {  0,  0,  6,   15},
    {  0,  0,  6,   18},  {  0,  0,  6,   21},
    {  0,  0,  6,   24},  {  0,  0,  6,   27},
    {  0,  0,  6,   30},  {  0,  0,  6,   33},
    {  0,  1,  6,   35},  {  0,  1,  6,   39},
    {  0,  2,  6,   43},  {  0,  3,  6,   51},
    {  0,  4,  6,   67},  {  0,  5,  6,   99},
    {  0,  8,  6,  259},  { 32,  0,  4,    4},
    { 48,  0,  4,    4},  { 16,  0,  4,    5},
    { 32,  0,  5,    7},  { 32,  0,  5,    8},
    { 32,  0,  5,   10},  { 32,  0,  5,   11},
    {  0,  0,  6,   14},  {  0,  0,  6,   17},
    {  0,  0,  6,   20},  {  0,  0,  6,   23},
    {  0,  0,  6,   26},  {  0,  0,  6,   29},
    {  0,  0,  6,   32},  {  0, 16,  6,65539},
    {  0, 15,  6,32771},  {  0, 14,  6,16387},
    {  0, 13,  6, 8195},  {  0, 12,  6, 4099},
    {  0, 11,  6, 2051},  {  0, 10,  6, 1027},
};   /* ML_defaultDTable */


static void ZSTD_buildSeqTable_rle(ZSTD_seqSymbol* dt, U32 baseValue, U8 nbAddBits)
{
    void* ptr = dt;
    ZSTD_seqSymbol_header* const DTableH = (ZSTD_seqSymbol_header*)ptr;
    ZSTD_seqSymbol* const cell = dt + 1;

    DTableH->tableLog = 0;
    DTableH->fastMode = 0;

    cell->nbBits = 0;
    cell->nextState = 0;
    assert(nbAddBits < 255);
    cell->nbAdditionalBits = nbAddBits;
    cell->baseValue = baseValue;
}


/* ZSTD_buildFSETable() :
 * generate FSE decoding table for one symbol (ll, ml or off)
 * cannot fail if input is valid =>
 * all inputs are presumed validated at this stage */
FORCE_INLINE_TEMPLATE
void ZSTD_buildFSETable_body(ZSTD_seqSymbol* dt,
            const short* normalizedCounter, unsigned maxSymbolValue,
            const U32* baseValue, const U8* nbAdditionalBits,
            unsigned tableLog, void* wksp, size_t wkspSize)
{
    ZSTD_seqSymbol* const tableDecode = dt+1;
    U32 const maxSV1 = maxSymbolValue + 1;
    U32 const tableSize = 1 << tableLog;

    U16* symbolNext = (U16*)wksp;
    BYTE* spread = (BYTE*)(symbolNext + MaxSeq + 1);
    U32 highThreshold = tableSize - 1;


    /* Sanity Checks */
    assert(maxSymbolValue <= MaxSeq);
    assert(tableLog <= MaxFSELog);
    assert(wkspSize >= ZSTD_BUILD_FSE_TABLE_WKSP_SIZE);
    (void)wkspSize;
    /* Init, lay down lowprob symbols */
    {   ZSTD_seqSymbol_header DTableH;
        DTableH.tableLog = tableLog;
        DTableH.fastMode = 1;
        {   S16 const largeLimit= (S16)(1 << (tableLog-1));
            U32 s;
            for (s=0; s<maxSV1; s++) {
                if (normalizedCounter[s]==-1) {
                    tableDecode[highThreshold--].baseValue = s;
                    symbolNext[s] = 1;
                } else {
                    if (normalizedCounter[s] >= largeLimit) DTableH.fastMode=0;
                    assert(normalizedCounter[s]>=0);
                    symbolNext[s] = (U16)normalizedCounter[s];
        }   }   }
        ZSTD_memcpy(dt, &DTableH, sizeof(DTableH));
    }

    /* Spread symbols */
    assert(tableSize <= 512);
    /* Specialized symbol spreading for the case when there are
     * no low probability (-1 count) symbols. When compressing
     * small blocks we avoid low probability symbols to hit this
     * case, since header decoding speed matters more.
     */
    if (highThreshold == tableSize - 1) {
        size_t const tableMask = tableSize-1;
        size_t const step = FSE_TABLESTEP(tableSize);
        /* First lay down the symbols in order.
         * We use a uint64_t to lay down 8 bytes at a time. This reduces branch
         * misses since small blocks generally have small table logs, so nearly
         * all symbols have counts <= 8. We ensure we have 8 bytes at the end of
         * our buffer to handle the over-write.
         */
        {
            U64 const add = 0x0101010101010101ull;
            size_t pos = 0;
            U64 sv = 0;
            U32 s;
            for (s=0; s<maxSV1; ++s, sv += add) {
                int i;
                int const n = normalizedCounter[s];
                MEM_write64(spread + pos, sv);
                for (i = 8; i < n; i += 8) {
                    MEM_write64(spread + pos + i, sv);
                }
                assert(n>=0);
                pos += (size_t)n;
            }
        }
        /* Now we spread those positions across the table.
         * The benefit of doing it in two stages is that we avoid the
         * variable size inner loop, which caused lots of branch misses.
         * Now we can run through all the positions without any branch misses.
         * We unroll the loop twice, since that is what empirically worked best.
         */
        {
            size_t position = 0;
            size_t s;
            size_t const unroll = 2;
            assert(tableSize % unroll == 0); /* FSE_MIN_TABLELOG is 5 */
            for (s = 0; s < (size_t)tableSize; s += unroll) {
                size_t u;
                for (u = 0; u < unroll; ++u) {
                    size_t const uPosition = (position + (u * step)) & tableMask;
                    tableDecode[uPosition].baseValue = spread[s + u];
                }
                position = (position + (unroll * step)) & tableMask;
            }
            assert(position == 0);
        }
    } else {
        U32 const tableMask = tableSize-1;
        U32 const step = FSE_TABLESTEP(tableSize);
        U32 s, position = 0;
        for (s=0; s<maxSV1; s++) {
            int i;
            int const n = normalizedCounter[s];
            for (i=0; i<n; i++) {
                tableDecode[position].baseValue = s;
                position = (position + step) & tableMask;
                while (UNLIKELY(position > highThreshold)) position = (position + step) & tableMask;   /* lowprob area */
        }   }
        assert(position == 0); /* position must reach all cells once, otherwise normalizedCounter is incorrect */
    }

    /* Build Decoding table */
    {
        U32 u;
        for (u=0; u<tableSize; u++) {
            U32 const symbol = tableDecode[u].baseValue;
            U32 const nextState = symbolNext[symbol]++;
            tableDecode[u].nbBits = (BYTE) (tableLog - ZSTD_highbit32(nextState) );
            tableDecode[u].nextState = (U16) ( (nextState << tableDecode[u].nbBits) - tableSize);
            assert(nbAdditionalBits[symbol] < 255);
            tableDecode[u].nbAdditionalBits = nbAdditionalBits[symbol];
            tableDecode[u].baseValue = baseValue[symbol];
        }
    }
}

/* Avoids the FORCE_INLINE of the _body() function. */
static void ZSTD_buildFSETable_body_default(ZSTD_seqSymbol* dt,
            const short* normalizedCounter, unsigned maxSymbolValue,
            const U32* baseValue, const U8* nbAdditionalBits,
            unsigned tableLog, void* wksp, size_t wkspSize)
{
    ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue,
            baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
}

#if DYNAMIC_BMI2
BMI2_TARGET_ATTRIBUTE static void ZSTD_buildFSETable_body_bmi2(ZSTD_seqSymbol* dt,
            const short* normalizedCounter, unsigned maxSymbolValue,
            const U32* baseValue, const U8* nbAdditionalBits,
            unsigned tableLog, void* wksp, size_t wkspSize)
{
    ZSTD_buildFSETable_body(dt, normalizedCounter, maxSymbolValue,
            baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
}
#endif

void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
            const short* normalizedCounter, unsigned maxSymbolValue,
            const U32* baseValue, const U8* nbAdditionalBits,
            unsigned tableLog, void* wksp, size_t wkspSize, int bmi2)
{
#if DYNAMIC_BMI2
    if (bmi2) {
        ZSTD_buildFSETable_body_bmi2(dt, normalizedCounter, maxSymbolValue,
                baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
        return;
    }
#endif
    (void)bmi2;
    ZSTD_buildFSETable_body_default(dt, normalizedCounter, maxSymbolValue,
            baseValue, nbAdditionalBits, tableLog, wksp, wkspSize);
}


/*! ZSTD_buildSeqTable() :
 * @return : nb bytes read from src,
 *           or an error code if it fails */
static size_t ZSTD_buildSeqTable(ZSTD_seqSymbol* DTableSpace, const ZSTD_seqSymbol** DTablePtr,
                                 symbolEncodingType_e type, unsigned max, U32 maxLog,
                                 const void* src, size_t srcSize,
                                 const U32* baseValue, const U8* nbAdditionalBits,
                                 const ZSTD_seqSymbol* defaultTable, U32 flagRepeatTable,
                                 int ddictIsCold, int nbSeq, U32* wksp, size_t wkspSize,
                                 int bmi2)
{
    switch(type)
    {
    case set_rle :
        RETURN_ERROR_IF(!srcSize, srcSize_wrong, "");
        RETURN_ERROR_IF((*(const BYTE*)src) > max, corruption_detected, "");
        {   U32 const symbol = *(const BYTE*)src;
            U32 const baseline = baseValue[symbol];
            U8 const nbBits = nbAdditionalBits[symbol];
            ZSTD_buildSeqTable_rle(DTableSpace, baseline, nbBits);
        }
        *DTablePtr = DTableSpace;
        return 1;
    case set_basic :
        *DTablePtr = defaultTable;
        return 0;
    case set_repeat:
        RETURN_ERROR_IF(!flagRepeatTable, corruption_detected, "");
        /* prefetch FSE table if used */
        if (ddictIsCold && (nbSeq > 24 /* heuristic */)) {
            const void* const pStart = *DTablePtr;
            size_t const pSize = sizeof(ZSTD_seqSymbol) * (SEQSYMBOL_TABLE_SIZE(maxLog));
            PREFETCH_AREA(pStart, pSize);
        }
        return 0;
    case set_compressed :
        {   unsigned tableLog;
            S16 norm[MaxSeq+1];
            size_t const headerSize = FSE_readNCount(norm, &max, &tableLog, src, srcSize);
            RETURN_ERROR_IF(FSE_isError(headerSize), corruption_detected, "");
            RETURN_ERROR_IF(tableLog > maxLog, corruption_detected, "");
            ZSTD_buildFSETable(DTableSpace, norm, max, baseValue, nbAdditionalBits, tableLog, wksp, wkspSize, bmi2);
            *DTablePtr = DTableSpace;
            return headerSize;
        }
    default :
        assert(0);
        RETURN_ERROR(GENERIC, "impossible");
    }
}

size_t ZSTD_decodeSeqHeaders(ZSTD_DCtx* dctx, int* nbSeqPtr,
                             const void* src, size_t srcSize)
{
    const BYTE* const istart = (const BYTE*)src;
    const BYTE* const iend = istart + srcSize;
    const BYTE* ip = istart;
    int nbSeq;
    DEBUGLOG(5, "ZSTD_decodeSeqHeaders");

    /* check */
    RETURN_ERROR_IF(srcSize < MIN_SEQUENCES_SIZE, srcSize_wrong, "");

    /* SeqHead */
    nbSeq = *ip++;
    if (nbSeq > 0x7F) {
        if (nbSeq == 0xFF) {
            RETURN_ERROR_IF(ip+2 > iend, srcSize_wrong, "");
            nbSeq = MEM_readLE16(ip) + LONGNBSEQ;
            ip+=2;
        } else {
            RETURN_ERROR_IF(ip >= iend, srcSize_wrong, "");
            nbSeq = ((nbSeq-0x80)<<8) + *ip++;
        }
    }
    *nbSeqPtr = nbSeq;

    if (nbSeq == 0) {
        /* No sequence : section ends immediately */
        RETURN_ERROR_IF(ip != iend, corruption_detected,
            "extraneous data present in the Sequences section");
        return (size_t)(ip - istart);
    }

    /* FSE table descriptors */
    RETURN_ERROR_IF(ip+1 > iend, srcSize_wrong, ""); /* minimum possible size: 1 byte for symbol encoding types */
    RETURN_ERROR_IF(*ip & 3, corruption_detected, ""); /* The last field, Reserved, must be all-zeroes. */
    {   symbolEncodingType_e const LLtype = (symbolEncodingType_e)(*ip >> 6);
        symbolEncodingType_e const OFtype = (symbolEncodingType_e)((*ip >> 4) & 3);
        symbolEncodingType_e const MLtype = (symbolEncodingType_e)((*ip >> 2) & 3);
        ip++;

        /* Build DTables */
        {   size_t const llhSize = ZSTD_buildSeqTable(dctx->entropy.LLTable, &dctx->LLTptr,
                                                      LLtype, MaxLL, LLFSELog,
                                                      ip, iend-ip,
                                                      LL_base, LL_bits,
                                                      LL_defaultDTable, dctx->fseEntropy,
                                                      dctx->ddictIsCold, nbSeq,
                                                      dctx->workspace, sizeof(dctx->workspace),
                                                      ZSTD_DCtx_get_bmi2(dctx));
            RETURN_ERROR_IF(ZSTD_isError(llhSize), corruption_detected, "ZSTD_buildSeqTable failed");
            ip += llhSize;
        }

        {   size_t const ofhSize = ZSTD_buildSeqTable(dctx->entropy.OFTable, &dctx->OFTptr,
                                                      OFtype, MaxOff, OffFSELog,
                                                      ip, iend-ip,
                                                      OF_base, OF_bits,
                                                      OF_defaultDTable, dctx->fseEntropy,
                                                      dctx->ddictIsCold, nbSeq,
                                                      dctx->workspace, sizeof(dctx->workspace),
                                                      ZSTD_DCtx_get_bmi2(dctx));
            RETURN_ERROR_IF(ZSTD_isError(ofhSize), corruption_detected, "ZSTD_buildSeqTable failed");
            ip += ofhSize;
        }

        {   size_t const mlhSize = ZSTD_buildSeqTable(dctx->entropy.MLTable, &dctx->MLTptr,
                                                      MLtype, MaxML, MLFSELog,
                                                      ip, iend-ip,
                                                      ML_base, ML_bits,
                                                      ML_defaultDTable, dctx->fseEntropy,
                                                      dctx->ddictIsCold, nbSeq,
                                                      dctx->workspace, sizeof(dctx->workspace),
                                                      ZSTD_DCtx_get_bmi2(dctx));
            RETURN_ERROR_IF(ZSTD_isError(mlhSize), corruption_detected, "ZSTD_buildSeqTable failed");
            ip += mlhSize;
        }
    }

    return ip-istart;
}


typedef struct {
    size_t litLength;
    size_t matchLength;
    size_t offset;
} seq_t;

typedef struct {
    size_t state;
    const ZSTD_seqSymbol* table;
} ZSTD_fseState;

typedef struct {
    BIT_DStream_t DStream;
    ZSTD_fseState stateLL;
    ZSTD_fseState stateOffb;
    ZSTD_fseState stateML;
    size_t prevOffset[ZSTD_REP_NUM];
} seqState_t;

/*! ZSTD_overlapCopy8() :
 *  Copies 8 bytes from ip to op and updates op and ip where ip <= op.
 *  If the offset is < 8 then the offset is spread to at least 8 bytes.
 *
 *  Precondition: *ip <= *op
 *  Postcondition: *op - *op >= 8
 */
HINT_INLINE void ZSTD_overlapCopy8(BYTE** op, BYTE const** ip, size_t offset) {
    assert(*ip <= *op);
    if (offset < 8) {
        /* close range match, overlap */
        static const U32 dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };   /* added */
        static const int dec64table[] = { 8, 8, 8, 7, 8, 9,10,11 };   /* subtracted */
        int const sub2 = dec64table[offset];
        (*op)[0] = (*ip)[0];
        (*op)[1] = (*ip)[1];
        (*op)[2] = (*ip)[2];
        (*op)[3] = (*ip)[3];
        *ip += dec32table[offset];
        ZSTD_copy4(*op+4, *ip);
        *ip -= sub2;
    } else {
        ZSTD_copy8(*op, *ip);
    }
    *ip += 8;
    *op += 8;
    assert(*op - *ip >= 8);
}

/*! ZSTD_safecopy() :
 *  Specialized version of memcpy() that is allowed to READ up to WILDCOPY_OVERLENGTH past the input buffer
 *  and write up to 16 bytes past oend_w (op >= oend_w is allowed).
 *  This function is only called in the uncommon case where the sequence is near the end of the block. It
 *  should be fast for a single long sequence, but can be slow for several short sequences.
 *
 *  @param ovtype controls the overlap detection
 *         - ZSTD_no_overlap: The source and destination are guaranteed to be at least WILDCOPY_VECLEN bytes apart.
 *         - ZSTD_overlap_src_before_dst: The src and dst may overlap and may be any distance apart.
 *           The src buffer must be before the dst buffer.
 */
static void ZSTD_safecopy(BYTE* op, const BYTE* const oend_w, BYTE const* ip, ptrdiff_t length, ZSTD_overlap_e ovtype) {
    ptrdiff_t const diff = op - ip;
    BYTE* const oend = op + length;

    assert((ovtype == ZSTD_no_overlap && (diff <= -8 || diff >= 8 || op >= oend_w)) ||
           (ovtype == ZSTD_overlap_src_before_dst && diff >= 0));

    if (length < 8) {
        /* Handle short lengths. */
        while (op < oend) *op++ = *ip++;
        return;
    }
    if (ovtype == ZSTD_overlap_src_before_dst) {
        /* Copy 8 bytes and ensure the offset >= 8 when there can be overlap. */
        assert(length >= 8);
        ZSTD_overlapCopy8(&op, &ip, diff);
        length -= 8;
        assert(op - ip >= 8);
        assert(op <= oend);
    }

    if (oend <= oend_w) {
        /* No risk of overwrite. */
        ZSTD_wildcopy(op, ip, length, ovtype);
        return;
    }
    if (op <= oend_w) {
        /* Wildcopy until we get close to the end. */
        assert(oend > oend_w);
        ZSTD_wildcopy(op, ip, oend_w - op, ovtype);
        ip += oend_w - op;
        op += oend_w - op;
    }
    /* Handle the leftovers. */
    while (op < oend) *op++ = *ip++;
}

/* ZSTD_safecopyDstBeforeSrc():
 * This version allows overlap with dst before src, or handles the non-overlap case with dst after src
 * Kept separate from more common ZSTD_safecopy case to avoid performance impact to the safecopy common case */
static void ZSTD_safecopyDstBeforeSrc(BYTE* op, const BYTE* ip, ptrdiff_t length) {
    ptrdiff_t const diff = op - ip;
    BYTE* const oend = op + length;

    if (length < 8 || diff > -8) {
        /* Handle short lengths, close overlaps, and dst not before src. */
        while (op < oend) *op++ = *ip++;
        return;
    }

    if (op <= oend - WILDCOPY_OVERLENGTH && diff < -WILDCOPY_VECLEN) {
        ZSTD_wildcopy(op, ip, oend - WILDCOPY_OVERLENGTH - op, ZSTD_no_overlap);
        ip += oend - WILDCOPY_OVERLENGTH - op;
        op += oend - WILDCOPY_OVERLENGTH - op;
    }

    /* Handle the leftovers. */
    while (op < oend) *op++ = *ip++;
}

/* ZSTD_execSequenceEnd():
 * This version handles cases that are near the end of the output buffer. It requires
 * more careful checks to make sure there is no overflow. By separating out these hard
 * and unlikely cases, we can speed up the common cases.
 *
 * NOTE: This function needs to be fast for a single long sequence, but doesn't need
 * to be optimized for many small sequences, since those fall into ZSTD_execSequence().
 */
FORCE_NOINLINE
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
size_t ZSTD_execSequenceEnd(BYTE* op,
    BYTE* const oend, seq_t sequence,
    const BYTE** litPtr, const BYTE* const litLimit,
    const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
{
    BYTE* const oLitEnd = op + sequence.litLength;
    size_t const sequenceLength = sequence.litLength + sequence.matchLength;
    const BYTE* const iLitEnd = *litPtr + sequence.litLength;
    const BYTE* match = oLitEnd - sequence.offset;
    BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;

    /* bounds checks : careful of address space overflow in 32-bit mode */
    RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer");
    RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer");
    assert(op < op + sequenceLength);
    assert(oLitEnd < op + sequenceLength);

    /* copy literals */
    ZSTD_safecopy(op, oend_w, *litPtr, sequence.litLength, ZSTD_no_overlap);
    op = oLitEnd;
    *litPtr = iLitEnd;

    /* copy Match */
    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
        /* offset beyond prefix */
        RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, "");
        match = dictEnd - (prefixStart - match);
        if (match + sequence.matchLength <= dictEnd) {
            ZSTD_memmove(oLitEnd, match, sequence.matchLength);
            return sequenceLength;
        }
        /* span extDict & currentPrefixSegment */
        {   size_t const length1 = dictEnd - match;
        ZSTD_memmove(oLitEnd, match, length1);
        op = oLitEnd + length1;
        sequence.matchLength -= length1;
        match = prefixStart;
        }
    }
    ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
    return sequenceLength;
}

/* ZSTD_execSequenceEndSplitLitBuffer():
 * This version is intended to be used during instances where the litBuffer is still split.  It is kept separate to avoid performance impact for the good case.
 */
FORCE_NOINLINE
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
size_t ZSTD_execSequenceEndSplitLitBuffer(BYTE* op,
    BYTE* const oend, const BYTE* const oend_w, seq_t sequence,
    const BYTE** litPtr, const BYTE* const litLimit,
    const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
{
    BYTE* const oLitEnd = op + sequence.litLength;
    size_t const sequenceLength = sequence.litLength + sequence.matchLength;
    const BYTE* const iLitEnd = *litPtr + sequence.litLength;
    const BYTE* match = oLitEnd - sequence.offset;


    /* bounds checks : careful of address space overflow in 32-bit mode */
    RETURN_ERROR_IF(sequenceLength > (size_t)(oend - op), dstSize_tooSmall, "last match must fit within dstBuffer");
    RETURN_ERROR_IF(sequence.litLength > (size_t)(litLimit - *litPtr), corruption_detected, "try to read beyond literal buffer");
    assert(op < op + sequenceLength);
    assert(oLitEnd < op + sequenceLength);

    /* copy literals */
    RETURN_ERROR_IF(op > *litPtr && op < *litPtr + sequence.litLength, dstSize_tooSmall, "output should not catch up to and overwrite literal buffer");
    ZSTD_safecopyDstBeforeSrc(op, *litPtr, sequence.litLength);
    op = oLitEnd;
    *litPtr = iLitEnd;

    /* copy Match */
    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
        /* offset beyond prefix */
        RETURN_ERROR_IF(sequence.offset > (size_t)(oLitEnd - virtualStart), corruption_detected, "");
        match = dictEnd - (prefixStart - match);
        if (match + sequence.matchLength <= dictEnd) {
            ZSTD_memmove(oLitEnd, match, sequence.matchLength);
            return sequenceLength;
        }
        /* span extDict & currentPrefixSegment */
        {   size_t const length1 = dictEnd - match;
        ZSTD_memmove(oLitEnd, match, length1);
        op = oLitEnd + length1;
        sequence.matchLength -= length1;
        match = prefixStart;
        }
    }
    ZSTD_safecopy(op, oend_w, match, sequence.matchLength, ZSTD_overlap_src_before_dst);
    return sequenceLength;
}

HINT_INLINE
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
size_t ZSTD_execSequence(BYTE* op,
    BYTE* const oend, seq_t sequence,
    const BYTE** litPtr, const BYTE* const litLimit,
    const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
{
    BYTE* const oLitEnd = op + sequence.litLength;
    size_t const sequenceLength = sequence.litLength + sequence.matchLength;
    BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
    BYTE* const oend_w = oend - WILDCOPY_OVERLENGTH;   /* risk : address space underflow on oend=NULL */
    const BYTE* const iLitEnd = *litPtr + sequence.litLength;
    const BYTE* match = oLitEnd - sequence.offset;

    assert(op != NULL /* Precondition */);
    assert(oend_w < oend /* No underflow */);

#if defined(__aarch64__)
    /* prefetch sequence starting from match that will be used for copy later */
    PREFETCH_L1(match);
#endif
    /* Handle edge cases in a slow path:
     *   - Read beyond end of literals
     *   - Match end is within WILDCOPY_OVERLIMIT of oend
     *   - 32-bit mode and the match length overflows
     */
    if (UNLIKELY(
        iLitEnd > litLimit ||
        oMatchEnd > oend_w ||
        (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH)))
        return ZSTD_execSequenceEnd(op, oend, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);

    /* Assumptions (everything else goes into ZSTD_execSequenceEnd()) */
    assert(op <= oLitEnd /* No overflow */);
    assert(oLitEnd < oMatchEnd /* Non-zero match & no overflow */);
    assert(oMatchEnd <= oend /* No underflow */);
    assert(iLitEnd <= litLimit /* Literal length is in bounds */);
    assert(oLitEnd <= oend_w /* Can wildcopy literals */);
    assert(oMatchEnd <= oend_w /* Can wildcopy matches */);

    /* Copy Literals:
     * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9.
     * We likely don't need the full 32-byte wildcopy.
     */
    assert(WILDCOPY_OVERLENGTH >= 16);
    ZSTD_copy16(op, (*litPtr));
    if (UNLIKELY(sequence.litLength > 16)) {
        ZSTD_wildcopy(op + 16, (*litPtr) + 16, sequence.litLength - 16, ZSTD_no_overlap);
    }
    op = oLitEnd;
    *litPtr = iLitEnd;   /* update for next sequence */

    /* Copy Match */
    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
        /* offset beyond prefix -> go into extDict */
        RETURN_ERROR_IF(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, "");
        match = dictEnd + (match - prefixStart);
        if (match + sequence.matchLength <= dictEnd) {
            ZSTD_memmove(oLitEnd, match, sequence.matchLength);
            return sequenceLength;
        }
        /* span extDict & currentPrefixSegment */
        {   size_t const length1 = dictEnd - match;
        ZSTD_memmove(oLitEnd, match, length1);
        op = oLitEnd + length1;
        sequence.matchLength -= length1;
        match = prefixStart;
        }
    }
    /* Match within prefix of 1 or more bytes */
    assert(op <= oMatchEnd);
    assert(oMatchEnd <= oend_w);
    assert(match >= prefixStart);
    assert(sequence.matchLength >= 1);

    /* Nearly all offsets are >= WILDCOPY_VECLEN bytes, which means we can use wildcopy
     * without overlap checking.
     */
    if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) {
        /* We bet on a full wildcopy for matches, since we expect matches to be
         * longer than literals (in general). In silesia, ~10% of matches are longer
         * than 16 bytes.
         */
        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
        return sequenceLength;
    }
    assert(sequence.offset < WILDCOPY_VECLEN);

    /* Copy 8 bytes and spread the offset to be >= 8. */
    ZSTD_overlapCopy8(&op, &match, sequence.offset);

    /* If the match length is > 8 bytes, then continue with the wildcopy. */
    if (sequence.matchLength > 8) {
        assert(op < oMatchEnd);
        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength - 8, ZSTD_overlap_src_before_dst);
    }
    return sequenceLength;
}

HINT_INLINE
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
size_t ZSTD_execSequenceSplitLitBuffer(BYTE* op,
    BYTE* const oend, const BYTE* const oend_w, seq_t sequence,
    const BYTE** litPtr, const BYTE* const litLimit,
    const BYTE* const prefixStart, const BYTE* const virtualStart, const BYTE* const dictEnd)
{
    BYTE* const oLitEnd = op + sequence.litLength;
    size_t const sequenceLength = sequence.litLength + sequence.matchLength;
    BYTE* const oMatchEnd = op + sequenceLength;   /* risk : address space overflow (32-bits) */
    const BYTE* const iLitEnd = *litPtr + sequence.litLength;
    const BYTE* match = oLitEnd - sequence.offset;

    assert(op != NULL /* Precondition */);
    assert(oend_w < oend /* No underflow */);
    /* Handle edge cases in a slow path:
     *   - Read beyond end of literals
     *   - Match end is within WILDCOPY_OVERLIMIT of oend
     *   - 32-bit mode and the match length overflows
     */
    if (UNLIKELY(
            iLitEnd > litLimit ||
            oMatchEnd > oend_w ||
            (MEM_32bits() && (size_t)(oend - op) < sequenceLength + WILDCOPY_OVERLENGTH)))
        return ZSTD_execSequenceEndSplitLitBuffer(op, oend, oend_w, sequence, litPtr, litLimit, prefixStart, virtualStart, dictEnd);

    /* Assumptions (everything else goes into ZSTD_execSequenceEnd()) */
    assert(op <= oLitEnd /* No overflow */);
    assert(oLitEnd < oMatchEnd /* Non-zero match & no overflow */);
    assert(oMatchEnd <= oend /* No underflow */);
    assert(iLitEnd <= litLimit /* Literal length is in bounds */);
    assert(oLitEnd <= oend_w /* Can wildcopy literals */);
    assert(oMatchEnd <= oend_w /* Can wildcopy matches */);

    /* Copy Literals:
     * Split out litLength <= 16 since it is nearly always true. +1.6% on gcc-9.
     * We likely don't need the full 32-byte wildcopy.
     */
    assert(WILDCOPY_OVERLENGTH >= 16);
    ZSTD_copy16(op, (*litPtr));
    if (UNLIKELY(sequence.litLength > 16)) {
        ZSTD_wildcopy(op+16, (*litPtr)+16, sequence.litLength-16, ZSTD_no_overlap);
    }
    op = oLitEnd;
    *litPtr = iLitEnd;   /* update for next sequence */

    /* Copy Match */
    if (sequence.offset > (size_t)(oLitEnd - prefixStart)) {
        /* offset beyond prefix -> go into extDict */
        RETURN_ERROR_IF(UNLIKELY(sequence.offset > (size_t)(oLitEnd - virtualStart)), corruption_detected, "");
        match = dictEnd + (match - prefixStart);
        if (match + sequence.matchLength <= dictEnd) {
            ZSTD_memmove(oLitEnd, match, sequence.matchLength);
            return sequenceLength;
        }
        /* span extDict & currentPrefixSegment */
        {   size_t const length1 = dictEnd - match;
            ZSTD_memmove(oLitEnd, match, length1);
            op = oLitEnd + length1;
            sequence.matchLength -= length1;
            match = prefixStart;
    }   }
    /* Match within prefix of 1 or more bytes */
    assert(op <= oMatchEnd);
    assert(oMatchEnd <= oend_w);
    assert(match >= prefixStart);
    assert(sequence.matchLength >= 1);

    /* Nearly all offsets are >= WILDCOPY_VECLEN bytes, which means we can use wildcopy
     * without overlap checking.
     */
    if (LIKELY(sequence.offset >= WILDCOPY_VECLEN)) {
        /* We bet on a full wildcopy for matches, since we expect matches to be
         * longer than literals (in general). In silesia, ~10% of matches are longer
         * than 16 bytes.
         */
        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength, ZSTD_no_overlap);
        return sequenceLength;
    }
    assert(sequence.offset < WILDCOPY_VECLEN);

    /* Copy 8 bytes and spread the offset to be >= 8. */
    ZSTD_overlapCopy8(&op, &match, sequence.offset);

    /* If the match length is > 8 bytes, then continue with the wildcopy. */
    if (sequence.matchLength > 8) {
        assert(op < oMatchEnd);
        ZSTD_wildcopy(op, match, (ptrdiff_t)sequence.matchLength-8, ZSTD_overlap_src_before_dst);
    }
    return sequenceLength;
}


static void
ZSTD_initFseState(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, const ZSTD_seqSymbol* dt)
{
    const void* ptr = dt;
    const ZSTD_seqSymbol_header* const DTableH = (const ZSTD_seqSymbol_header*)ptr;
    DStatePtr->state = BIT_readBits(bitD, DTableH->tableLog);
    DEBUGLOG(6, "ZSTD_initFseState : val=%u using %u bits",
                (U32)DStatePtr->state, DTableH->tableLog);
    BIT_reloadDStream(bitD);
    DStatePtr->table = dt + 1;
}

FORCE_INLINE_TEMPLATE void
ZSTD_updateFseStateWithDInfo(ZSTD_fseState* DStatePtr, BIT_DStream_t* bitD, U16 nextState, U32 nbBits)
{
    size_t const lowBits = BIT_readBits(bitD, nbBits);
    DStatePtr->state = nextState + lowBits;
}

/* We need to add at most (ZSTD_WINDOWLOG_MAX_32 - 1) bits to read the maximum
 * offset bits. But we can only read at most STREAM_ACCUMULATOR_MIN_32
 * bits before reloading. This value is the maximum number of bytes we read
 * after reloading when we are decoding long offsets.
 */
#define LONG_OFFSETS_MAX_EXTRA_BITS_32                       \
    (ZSTD_WINDOWLOG_MAX_32 > STREAM_ACCUMULATOR_MIN_32       \
        ? ZSTD_WINDOWLOG_MAX_32 - STREAM_ACCUMULATOR_MIN_32  \
        : 0)

typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;

/**
 * ZSTD_decodeSequence():
 * @p longOffsets : tells the decoder to reload more bit while decoding large offsets
 *                  only used in 32-bit mode
 * @return : Sequence (litL + matchL + offset)
 */
FORCE_INLINE_TEMPLATE seq_t
ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, const int isLastSeq)
{
    seq_t seq;
    /*
     * ZSTD_seqSymbol is a 64 bits wide structure.
     * It can be loaded in one operation
     * and its fields extracted by simply shifting or bit-extracting on aarch64.
     * GCC doesn't recognize this and generates more unnecessary ldr/ldrb/ldrh
     * operations that cause performance drop. This can be avoided by using this
     * ZSTD_memcpy hack.
     */
#if defined(__aarch64__) && (defined(__GNUC__) && !defined(__clang__))
    ZSTD_seqSymbol llDInfoS, mlDInfoS, ofDInfoS;
    ZSTD_seqSymbol* const llDInfo = &llDInfoS;
    ZSTD_seqSymbol* const mlDInfo = &mlDInfoS;
    ZSTD_seqSymbol* const ofDInfo = &ofDInfoS;
    ZSTD_memcpy(llDInfo, seqState->stateLL.table + seqState->stateLL.state, sizeof(ZSTD_seqSymbol));
    ZSTD_memcpy(mlDInfo, seqState->stateML.table + seqState->stateML.state, sizeof(ZSTD_seqSymbol));
    ZSTD_memcpy(ofDInfo, seqState->stateOffb.table + seqState->stateOffb.state, sizeof(ZSTD_seqSymbol));
#else
    const ZSTD_seqSymbol* const llDInfo = seqState->stateLL.table + seqState->stateLL.state;
    const ZSTD_seqSymbol* const mlDInfo = seqState->stateML.table + seqState->stateML.state;
    const ZSTD_seqSymbol* const ofDInfo = seqState->stateOffb.table + seqState->stateOffb.state;
#endif
    seq.matchLength = mlDInfo->baseValue;
    seq.litLength = llDInfo->baseValue;
    {   U32 const ofBase = ofDInfo->baseValue;
        BYTE const llBits = llDInfo->nbAdditionalBits;
        BYTE const mlBits = mlDInfo->nbAdditionalBits;
        BYTE const ofBits = ofDInfo->nbAdditionalBits;
        BYTE const totalBits = llBits+mlBits+ofBits;

        U16 const llNext = llDInfo->nextState;
        U16 const mlNext = mlDInfo->nextState;
        U16 const ofNext = ofDInfo->nextState;
        U32 const llnbBits = llDInfo->nbBits;
        U32 const mlnbBits = mlDInfo->nbBits;
        U32 const ofnbBits = ofDInfo->nbBits;

        assert(llBits <= MaxLLBits);
        assert(mlBits <= MaxMLBits);
        assert(ofBits <= MaxOff);
        /*
         * As gcc has better branch and block analyzers, sometimes it is only
         * valuable to mark likeliness for clang, it gives around 3-4% of
         * performance.
         */

        /* sequence */
        {   size_t offset;
            if (ofBits > 1) {
                ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
                ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
                ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 > LONG_OFFSETS_MAX_EXTRA_BITS_32);
                ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 - LONG_OFFSETS_MAX_EXTRA_BITS_32 >= MaxMLBits);
                if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
                    /* Always read extra bits, this keeps the logic simple,
                     * avoids branches, and avoids accidentally reading 0 bits.
                     */
                    U32 const extraBits = LONG_OFFSETS_MAX_EXTRA_BITS_32;
                    offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
                    BIT_reloadDStream(&seqState->DStream);
                    offset += BIT_readBitsFast(&seqState->DStream, extraBits);
                } else {
                    offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/);   /* <=  (ZSTD_WINDOWLOG_MAX-1) bits */
                    if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
                }
                seqState->prevOffset[2] = seqState->prevOffset[1];
                seqState->prevOffset[1] = seqState->prevOffset[0];
                seqState->prevOffset[0] = offset;
            } else {
                U32 const ll0 = (llDInfo->baseValue == 0);
                if (LIKELY((ofBits == 0))) {
                    offset = seqState->prevOffset[ll0];
                    seqState->prevOffset[1] = seqState->prevOffset[!ll0];
                    seqState->prevOffset[0] = offset;
                } else {
                    offset = ofBase + ll0 + BIT_readBitsFast(&seqState->DStream, 1);
                    {   size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
                        temp -= !temp; /* 0 is not valid: input corrupted => force offset to -1 => corruption detected at execSequence */
                        if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
                        seqState->prevOffset[1] = seqState->prevOffset[0];
                        seqState->prevOffset[0] = offset = temp;
            }   }   }
            seq.offset = offset;
        }

        if (mlBits > 0)
            seq.matchLength += BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/);

        if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
            BIT_reloadDStream(&seqState->DStream);
        if (MEM_64bits() && UNLIKELY(totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
            BIT_reloadDStream(&seqState->DStream);
        /* Ensure there are enough bits to read the rest of data in 64-bit mode. */
        ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);

        if (llBits > 0)
            seq.litLength += BIT_readBitsFast(&seqState->DStream, llBits/*>0*/);

        if (MEM_32bits())
            BIT_reloadDStream(&seqState->DStream);

        DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
                    (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);

        if (!isLastSeq) {
            /* don't update FSE state for last Sequence */
            ZSTD_updateFseStateWithDInfo(&seqState->stateLL, &seqState->DStream, llNext, llnbBits);    /* <=  9 bits */
            ZSTD_updateFseStateWithDInfo(&seqState->stateML, &seqState->DStream, mlNext, mlnbBits);    /* <=  9 bits */
            if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
            ZSTD_updateFseStateWithDInfo(&seqState->stateOffb, &seqState->DStream, ofNext, ofnbBits);  /* <=  8 bits */
            BIT_reloadDStream(&seqState->DStream);
        }
    }

    return seq;
}

#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
#if DEBUGLEVEL >= 1
static int ZSTD_dictionaryIsActive(ZSTD_DCtx const* dctx, BYTE const* prefixStart, BYTE const* oLitEnd)
{
    size_t const windowSize = dctx->fParams.windowSize;
    /* No dictionary used. */
    if (dctx->dictContentEndForFuzzing == NULL) return 0;
    /* Dictionary is our prefix. */
    if (prefixStart == dctx->dictContentBeginForFuzzing) return 1;
    /* Dictionary is not our ext-dict. */
    if (dctx->dictEnd != dctx->dictContentEndForFuzzing) return 0;
    /* Dictionary is not within our window size. */
    if ((size_t)(oLitEnd - prefixStart) >= windowSize) return 0;
    /* Dictionary is active. */
    return 1;
}
#endif

static void ZSTD_assertValidSequence(
        ZSTD_DCtx const* dctx,
        BYTE const* op, BYTE const* oend,
        seq_t const seq,
        BYTE const* prefixStart, BYTE const* virtualStart)
{
#if DEBUGLEVEL >= 1
    if (dctx->isFrameDecompression) {
        size_t const windowSize = dctx->fParams.windowSize;
        size_t const sequenceSize = seq.litLength + seq.matchLength;
        BYTE const* const oLitEnd = op + seq.litLength;
        DEBUGLOG(6, "Checking sequence: litL=%u matchL=%u offset=%u",
                (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
        assert(op <= oend);
        assert((size_t)(oend - op) >= sequenceSize);
        assert(sequenceSize <= ZSTD_blockSizeMax(dctx));
        if (ZSTD_dictionaryIsActive(dctx, prefixStart, oLitEnd)) {
            size_t const dictSize = (size_t)((char const*)dctx->dictContentEndForFuzzing - (char const*)dctx->dictContentBeginForFuzzing);
            /* Offset must be within the dictionary. */
            assert(seq.offset <= (size_t)(oLitEnd - virtualStart));
            assert(seq.offset <= windowSize + dictSize);
        } else {
            /* Offset must be within our window. */
            assert(seq.offset <= windowSize);
        }
    }
#else
    (void)dctx, (void)op, (void)oend, (void)seq, (void)prefixStart, (void)virtualStart;
#endif
}
#endif

#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG


FORCE_INLINE_TEMPLATE size_t
DONT_VECTORIZE
ZSTD_decompressSequences_bodySplitLitBuffer( ZSTD_DCtx* dctx,
                               void* dst, size_t maxDstSize,
                         const void* seqStart, size_t seqSize, int nbSeq,
                         const ZSTD_longOffset_e isLongOffset)
{
    const BYTE* ip = (const BYTE*)seqStart;
    const BYTE* const iend = ip + seqSize;
    BYTE* const ostart = (BYTE*)dst;
    BYTE* const oend = ZSTD_maybeNullPtrAdd(ostart, maxDstSize);
    BYTE* op = ostart;
    const BYTE* litPtr = dctx->litPtr;
    const BYTE* litBufferEnd = dctx->litBufferEnd;
    const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
    const BYTE* const vBase = (const BYTE*) (dctx->virtualStart);
    const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);
    DEBUGLOG(5, "ZSTD_decompressSequences_bodySplitLitBuffer (%i seqs)", nbSeq);

    /* Literals are split between internal buffer & output buffer */
    if (nbSeq) {
        seqState_t seqState;
        dctx->fseEntropy = 1;
        { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
        RETURN_ERROR_IF(
            ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
            corruption_detected, "");
        ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
        ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
        ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
        assert(dst != NULL);

        ZSTD_STATIC_ASSERT(
                BIT_DStream_unfinished < BIT_DStream_completed &&
                BIT_DStream_endOfBuffer < BIT_DStream_completed &&
                BIT_DStream_completed < BIT_DStream_overflow);

        /* decompress without overrunning litPtr begins */
        {   seq_t sequence = {0,0,0};  /* some static analyzer believe that @sequence is not initialized (it necessarily is, since for(;;) loop as at least one iteration) */
            /* Align the decompression loop to 32 + 16 bytes.
                *
                * zstd compiled with gcc-9 on an Intel i9-9900k shows 10% decompression
                * speed swings based on the alignment of the decompression loop. This
                * performance swing is caused by parts of the decompression loop falling
                * out of the DSB. The entire decompression loop should fit in the DSB,
                * when it can't we get much worse performance. You can measure if you've
                * hit the good case or the bad case with this perf command for some
                * compressed file test.zst:
                *
                *   perf stat -e cycles -e instructions -e idq.all_dsb_cycles_any_uops \
                *             -e idq.all_mite_cycles_any_uops -- ./zstd -tq test.zst
                *
                * If you see most cycles served out of the MITE you've hit the bad case.
                * If you see most cycles served out of the DSB you've hit the good case.
                * If it is pretty even then you may be in an okay case.
                *
                * This issue has been reproduced on the following CPUs:
                *   - Kabylake: Macbook Pro (15-inch, 2019) 2.4 GHz Intel Core i9
                *               Use Instruments->Counters to get DSB/MITE cycles.
                *               I never got performance swings, but I was able to
                *               go from the good case of mostly DSB to half of the
                *               cycles served from MITE.
                *   - Coffeelake: Intel i9-9900k
                *   - Coffeelake: Intel i7-9700k
                *
                * I haven't been able to reproduce the instability or DSB misses on any
                * of the following CPUS:
                *   - Haswell
                *   - Broadwell: Intel(R) Xeon(R) CPU E5-2680 v4 @ 2.40GH
                *   - Skylake
                *
                * Alignment is done for each of the three major decompression loops:
                *   - ZSTD_decompressSequences_bodySplitLitBuffer - presplit section of the literal buffer
                *   - ZSTD_decompressSequences_bodySplitLitBuffer - postsplit section of the literal buffer
                *   - ZSTD_decompressSequences_body
                * Alignment choices are made to minimize large swings on bad cases and influence on performance
                * from changes external to this code, rather than to overoptimize on the current commit.
                *
                * If you are seeing performance stability this script can help test.
                * It tests on 4 commits in zstd where I saw performance change.
                *
                *   https://gist.github.com/terrelln/9889fc06a423fd5ca6e99351564473f4
                */
#if defined(__GNUC__) && defined(__x86_64__)
            __asm__(".p2align 6");
#  if __GNUC__ >= 7
            /* good for gcc-7, gcc-9, and gcc-11 */
            __asm__("nop");
            __asm__(".p2align 5");
            __asm__("nop");
            __asm__(".p2align 4");
#    if __GNUC__ == 8 || __GNUC__ == 10
            /* good for gcc-8 and gcc-10 */
            __asm__("nop");
            __asm__(".p2align 3");
#    endif
#  endif
#endif

            /* Handle the initial state where litBuffer is currently split between dst and litExtraBuffer */
            for ( ; nbSeq; nbSeq--) {
                sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
                if (litPtr + sequence.litLength > dctx->litBufferEnd) break;
                {   size_t const oneSeqSize = ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequence.litLength - WILDCOPY_OVERLENGTH, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                    assert(!ZSTD_isError(oneSeqSize));
                    ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
#endif
                    if (UNLIKELY(ZSTD_isError(oneSeqSize)))
                        return oneSeqSize;
                    DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
                    op += oneSeqSize;
            }   }
            DEBUGLOG(6, "reached: (litPtr + sequence.litLength > dctx->litBufferEnd)");

            /* If there are more sequences, they will need to read literals from litExtraBuffer; copy over the remainder from dst and update litPtr and litEnd */
            if (nbSeq > 0) {
                const size_t leftoverLit = dctx->litBufferEnd - litPtr;
                DEBUGLOG(6, "There are %i sequences left, and %zu/%zu literals left in buffer", nbSeq, leftoverLit, sequence.litLength);
                if (leftoverLit) {
                    RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
                    ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
                    sequence.litLength -= leftoverLit;
                    op += leftoverLit;
                }
                litPtr = dctx->litExtraBuffer;
                litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
                dctx->litBufferLocation = ZSTD_not_in_dst;
                {   size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                    assert(!ZSTD_isError(oneSeqSize));
                    ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
#endif
                    if (UNLIKELY(ZSTD_isError(oneSeqSize)))
                        return oneSeqSize;
                    DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
                    op += oneSeqSize;
                }
                nbSeq--;
            }
        }

        if (nbSeq > 0) {
            /* there is remaining lit from extra buffer */

#if defined(__GNUC__) && defined(__x86_64__)
            __asm__(".p2align 6");
            __asm__("nop");
#  if __GNUC__ != 7
            /* worse for gcc-7 better for gcc-8, gcc-9, and gcc-10 and clang */
            __asm__(".p2align 4");
            __asm__("nop");
            __asm__(".p2align 3");
#  elif __GNUC__ >= 11
            __asm__(".p2align 3");
#  else
            __asm__(".p2align 5");
            __asm__("nop");
            __asm__(".p2align 3");
#  endif
#endif

            for ( ; nbSeq ; nbSeq--) {
                seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
                size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                assert(!ZSTD_isError(oneSeqSize));
                ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
#endif
                if (UNLIKELY(ZSTD_isError(oneSeqSize)))
                    return oneSeqSize;
                DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
                op += oneSeqSize;
            }
        }

        /* check if reached exact end */
        DEBUGLOG(5, "ZSTD_decompressSequences_bodySplitLitBuffer: after decode loop, remaining nbSeq : %i", nbSeq);
        RETURN_ERROR_IF(nbSeq, corruption_detected, "");
        DEBUGLOG(5, "bitStream : start=%p, ptr=%p, bitsConsumed=%u", seqState.DStream.start, seqState.DStream.ptr, seqState.DStream.bitsConsumed);
        RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");
        /* save reps for next block */
        { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
    }

    /* last literal segment */
    if (dctx->litBufferLocation == ZSTD_split) {
        /* split hasn't been reached yet, first get dst then copy litExtraBuffer */
        size_t const lastLLSize = (size_t)(litBufferEnd - litPtr);
        DEBUGLOG(6, "copy last literals from segment : %u", (U32)lastLLSize);
        RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, "");
        if (op != NULL) {
            ZSTD_memmove(op, litPtr, lastLLSize);
            op += lastLLSize;
        }
        litPtr = dctx->litExtraBuffer;
        litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
        dctx->litBufferLocation = ZSTD_not_in_dst;
    }
    /* copy last literals from internal buffer */
    {   size_t const lastLLSize = (size_t)(litBufferEnd - litPtr);
        DEBUGLOG(6, "copy last literals from internal buffer : %u", (U32)lastLLSize);
        RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
        if (op != NULL) {
            ZSTD_memcpy(op, litPtr, lastLLSize);
            op += lastLLSize;
    }   }

    DEBUGLOG(6, "decoded block of size %u bytes", (U32)(op - ostart));
    return (size_t)(op - ostart);
}

FORCE_INLINE_TEMPLATE size_t
DONT_VECTORIZE
ZSTD_decompressSequences_body(ZSTD_DCtx* dctx,
    void* dst, size_t maxDstSize,
    const void* seqStart, size_t seqSize, int nbSeq,
    const ZSTD_longOffset_e isLongOffset)
{
    const BYTE* ip = (const BYTE*)seqStart;
    const BYTE* const iend = ip + seqSize;
    BYTE* const ostart = (BYTE*)dst;
    BYTE* const oend = dctx->litBufferLocation == ZSTD_not_in_dst ? ZSTD_maybeNullPtrAdd(ostart, maxDstSize) : dctx->litBuffer;
    BYTE* op = ostart;
    const BYTE* litPtr = dctx->litPtr;
    const BYTE* const litEnd = litPtr + dctx->litSize;
    const BYTE* const prefixStart = (const BYTE*)(dctx->prefixStart);
    const BYTE* const vBase = (const BYTE*)(dctx->virtualStart);
    const BYTE* const dictEnd = (const BYTE*)(dctx->dictEnd);
    DEBUGLOG(5, "ZSTD_decompressSequences_body: nbSeq = %d", nbSeq);

    /* Regen sequences */
    if (nbSeq) {
        seqState_t seqState;
        dctx->fseEntropy = 1;
        { U32 i; for (i = 0; i < ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
        RETURN_ERROR_IF(
            ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend - ip)),
            corruption_detected, "");
        ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
        ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
        ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);
        assert(dst != NULL);

#if defined(__GNUC__) && defined(__x86_64__)
            __asm__(".p2align 6");
            __asm__("nop");
#  if __GNUC__ >= 7
            __asm__(".p2align 5");
            __asm__("nop");
            __asm__(".p2align 3");
#  else
            __asm__(".p2align 4");
            __asm__("nop");
            __asm__(".p2align 3");
#  endif
#endif

        for ( ; nbSeq ; nbSeq--) {
            seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
            size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
            assert(!ZSTD_isError(oneSeqSize));
            ZSTD_assertValidSequence(dctx, op, oend, sequence, prefixStart, vBase);
#endif
            if (UNLIKELY(ZSTD_isError(oneSeqSize)))
                return oneSeqSize;
            DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
            op += oneSeqSize;
        }

        /* check if reached exact end */
        assert(nbSeq == 0);
        RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");
        /* save reps for next block */
        { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
    }

    /* last literal segment */
    {   size_t const lastLLSize = (size_t)(litEnd - litPtr);
        DEBUGLOG(6, "copy last literals : %u", (U32)lastLLSize);
        RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
        if (op != NULL) {
            ZSTD_memcpy(op, litPtr, lastLLSize);
            op += lastLLSize;
    }   }

    DEBUGLOG(6, "decoded block of size %u bytes", (U32)(op - ostart));
    return (size_t)(op - ostart);
}

static size_t
ZSTD_decompressSequences_default(ZSTD_DCtx* dctx,
                                 void* dst, size_t maxDstSize,
                           const void* seqStart, size_t seqSize, int nbSeq,
                           const ZSTD_longOffset_e isLongOffset)
{
    return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}

static size_t
ZSTD_decompressSequencesSplitLitBuffer_default(ZSTD_DCtx* dctx,
                                               void* dst, size_t maxDstSize,
                                         const void* seqStart, size_t seqSize, int nbSeq,
                                         const ZSTD_longOffset_e isLongOffset)
{
    return ZSTD_decompressSequences_bodySplitLitBuffer(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */

#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT

FORCE_INLINE_TEMPLATE

size_t ZSTD_prefetchMatch(size_t prefetchPos, seq_t const sequence,
                   const BYTE* const prefixStart, const BYTE* const dictEnd)
{
    prefetchPos += sequence.litLength;
    {   const BYTE* const matchBase = (sequence.offset > prefetchPos) ? dictEnd : prefixStart;
        /* note : this operation can overflow when seq.offset is really too large, which can only happen when input is corrupted.
         * No consequence though : memory address is only used for prefetching, not for dereferencing */
        const BYTE* const match = ZSTD_wrappedPtrSub(ZSTD_wrappedPtrAdd(matchBase, prefetchPos), sequence.offset);
        PREFETCH_L1(match); PREFETCH_L1(match+CACHELINE_SIZE);   /* note : it's safe to invoke PREFETCH() on any memory address, including invalid ones */
    }
    return prefetchPos + sequence.matchLength;
}

/* This decoding function employs prefetching
 * to reduce latency impact of cache misses.
 * It's generally employed when block contains a significant portion of long-distance matches
 * or when coupled with a "cold" dictionary */
FORCE_INLINE_TEMPLATE size_t
ZSTD_decompressSequencesLong_body(
                               ZSTD_DCtx* dctx,
                               void* dst, size_t maxDstSize,
                         const void* seqStart, size_t seqSize, int nbSeq,
                         const ZSTD_longOffset_e isLongOffset)
{
    const BYTE* ip = (const BYTE*)seqStart;
    const BYTE* const iend = ip + seqSize;
    BYTE* const ostart = (BYTE*)dst;
    BYTE* const oend = dctx->litBufferLocation == ZSTD_in_dst ? dctx->litBuffer : ZSTD_maybeNullPtrAdd(ostart, maxDstSize);
    BYTE* op = ostart;
    const BYTE* litPtr = dctx->litPtr;
    const BYTE* litBufferEnd = dctx->litBufferEnd;
    const BYTE* const prefixStart = (const BYTE*) (dctx->prefixStart);
    const BYTE* const dictStart = (const BYTE*) (dctx->virtualStart);
    const BYTE* const dictEnd = (const BYTE*) (dctx->dictEnd);

    /* Regen sequences */
    if (nbSeq) {
#define STORED_SEQS 8
#define STORED_SEQS_MASK (STORED_SEQS-1)
#define ADVANCED_SEQS STORED_SEQS
        seq_t sequences[STORED_SEQS];
        int const seqAdvance = MIN(nbSeq, ADVANCED_SEQS);
        seqState_t seqState;
        int seqNb;
        size_t prefetchPos = (size_t)(op-prefixStart); /* track position relative to prefixStart */

        dctx->fseEntropy = 1;
        { int i; for (i=0; i<ZSTD_REP_NUM; i++) seqState.prevOffset[i] = dctx->entropy.rep[i]; }
        assert(dst != NULL);
        assert(iend >= ip);
        RETURN_ERROR_IF(
            ERR_isError(BIT_initDStream(&seqState.DStream, ip, iend-ip)),
            corruption_detected, "");
        ZSTD_initFseState(&seqState.stateLL, &seqState.DStream, dctx->LLTptr);
        ZSTD_initFseState(&seqState.stateOffb, &seqState.DStream, dctx->OFTptr);
        ZSTD_initFseState(&seqState.stateML, &seqState.DStream, dctx->MLTptr);

        /* prepare in advance */
        for (seqNb=0; seqNb<seqAdvance; seqNb++) {
            seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, seqNb == nbSeq-1);
            prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
            sequences[seqNb] = sequence;
        }

        /* decompress without stomping litBuffer */
        for (; seqNb < nbSeq; seqNb++) {
            seq_t sequence = ZSTD_decodeSequence(&seqState, isLongOffset, seqNb == nbSeq-1);

            if (dctx->litBufferLocation == ZSTD_split && litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength > dctx->litBufferEnd) {
                /* lit buffer is reaching split point, empty out the first buffer and transition to litExtraBuffer */
                const size_t leftoverLit = dctx->litBufferEnd - litPtr;
                if (leftoverLit)
                {
                    RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
                    ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
                    sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength -= leftoverLit;
                    op += leftoverLit;
                }
                litPtr = dctx->litExtraBuffer;
                litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
                dctx->litBufferLocation = ZSTD_not_in_dst;
                {   size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                    assert(!ZSTD_isError(oneSeqSize));
                    ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart);
#endif
                    if (ZSTD_isError(oneSeqSize)) return oneSeqSize;

                    prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
                    sequences[seqNb & STORED_SEQS_MASK] = sequence;
                    op += oneSeqSize;
            }   }
            else
            {
                /* lit buffer is either wholly contained in first or second split, or not split at all*/
                size_t const oneSeqSize = dctx->litBufferLocation == ZSTD_split ?
                    ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength - WILDCOPY_OVERLENGTH, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd) :
                    ZSTD_execSequence(op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                assert(!ZSTD_isError(oneSeqSize));
                ZSTD_assertValidSequence(dctx, op, oend, sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK], prefixStart, dictStart);
#endif
                if (ZSTD_isError(oneSeqSize)) return oneSeqSize;

                prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
                sequences[seqNb & STORED_SEQS_MASK] = sequence;
                op += oneSeqSize;
            }
        }
        RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");

        /* finish queue */
        seqNb -= seqAdvance;
        for ( ; seqNb<nbSeq ; seqNb++) {
            seq_t *sequence = &(sequences[seqNb&STORED_SEQS_MASK]);
            if (dctx->litBufferLocation == ZSTD_split && litPtr + sequence->litLength > dctx->litBufferEnd) {
                const size_t leftoverLit = dctx->litBufferEnd - litPtr;
                if (leftoverLit) {
                    RETURN_ERROR_IF(leftoverLit > (size_t)(oend - op), dstSize_tooSmall, "remaining lit must fit within dstBuffer");
                    ZSTD_safecopyDstBeforeSrc(op, litPtr, leftoverLit);
                    sequence->litLength -= leftoverLit;
                    op += leftoverLit;
                }
                litPtr = dctx->litExtraBuffer;
                litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
                dctx->litBufferLocation = ZSTD_not_in_dst;
                {   size_t const oneSeqSize = ZSTD_execSequence(op, oend, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                    assert(!ZSTD_isError(oneSeqSize));
                    ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart);
#endif
                    if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
                    op += oneSeqSize;
                }
            }
            else
            {
                size_t const oneSeqSize = dctx->litBufferLocation == ZSTD_split ?
                    ZSTD_execSequenceSplitLitBuffer(op, oend, litPtr + sequence->litLength - WILDCOPY_OVERLENGTH, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd) :
                    ZSTD_execSequence(op, oend, *sequence, &litPtr, litBufferEnd, prefixStart, dictStart, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
                assert(!ZSTD_isError(oneSeqSize));
                ZSTD_assertValidSequence(dctx, op, oend, sequences[seqNb&STORED_SEQS_MASK], prefixStart, dictStart);
#endif
                if (ZSTD_isError(oneSeqSize)) return oneSeqSize;
                op += oneSeqSize;
            }
        }

        /* save reps for next block */
        { U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
    }

    /* last literal segment */
    if (dctx->litBufferLocation == ZSTD_split) { /* first deplete literal buffer in dst, then copy litExtraBuffer */
        size_t const lastLLSize = litBufferEnd - litPtr;
        RETURN_ERROR_IF(lastLLSize > (size_t)(oend - op), dstSize_tooSmall, "");
        if (op != NULL) {
            ZSTD_memmove(op, litPtr, lastLLSize);
            op += lastLLSize;
        }
        litPtr = dctx->litExtraBuffer;
        litBufferEnd = dctx->litExtraBuffer + ZSTD_LITBUFFEREXTRASIZE;
    }
    {   size_t const lastLLSize = litBufferEnd - litPtr;
        RETURN_ERROR_IF(lastLLSize > (size_t)(oend-op), dstSize_tooSmall, "");
        if (op != NULL) {
            ZSTD_memmove(op, litPtr, lastLLSize);
            op += lastLLSize;
        }
    }

    return (size_t)(op - ostart);
}

static size_t
ZSTD_decompressSequencesLong_default(ZSTD_DCtx* dctx,
                                 void* dst, size_t maxDstSize,
                           const void* seqStart, size_t seqSize, int nbSeq,
                           const ZSTD_longOffset_e isLongOffset)
{
    return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */



#if DYNAMIC_BMI2

#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
static BMI2_TARGET_ATTRIBUTE size_t
DONT_VECTORIZE
ZSTD_decompressSequences_bmi2(ZSTD_DCtx* dctx,
                                 void* dst, size_t maxDstSize,
                           const void* seqStart, size_t seqSize, int nbSeq,
                           const ZSTD_longOffset_e isLongOffset)
{
    return ZSTD_decompressSequences_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
static BMI2_TARGET_ATTRIBUTE size_t
DONT_VECTORIZE
ZSTD_decompressSequencesSplitLitBuffer_bmi2(ZSTD_DCtx* dctx,
                                 void* dst, size_t maxDstSize,
                           const void* seqStart, size_t seqSize, int nbSeq,
                           const ZSTD_longOffset_e isLongOffset)
{
    return ZSTD_decompressSequences_bodySplitLitBuffer(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */

#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
static BMI2_TARGET_ATTRIBUTE size_t
ZSTD_decompressSequencesLong_bmi2(ZSTD_DCtx* dctx,
                                 void* dst, size_t maxDstSize,
                           const void* seqStart, size_t seqSize, int nbSeq,
                           const ZSTD_longOffset_e isLongOffset)
{
    return ZSTD_decompressSequencesLong_body(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */

#endif /* DYNAMIC_BMI2 */

typedef size_t (*ZSTD_decompressSequences_t)(
                            ZSTD_DCtx* dctx,
                            void* dst, size_t maxDstSize,
                            const void* seqStart, size_t seqSize, int nbSeq,
                            const ZSTD_longOffset_e isLongOffset);

#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
static size_t
ZSTD_decompressSequences(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
                   const void* seqStart, size_t seqSize, int nbSeq,
                   const ZSTD_longOffset_e isLongOffset)
{
    DEBUGLOG(5, "ZSTD_decompressSequences");
#if DYNAMIC_BMI2
    if (ZSTD_DCtx_get_bmi2(dctx)) {
        return ZSTD_decompressSequences_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
    }
#endif
    return ZSTD_decompressSequences_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
static size_t
ZSTD_decompressSequencesSplitLitBuffer(ZSTD_DCtx* dctx, void* dst, size_t maxDstSize,
                                 const void* seqStart, size_t seqSize, int nbSeq,
                                 const ZSTD_longOffset_e isLongOffset)
{
    DEBUGLOG(5, "ZSTD_decompressSequencesSplitLitBuffer");
#if DYNAMIC_BMI2
    if (ZSTD_DCtx_get_bmi2(dctx)) {
        return ZSTD_decompressSequencesSplitLitBuffer_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
    }
#endif
    return ZSTD_decompressSequencesSplitLitBuffer_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG */


#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
/* ZSTD_decompressSequencesLong() :
 * decompression function triggered when a minimum share of offsets is considered "long",
 * aka out of cache.
 * note : "long" definition seems overloaded here, sometimes meaning "wider than bitstream register", and sometimes meaning "farther than memory cache distance".
 * This function will try to mitigate main memory latency through the use of prefetching */
static size_t
ZSTD_decompressSequencesLong(ZSTD_DCtx* dctx,
                             void* dst, size_t maxDstSize,
                             const void* seqStart, size_t seqSize, int nbSeq,
                             const ZSTD_longOffset_e isLongOffset)
{
    DEBUGLOG(5, "ZSTD_decompressSequencesLong");
#if DYNAMIC_BMI2
    if (ZSTD_DCtx_get_bmi2(dctx)) {
        return ZSTD_decompressSequencesLong_bmi2(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
    }
#endif
  return ZSTD_decompressSequencesLong_default(dctx, dst, maxDstSize, seqStart, seqSize, nbSeq, isLongOffset);
}
#endif /* ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT */


/**
 * @returns The total size of the history referenceable by zstd, including
 * both the prefix and the extDict. At @p op any offset larger than this
 * is invalid.
 */
static size_t ZSTD_totalHistorySize(BYTE* op, BYTE const* virtualStart)
{
    return (size_t)(op - virtualStart);
}

typedef struct {
    unsigned longOffsetShare;
    unsigned maxNbAdditionalBits;
} ZSTD_OffsetInfo;

/* ZSTD_getOffsetInfo() :
 * condition : offTable must be valid
 * @return : "share" of long offsets (arbitrarily defined as > (1<<23))
 *           compared to maximum possible of (1<<OffFSELog),
 *           as well as the maximum number additional bits required.
 */
static ZSTD_OffsetInfo
ZSTD_getOffsetInfo(const ZSTD_seqSymbol* offTable, int nbSeq)
{
    ZSTD_OffsetInfo info = {0, 0};
    /* If nbSeq == 0, then the offTable is uninitialized, but we have
     * no sequences, so both values should be 0.
     */
    if (nbSeq != 0) {
        const void* ptr = offTable;
        U32 const tableLog = ((const ZSTD_seqSymbol_header*)ptr)[0].tableLog;
        const ZSTD_seqSymbol* table = offTable + 1;
        U32 const max = 1 << tableLog;
        U32 u;
        DEBUGLOG(5, "ZSTD_getLongOffsetsShare: (tableLog=%u)", tableLog);

        assert(max <= (1 << OffFSELog));  /* max not too large */
        for (u=0; u<max; u++) {
            info.maxNbAdditionalBits = MAX(info.maxNbAdditionalBits, table[u].nbAdditionalBits);
            if (table[u].nbAdditionalBits > 22) info.longOffsetShare += 1;
        }

        assert(tableLog <= OffFSELog);
        info.longOffsetShare <<= (OffFSELog - tableLog);  /* scale to OffFSELog */
    }

    return info;
}

/**
 * @returns The maximum offset we can decode in one read of our bitstream, without
 * reloading more bits in the middle of the offset bits read. Any offsets larger
 * than this must use the long offset decoder.
 */
static size_t ZSTD_maxShortOffset(void)
{
    if (MEM_64bits()) {
        /* We can decode any offset without reloading bits.
         * This might change if the max window size grows.
         */
        ZSTD_STATIC_ASSERT(ZSTD_WINDOWLOG_MAX <= 31);
        return (size_t)-1;
    } else {
        /* The maximum offBase is (1 << (STREAM_ACCUMULATOR_MIN + 1)) - 1.
         * This offBase would require STREAM_ACCUMULATOR_MIN extra bits.
         * Then we have to subtract ZSTD_REP_NUM to get the maximum possible offset.
         */
        size_t const maxOffbase = ((size_t)1 << (STREAM_ACCUMULATOR_MIN + 1)) - 1;
        size_t const maxOffset = maxOffbase - ZSTD_REP_NUM;
        assert(ZSTD_highbit32((U32)maxOffbase) == STREAM_ACCUMULATOR_MIN);
        return maxOffset;
    }
}

size_t
ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
                              void* dst, size_t dstCapacity,
                        const void* src, size_t srcSize, const streaming_operation streaming)
{   /* blockType == blockCompressed */
    const BYTE* ip = (const BYTE*)src;
    DEBUGLOG(5, "ZSTD_decompressBlock_internal (cSize : %u)", (unsigned)srcSize);

    /* Note : the wording of the specification
     * allows compressed block to be sized exactly ZSTD_blockSizeMax(dctx).
     * This generally does not happen, as it makes little sense,
     * since an uncompressed block would feature same size and have no decompression cost.
     * Also, note that decoder from reference libzstd before < v1.5.4
     * would consider this edge case as an error.
     * As a consequence, avoid generating compressed blocks of size ZSTD_blockSizeMax(dctx)
     * for broader compatibility with the deployed ecosystem of zstd decoders */
    RETURN_ERROR_IF(srcSize > ZSTD_blockSizeMax(dctx), srcSize_wrong, "");

    /* Decode literals section */
    {   size_t const litCSize = ZSTD_decodeLiteralsBlock(dctx, src, srcSize, dst, dstCapacity, streaming);
        DEBUGLOG(5, "ZSTD_decodeLiteralsBlock : cSize=%u, nbLiterals=%zu", (U32)litCSize, dctx->litSize);
        if (ZSTD_isError(litCSize)) return litCSize;
        ip += litCSize;
        srcSize -= litCSize;
    }

    /* Build Decoding Tables */
    {
        /* Compute the maximum block size, which must also work when !frame and fParams are unset.
         * Additionally, take the min with dstCapacity to ensure that the totalHistorySize fits in a size_t.
         */
        size_t const blockSizeMax = MIN(dstCapacity, ZSTD_blockSizeMax(dctx));
        size_t const totalHistorySize = ZSTD_totalHistorySize(ZSTD_maybeNullPtrAdd((BYTE*)dst, blockSizeMax), (BYTE const*)dctx->virtualStart);
        /* isLongOffset must be true if there are long offsets.
         * Offsets are long if they are larger than ZSTD_maxShortOffset().
         * We don't expect that to be the case in 64-bit mode.
         *
         * We check here to see if our history is large enough to allow long offsets.
         * If it isn't, then we can't possible have (valid) long offsets. If the offset
         * is invalid, then it is okay to read it incorrectly.
         *
         * If isLongOffsets is true, then we will later check our decoding table to see
         * if it is even possible to generate long offsets.
         */
        ZSTD_longOffset_e isLongOffset = (ZSTD_longOffset_e)(MEM_32bits() && (totalHistorySize > ZSTD_maxShortOffset()));
        /* These macros control at build-time which decompressor implementation
         * we use. If neither is defined, we do some inspection and dispatch at
         * runtime.
         */
#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
    !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
        int usePrefetchDecoder = dctx->ddictIsCold;
#else
        /* Set to 1 to avoid computing offset info if we don't need to.
         * Otherwise this value is ignored.
         */
        int usePrefetchDecoder = 1;
#endif
        int nbSeq;
        size_t const seqHSize = ZSTD_decodeSeqHeaders(dctx, &nbSeq, ip, srcSize);
        if (ZSTD_isError(seqHSize)) return seqHSize;
        ip += seqHSize;
        srcSize -= seqHSize;

        RETURN_ERROR_IF((dst == NULL || dstCapacity == 0) && nbSeq > 0, dstSize_tooSmall, "NULL not handled");
        RETURN_ERROR_IF(MEM_64bits() && sizeof(size_t) == sizeof(void*) && (size_t)(-1) - (size_t)dst < (size_t)(1 << 20), dstSize_tooSmall,
                "invalid dst");

        /* If we could potentially have long offsets, or we might want to use the prefetch decoder,
         * compute information about the share of long offsets, and the maximum nbAdditionalBits.
         * NOTE: could probably use a larger nbSeq limit
         */
        if (isLongOffset || (!usePrefetchDecoder && (totalHistorySize > (1u << 24)) && (nbSeq > 8))) {
            ZSTD_OffsetInfo const info = ZSTD_getOffsetInfo(dctx->OFTptr, nbSeq);
            if (isLongOffset && info.maxNbAdditionalBits <= STREAM_ACCUMULATOR_MIN) {
                /* If isLongOffset, but the maximum number of additional bits that we see in our table is small
                 * enough, then we know it is impossible to have too long an offset in this block, so we can
                 * use the regular offset decoder.
                 */
                isLongOffset = ZSTD_lo_isRegularOffset;
            }
            if (!usePrefetchDecoder) {
                U32 const minShare = MEM_64bits() ? 7 : 20; /* heuristic values, correspond to 2.73% and 7.81% */
                usePrefetchDecoder = (info.longOffsetShare >= minShare);
            }
        }

        dctx->ddictIsCold = 0;

#if !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT) && \
    !defined(ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG)
        if (usePrefetchDecoder) {
#else
        (void)usePrefetchDecoder;
        {
#endif
#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_SHORT
            return ZSTD_decompressSequencesLong(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
#endif
        }

#ifndef ZSTD_FORCE_DECOMPRESS_SEQUENCES_LONG
        /* else */
        if (dctx->litBufferLocation == ZSTD_split)
            return ZSTD_decompressSequencesSplitLitBuffer(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
        else
            return ZSTD_decompressSequences(dctx, dst, dstCapacity, ip, srcSize, nbSeq, isLongOffset);
#endif
    }
}


ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
void ZSTD_checkContinuity(ZSTD_DCtx* dctx, const void* dst, size_t dstSize)
{
    if (dst != dctx->previousDstEnd && dstSize > 0) {   /* not contiguous */
        dctx->dictEnd = dctx->previousDstEnd;
        dctx->virtualStart = (const char*)dst - ((const char*)(dctx->previousDstEnd) - (const char*)(dctx->prefixStart));
        dctx->prefixStart = dst;
        dctx->previousDstEnd = dst;
    }
}


size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx,
                                       void* dst, size_t dstCapacity,
                                 const void* src, size_t srcSize)
{
    size_t dSize;
    dctx->isFrameDecompression = 0;
    ZSTD_checkContinuity(dctx, dst, dstCapacity);
    dSize = ZSTD_decompressBlock_internal(dctx, dst, dstCapacity, src, srcSize, not_streaming);
    FORWARD_IF_ERROR(dSize, "");
    dctx->previousDstEnd = (char*)dst + dSize;
    return dSize;
}


/* NOTE: Must just wrap ZSTD_decompressBlock_deprecated() */
size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx,
                            void* dst, size_t dstCapacity,
                      const void* src, size_t srcSize)
{
    return ZSTD_decompressBlock_deprecated(dctx, dst, dstCapacity, src, srcSize);
}
/**** ended inlining decompress/zstd_decompress_block.c ****/