clang/lib/Headers/lzcntintrin.h

   1 /*===---- lzcntintrin.h - LZCNT intrinsics ---------------------------------===
   2  *
   3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4  * See https://llvm.org/LICENSE.txt for license information.
   5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6  *
   7  *===-----------------------------------------------------------------------===
   8  */
   9
  10 #if !defined __X86INTRIN_H && !defined __IMMINTRIN_H
  11 #error "Never use <lzcntintrin.h> directly; include <x86intrin.h> instead."
  12 #endif
  13
  14 #ifndef __LZCNTINTRIN_H
  15 #define __LZCNTINTRIN_H
  16
  17 /* Define the default attributes for the functions in this file. */
  18 #if defined(__cplusplus) && (__cplusplus >= 201103L)
  19 #define __DEFAULT_FN_ATTRS                                                     \
  20   __attribute__((__always_inline__, __nodebug__, __target__("lzcnt"))) constexpr
  21 #else
  22 #define __DEFAULT_FN_ATTRS                                                     \
  23   __attribute__((__always_inline__, __nodebug__, __target__("lzcnt")))
  24 #endif
  25
  26 #ifndef _MSC_VER
  27 /// Counts the number of leading zero bits in the operand.
  28 ///
  29 /// \headerfile <x86intrin.h>
  30 ///
  31 /// This intrinsic corresponds to the \c LZCNT instruction.
  32 ///
  33 /// \param __X
  34 ///    An unsigned 16-bit integer whose leading zeros are to be counted.
  35 /// \returns An unsigned 16-bit integer containing the number of leading zero
  36 ///    bits in the operand.
  37 #define __lzcnt16(X) __builtin_ia32_lzcnt_u16((unsigned short)(X))
  38 #endif // _MSC_VER
  39
  40 /// Counts the number of leading zero bits in the operand.
  41 ///
  42 /// \headerfile <x86intrin.h>
  43 ///
  44 /// This intrinsic corresponds to the \c LZCNT instruction.
  45 ///
  46 /// \param __X
  47 ///    An unsigned 32-bit integer whose leading zeros are to be counted.
  48 /// \returns An unsigned 32-bit integer containing the number of leading zero
  49 ///    bits in the operand.
  50 /// \see _lzcnt_u32
  51 static __inline__ unsigned int __DEFAULT_FN_ATTRS
  52 __lzcnt32(unsigned int __X) {
  53   return __builtin_ia32_lzcnt_u32(__X);
  54 }
  55
  56 /// Counts the number of leading zero bits in the operand.
  57 ///
  58 /// \headerfile <x86intrin.h>
  59 ///
  60 /// This intrinsic corresponds to the \c LZCNT instruction.
  61 ///
  62 /// \param __X
  63 ///    An unsigned 32-bit integer whose leading zeros are to be counted.
  64 /// \returns An unsigned 32-bit integer containing the number of leading zero
  65 ///    bits in the operand.
  66 /// \see __lzcnt32
  67 static __inline__ unsigned int __DEFAULT_FN_ATTRS
  68 _lzcnt_u32(unsigned int __X) {
  69   return __builtin_ia32_lzcnt_u32(__X);
  70 }
  71
  72 #ifdef __x86_64__
  73 #ifndef _MSC_VER
  74 /// Counts the number of leading zero bits in the operand.
  75 ///
  76 /// \headerfile <x86intrin.h>
  77 ///
  78 /// This intrinsic corresponds to the \c LZCNT instruction.
  79 ///
  80 /// \param __X
  81 ///    An unsigned 64-bit integer whose leading zeros are to be counted.
  82 /// \returns An unsigned 64-bit integer containing the number of leading zero
  83 ///    bits in the operand.
  84 /// \see _lzcnt_u64
  85 #define __lzcnt64(X) __builtin_ia32_lzcnt_u64((unsigned long long)(X))
  86 #endif // _MSC_VER
  87
  88 /// Counts the number of leading zero bits in the operand.
  89 ///
  90 /// \headerfile <x86intrin.h>
  91 ///
  92 /// This intrinsic corresponds to the \c LZCNT instruction.
  93 ///
  94 /// \param __X
  95 ///    An unsigned 64-bit integer whose leading zeros are to be counted.
  96 /// \returns An unsigned 64-bit integer containing the number of leading zero
  97 ///    bits in the operand.
  98 /// \see __lzcnt64
  99 static __inline__ unsigned long long __DEFAULT_FN_ATTRS
 100 _lzcnt_u64(unsigned long long __X) {
 101   return __builtin_ia32_lzcnt_u64(__X);
 102 }
 103 #endif
 104
 105 #undef __DEFAULT_FN_ATTRS
 106
 107 #endif /* __LZCNTINTRIN_H */