lib/lz4/lz4defs.h

   1 /*
   2  * lz4defs.h -- architecture specific defines
   3  *
   4  * Copyright (C) 2013, LG Electronics, Kyungsik Lee <kyungsik.lee@lge.com>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 /*
  12  * Detects 64 bits mode
  13  */
  14 #if defined(CONFIG_64BIT)
  15 #define LZ4_ARCH64 1
  16 #else
  17 #define LZ4_ARCH64 0
  18 #endif
  19
  20 /*
  21  * Architecture-specific macros
  22  */
  23 #define BYTE    u8
  24 typedef struct _U16_S { u16 v; } U16_S;
  25 typedef struct _U32_S { u32 v; } U32_S;
  26 typedef struct _U64_S { u64 v; } U64_S;
  27 #if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)             \
  28         || defined(CONFIG_ARM) && __LINUX_ARM_ARCH__ >= 6       \
  29         && defined(ARM_EFFICIENT_UNALIGNED_ACCESS)
  30
  31 #define A16(x) (((U16_S *)(x))->v)
  32 #define A32(x) (((U32_S *)(x))->v)
  33 #define A64(x) (((U64_S *)(x))->v)
  34
  35 #define PUT4(s, d) (A32(d) = A32(s))
  36 #define PUT8(s, d) (A64(d) = A64(s))
  37
  38 #define LZ4_READ_LITTLEENDIAN_16(d, s, p)       \
  39         (d = s - A16(p))
  40
  41 #define LZ4_WRITE_LITTLEENDIAN_16(p, v) \
  42         do {    \
  43                 A16(p) = v; \
  44                 p += 2; \
  45         } while (0)
  46 #else /* CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS */
  47
  48 #define A64(x) get_unaligned((u64 *)&(((U16_S *)(x))->v))
  49 #define A32(x) get_unaligned((u32 *)&(((U16_S *)(x))->v))
  50 #define A16(x) get_unaligned((u16 *)&(((U16_S *)(x))->v))
  51
  52 #define PUT4(s, d) \
  53         put_unaligned(get_unaligned((const u32 *) s), (u32 *) d)
  54 #define PUT8(s, d) \
  55         put_unaligned(get_unaligned((const u64 *) s), (u64 *) d)
  56
  57 #define LZ4_READ_LITTLEENDIAN_16(d, s, p)       \
  58         (d = s - get_unaligned_le16(p))
  59
  60 #define LZ4_WRITE_LITTLEENDIAN_16(p, v)                 \
  61         do {                                            \
  62                 put_unaligned_le16(v, (u16 *)(p));      \
  63                 p += 2;                                 \
  64         } while (0)
  65 #endif
  66
  67 #define COPYLENGTH 8
  68 #define ML_BITS  4
  69 #define ML_MASK  ((1U << ML_BITS) - 1)
  70 #define RUN_BITS (8 - ML_BITS)
  71 #define RUN_MASK ((1U << RUN_BITS) - 1)
  72 #define MEMORY_USAGE    14
  73 #define MINMATCH        4
  74 #define SKIPSTRENGTH    6
  75 #define LASTLITERALS    5
  76 #define MFLIMIT         (COPYLENGTH + MINMATCH)
  77 #define MINLENGTH       (MFLIMIT + 1)
  78 #define MAXD_LOG        16
  79 #define MAXD            (1 << MAXD_LOG)
  80 #define MAXD_MASK       (u32)(MAXD - 1)
  81 #define MAX_DISTANCE    (MAXD - 1)
  82 #define HASH_LOG        (MAXD_LOG - 1)
  83 #define HASHTABLESIZE   (1 << HASH_LOG)
  84 #define MAX_NB_ATTEMPTS 256
  85 #define OPTIMAL_ML      (int)((ML_MASK-1)+MINMATCH)
  86 #define LZ4_64KLIMIT    ((1<<16) + (MFLIMIT - 1))
  87 #define HASHLOG64K      ((MEMORY_USAGE - 2) + 1)
  88 #define HASH64KTABLESIZE        (1U << HASHLOG64K)
  89 #define LZ4_HASH_VALUE(p)       (((A32(p)) * 2654435761U) >> \
  90                                 ((MINMATCH * 8) - (MEMORY_USAGE-2)))
  91 #define LZ4_HASH64K_VALUE(p)    (((A32(p)) * 2654435761U) >> \
  92                                 ((MINMATCH * 8) - HASHLOG64K))
  93 #define HASH_VALUE(p)           (((A32(p)) * 2654435761U) >> \
  94                                 ((MINMATCH * 8) - HASH_LOG))
  95
  96 #if LZ4_ARCH64/* 64-bit */
  97 #define STEPSIZE 8
  98
  99 #define LZ4_COPYSTEP(s, d)      \
 100         do {                    \
 101                 PUT8(s, d);     \
 102                 d += 8;         \
 103                 s += 8;         \
 104         } while (0)
 105
 106 #define LZ4_COPYPACKET(s, d)    LZ4_COPYSTEP(s, d)
 107
 108 #define LZ4_SECURECOPY(s, d, e)                 \
 109         do {                                    \
 110                 if (d < e) {                    \
 111                         LZ4_WILDCOPY(s, d, e);  \
 112                 }                               \
 113         } while (0)
 114 #define HTYPE u32
 115
 116 #ifdef __BIG_ENDIAN
 117 #define LZ4_NBCOMMONBYTES(val) (__builtin_clzll(val) >> 3)
 118 #else
 119 #define LZ4_NBCOMMONBYTES(val) (__builtin_ctzll(val) >> 3)
 120 #endif
 121
 122 #else   /* 32-bit */
 123 #define STEPSIZE 4
 124
 125 #define LZ4_COPYSTEP(s, d)      \
 126         do {                    \
 127                 PUT4(s, d);     \
 128                 d += 4;         \
 129                 s += 4;         \
 130         } while (0)
 131
 132 #define LZ4_COPYPACKET(s, d)            \
 133         do {                            \
 134                 LZ4_COPYSTEP(s, d);     \
 135                 LZ4_COPYSTEP(s, d);     \
 136         } while (0)
 137
 138 #define LZ4_SECURECOPY  LZ4_WILDCOPY
 139 #define HTYPE const u8*
 140
 141 #ifdef __BIG_ENDIAN
 142 #define LZ4_NBCOMMONBYTES(val) (__builtin_clz(val) >> 3)
 143 #else
 144 #define LZ4_NBCOMMONBYTES(val) (__builtin_ctz(val) >> 3)
 145 #endif
 146
 147 #endif
 148
 149 #define LZ4_WILDCOPY(s, d, e)           \
 150         do {                            \
 151                 LZ4_COPYPACKET(s, d);   \
 152         } while (d < e)
 153
 154 #define LZ4_BLINDCOPY(s, d, l)  \
 155         do {    \
 156                 u8 *e = (d) + l;        \
 157                 LZ4_WILDCOPY(s, d, e);  \
 158                 d = e;  \
 159         } while (0)