diff options
Diffstat (limited to 'src/liblzma/lz/lz_encoder_hash.h')
| -rw-r--r-- | src/liblzma/lz/lz_encoder_hash.h | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/src/liblzma/lz/lz_encoder_hash.h b/src/liblzma/lz/lz_encoder_hash.h new file mode 100644 index 0000000..4d9971a --- /dev/null +++ b/src/liblzma/lz/lz_encoder_hash.h @@ -0,0 +1,109 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file lz_encoder_hash.h +/// \brief Hash macros for match finders +// +// Author: Igor Pavlov +// +// This file has been put into the public domain. +// You can do whatever you want with this file. +// +/////////////////////////////////////////////////////////////////////////////// + +#ifndef LZMA_LZ_ENCODER_HASH_H +#define LZMA_LZ_ENCODER_HASH_H + +#if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL) + // This is to make liblzma produce the same output on big endian + // systems that it does on little endian systems. lz_encoder.c + // takes care of including the actual table. + lzma_attr_visibility_hidden + extern const uint32_t lzma_lz_hash_table[256]; +# define hash_table lzma_lz_hash_table +#else +# include "check.h" +# define hash_table lzma_crc32_table[0] +#endif + +#define HASH_2_SIZE (UINT32_C(1) << 10) +#define HASH_3_SIZE (UINT32_C(1) << 16) +#define HASH_4_SIZE (UINT32_C(1) << 20) + +#define HASH_2_MASK (HASH_2_SIZE - 1) +#define HASH_3_MASK (HASH_3_SIZE - 1) +#define HASH_4_MASK (HASH_4_SIZE - 1) + +#define FIX_3_HASH_SIZE (HASH_2_SIZE) +#define FIX_4_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE) +#define FIX_5_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE + HASH_4_SIZE) + +// Endianness doesn't matter in hash_2_calc() (no effect on the output). +#ifdef TUKLIB_FAST_UNALIGNED_ACCESS +# define hash_2_calc() \ + const uint32_t hash_value = read16ne(cur) +#else +# define hash_2_calc() \ + const uint32_t hash_value \ + = (uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8) +#endif + +#define hash_3_calc() \ + const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ + const uint32_t hash_2_value = temp & HASH_2_MASK; \ + const uint32_t hash_value \ + = (temp ^ ((uint32_t)(cur[2]) << 8)) & mf->hash_mask + +#define hash_4_calc() \ + const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ + const uint32_t hash_2_value = temp & HASH_2_MASK; \ + const uint32_t hash_3_value \ + = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ + const uint32_t hash_value = (temp ^ ((uint32_t)(cur[2]) << 8) \ + ^ (hash_table[cur[3]] << 5)) & mf->hash_mask + + +// The following are not currently used. + +#define hash_5_calc() \ + const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ + const uint32_t hash_2_value = temp & HASH_2_MASK; \ + const uint32_t hash_3_value \ + = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ + uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \ + ^ hash_table[cur[3]] << 5); \ + const uint32_t hash_value \ + = (hash_4_value ^ (hash_table[cur[4]] << 3)) \ + & mf->hash_mask; \ + hash_4_value &= HASH_4_MASK + +/* +#define hash_zip_calc() \ + const uint32_t hash_value \ + = (((uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)) \ + ^ hash_table[cur[2]]) & 0xFFFF +*/ + +#define hash_zip_calc() \ + const uint32_t hash_value \ + = (((uint32_t)(cur[2]) | ((uint32_t)(cur[0]) << 8)) \ + ^ hash_table[cur[1]]) & 0xFFFF + +#define mt_hash_2_calc() \ + const uint32_t hash_2_value \ + = (hash_table[cur[0]] ^ cur[1]) & HASH_2_MASK + +#define mt_hash_3_calc() \ + const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ + const uint32_t hash_2_value = temp & HASH_2_MASK; \ + const uint32_t hash_3_value \ + = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK + +#define mt_hash_4_calc() \ + const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ + const uint32_t hash_2_value = temp & HASH_2_MASK; \ + const uint32_t hash_3_value \ + = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ + const uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \ + (hash_table[cur[3]] << 5)) & HASH_4_MASK + +#endif |