1 /////////////////////////////////////////////////////////////////////////////// 2 // 3 /// \file lz_encoder_hash.h 4 /// \brief Hash macros for match finders 5 // 6 // Author: Igor Pavlov 7 // 8 // This file has been put into the public domain. 9 // You can do whatever you want with this file. 10 // 11 /////////////////////////////////////////////////////////////////////////////// 12 13 #ifndef LZMA_LZ_ENCODER_HASH_H 14 #define LZMA_LZ_ENCODER_HASH_H 15 16 #if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL) 17 // This is to make liblzma produce the same output on big endian 18 // systems that it does on little endian systems. lz_encoder.c 19 // takes care of including the actual table. 20 extern const uint32_t lzma_lz_hash_table[256]; 21 # define hash_table lzma_lz_hash_table 22 #else 23 # include "check.h" 24 # define hash_table lzma_crc32_table[0] 25 #endif 26 27 #define HASH_2_SIZE (UINT32_C(1) << 10) 28 #define HASH_3_SIZE (UINT32_C(1) << 16) 29 #define HASH_4_SIZE (UINT32_C(1) << 20) 30 31 #define HASH_2_MASK (HASH_2_SIZE - 1) 32 #define HASH_3_MASK (HASH_3_SIZE - 1) 33 #define HASH_4_MASK (HASH_4_SIZE - 1) 34 35 #define FIX_3_HASH_SIZE (HASH_2_SIZE) 36 #define FIX_4_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE) 37 #define FIX_5_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE + HASH_4_SIZE) 38 39 // Endianness doesn't matter in hash_2_calc() (no effect on the output). 40 #ifdef TUKLIB_FAST_UNALIGNED_ACCESS 41 # define hash_2_calc() \ 42 const uint32_t hash_value = read16ne(cur) 43 #else 44 # define hash_2_calc() \ 45 const uint32_t hash_value \ 46 = (uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8) 47 #endif 48 49 #define hash_3_calc() \ 50 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 51 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 52 const uint32_t hash_value \ 53 = (temp ^ ((uint32_t)(cur[2]) << 8)) & mf->hash_mask 54 55 #define hash_4_calc() \ 56 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 57 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 58 const uint32_t hash_3_value \ 59 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ 60 const uint32_t hash_value = (temp ^ ((uint32_t)(cur[2]) << 8) \ 61 ^ (hash_table[cur[3]] << 5)) & mf->hash_mask 62 63 64 // The following are not currently used. 65 66 #define hash_5_calc() \ 67 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 68 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 69 const uint32_t hash_3_value \ 70 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ 71 uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \ 72 ^ hash_table[cur[3]] << 5); \ 73 const uint32_t hash_value \ 74 = (hash_4_value ^ (hash_table[cur[4]] << 3)) \ 75 & mf->hash_mask; \ 76 hash_4_value &= HASH_4_MASK 77 78 /* 79 #define hash_zip_calc() \ 80 const uint32_t hash_value \ 81 = (((uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)) \ 82 ^ hash_table[cur[2]]) & 0xFFFF 83 */ 84 85 #define hash_zip_calc() \ 86 const uint32_t hash_value \ 87 = (((uint32_t)(cur[2]) | ((uint32_t)(cur[0]) << 8)) \ 88 ^ hash_table[cur[1]]) & 0xFFFF 89 90 #define mt_hash_2_calc() \ 91 const uint32_t hash_2_value \ 92 = (hash_table[cur[0]] ^ cur[1]) & HASH_2_MASK 93 94 #define mt_hash_3_calc() \ 95 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 96 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 97 const uint32_t hash_3_value \ 98 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK 99 100 #define mt_hash_4_calc() \ 101 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 102 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 103 const uint32_t hash_3_value \ 104 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ 105 const uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \ 106 (hash_table[cur[3]] << 5)) & HASH_4_MASK 107 108 #endif 109