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 lzma_attr_visibility_hidden 21 extern const uint32_t lzma_lz_hash_table[256]; 22 # define hash_table lzma_lz_hash_table 23 #else 24 # include "check.h" 25 # define hash_table lzma_crc32_table[0] 26 #endif 27 28 #define HASH_2_SIZE (UINT32_C(1) << 10) 29 #define HASH_3_SIZE (UINT32_C(1) << 16) 30 #define HASH_4_SIZE (UINT32_C(1) << 20) 31 32 #define HASH_2_MASK (HASH_2_SIZE - 1) 33 #define HASH_3_MASK (HASH_3_SIZE - 1) 34 #define HASH_4_MASK (HASH_4_SIZE - 1) 35 36 #define FIX_3_HASH_SIZE (HASH_2_SIZE) 37 #define FIX_4_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE) 38 #define FIX_5_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE + HASH_4_SIZE) 39 40 // Endianness doesn't matter in hash_2_calc() (no effect on the output). 41 #ifdef TUKLIB_FAST_UNALIGNED_ACCESS 42 # define hash_2_calc() \ 43 const uint32_t hash_value = read16ne(cur) 44 #else 45 # define hash_2_calc() \ 46 const uint32_t hash_value \ 47 = (uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8) 48 #endif 49 50 #define hash_3_calc() \ 51 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 52 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 53 const uint32_t hash_value \ 54 = (temp ^ ((uint32_t)(cur[2]) << 8)) & mf->hash_mask 55 56 #define hash_4_calc() \ 57 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 58 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 59 const uint32_t hash_3_value \ 60 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ 61 const uint32_t hash_value = (temp ^ ((uint32_t)(cur[2]) << 8) \ 62 ^ (hash_table[cur[3]] << 5)) & mf->hash_mask 63 64 65 // The following are not currently used. 66 67 #define hash_5_calc() \ 68 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 69 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 70 const uint32_t hash_3_value \ 71 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ 72 uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \ 73 ^ hash_table[cur[3]] << 5); \ 74 const uint32_t hash_value \ 75 = (hash_4_value ^ (hash_table[cur[4]] << 3)) \ 76 & mf->hash_mask; \ 77 hash_4_value &= HASH_4_MASK 78 79 /* 80 #define hash_zip_calc() \ 81 const uint32_t hash_value \ 82 = (((uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)) \ 83 ^ hash_table[cur[2]]) & 0xFFFF 84 */ 85 86 #define hash_zip_calc() \ 87 const uint32_t hash_value \ 88 = (((uint32_t)(cur[2]) | ((uint32_t)(cur[0]) << 8)) \ 89 ^ hash_table[cur[1]]) & 0xFFFF 90 91 #define mt_hash_2_calc() \ 92 const uint32_t hash_2_value \ 93 = (hash_table[cur[0]] ^ cur[1]) & HASH_2_MASK 94 95 #define mt_hash_3_calc() \ 96 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 97 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 98 const uint32_t hash_3_value \ 99 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK 100 101 #define mt_hash_4_calc() \ 102 const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \ 103 const uint32_t hash_2_value = temp & HASH_2_MASK; \ 104 const uint32_t hash_3_value \ 105 = (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \ 106 const uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \ 107 (hash_table[cur[3]] << 5)) & HASH_4_MASK 108 109 #endif 110