| /////////////////////////////////////////////////////////////////////////////// |
| // |
| /// \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 |
| |
| #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) |
| |
| // TODO Benchmark, and probably doesn't need to be endian dependent. |
| #if !defined(WORDS_BIGENDIAN) && defined(HAVE_FAST_UNALIGNED_ACCESS) |
| # define hash_2_calc() \ |
| const uint32_t hash_value = *(const uint16_t *)(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 = lzma_crc32_table[0][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 = lzma_crc32_table[0][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) \ |
| ^ (lzma_crc32_table[0][cur[3]] << 5)) & mf->hash_mask |
| |
| |
| // The following are not currently used. |
| |
| #define hash_5_calc() \ |
| const uint32_t temp = lzma_crc32_table[0][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) ^ \ |
| ^ lzma_crc32_table[0][cur[3]] << 5); \ |
| const uint32_t hash_value \ |
| = (hash_4_value ^ (lzma_crc32_table[0][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)) \ |
| ^ lzma_crc32_table[0][cur[2]]) & 0xFFFF |
| */ |
| |
| #define hash_zip_calc() \ |
| const uint32_t hash_value \ |
| = (((uint32_t)(cur[2]) | ((uint32_t)(cur[0]) << 8)) \ |
| ^ lzma_crc32_table[0][cur[1]]) & 0xFFFF |
| |
| #define mt_hash_2_calc() \ |
| const uint32_t hash_2_value \ |
| = (lzma_crc32_table[0][cur[0]] ^ cur[1]) & HASH_2_MASK |
| |
| #define mt_hash_3_calc() \ |
| const uint32_t temp = lzma_crc32_table[0][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 = lzma_crc32_table[0][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) ^ \ |
| (lzma_crc32_table[0][cur[3]] << 5)) & HASH_4_MASK |
| |
| #endif |