diff options
Diffstat (limited to 'src/liblzma/lz/lz_encoder_hash.h')
-rw-r--r-- | src/liblzma/lz/lz_encoder_hash.h | 104 |
1 files changed, 104 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 00000000..0841c38f --- /dev/null +++ b/src/liblzma/lz/lz_encoder_hash.h @@ -0,0 +1,104 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file lz_encoder_hash.h +/// \brief Hash macros for match finders +// +// Copyright (C) 1999-2008 Igor Pavlov +// +// This library is free software; you can redistribute it and/or +// modify it under the terms of the GNU Lesser General Public +// License as published by the Free Software Foundation; either +// version 2.1 of the License, or (at your option) any later version. +// +// This library is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +// Lesser General Public License for more details. +// +/////////////////////////////////////////////////////////////////////////////// + +#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 |