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-rw-r--r--src/liblzma/lz/lz_encoder_hash.h104
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
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+++ b/src/liblzma/lz/lz_encoder_hash.h
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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