CoCalc -- lz_encoder

GitHub Repository: Kitware/CMake
Path: blob/master/Utilities/cmliblzma/liblzma/lz/lz_encoder_hash.h
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// SPDX-License-Identifier: 0BSD
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///////////////////////////////////////////////////////////////////////////////
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//
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/// \file       lz_encoder_hash.h
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/// \brief      Hash macros for match finders
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//
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//  Author:     Igor Pavlov
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//
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///////////////////////////////////////////////////////////////////////////////
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#ifndef LZMA_LZ_ENCODER_HASH_H
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#define LZMA_LZ_ENCODER_HASH_H
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#if defined(WORDS_BIGENDIAN) && !defined(HAVE_SMALL)
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	// This is to make liblzma produce the same output on big endian
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	// systems that it does on little endian systems. lz_encoder.c
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	// takes care of including the actual table.
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	lzma_attr_visibility_hidden
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	extern const uint32_t lzma_lz_hash_table[256];
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#	define hash_table lzma_lz_hash_table
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#else
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#	include "check.h"
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#	define hash_table lzma_crc32_table[0]
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#endif
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#define HASH_2_SIZE (UINT32_C(1) << 10)
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#define HASH_3_SIZE (UINT32_C(1) << 16)
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#define HASH_4_SIZE (UINT32_C(1) << 20)
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#define HASH_2_MASK (HASH_2_SIZE - 1)
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#define HASH_3_MASK (HASH_3_SIZE - 1)
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#define HASH_4_MASK (HASH_4_SIZE - 1)
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#define FIX_3_HASH_SIZE (HASH_2_SIZE)
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#define FIX_4_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE)
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#define FIX_5_HASH_SIZE (HASH_2_SIZE + HASH_3_SIZE + HASH_4_SIZE)
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// Endianness doesn't matter in hash_2_calc() (no effect on the output).
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#ifdef TUKLIB_FAST_UNALIGNED_ACCESS
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#	define hash_2_calc() \
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		const uint32_t hash_value = read16ne(cur)
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#else
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#	define hash_2_calc() \
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		const uint32_t hash_value \
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			= (uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)
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#endif
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#define hash_3_calc() \
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	const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
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	const uint32_t hash_2_value = temp & HASH_2_MASK; \
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	const uint32_t hash_value \
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			= (temp ^ ((uint32_t)(cur[2]) << 8)) & mf->hash_mask
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#define hash_4_calc() \
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	const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
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	const uint32_t hash_2_value = temp & HASH_2_MASK; \
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	const uint32_t hash_3_value \
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			= (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \
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	const uint32_t hash_value = (temp ^ ((uint32_t)(cur[2]) << 8) \
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			^ (hash_table[cur[3]] << 5)) & mf->hash_mask
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// The following are not currently used.
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#define hash_5_calc() \
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	const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
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	const uint32_t hash_2_value = temp & HASH_2_MASK; \
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	const uint32_t hash_3_value \
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			= (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \
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	uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \
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			^ hash_table[cur[3]] << 5); \
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	const uint32_t hash_value \
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			= (hash_4_value ^ (hash_table[cur[4]] << 3)) \
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				& mf->hash_mask; \
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	hash_4_value &= HASH_4_MASK
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/*
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#define hash_zip_calc() \
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	const uint32_t hash_value \
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			= (((uint32_t)(cur[0]) | ((uint32_t)(cur[1]) << 8)) \
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				^ hash_table[cur[2]]) & 0xFFFF
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*/
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#define hash_zip_calc() \
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	const uint32_t hash_value \
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			= (((uint32_t)(cur[2]) | ((uint32_t)(cur[0]) << 8)) \
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				^ hash_table[cur[1]]) & 0xFFFF
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#define mt_hash_2_calc() \
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	const uint32_t hash_2_value \
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			= (hash_table[cur[0]] ^ cur[1]) & HASH_2_MASK
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#define mt_hash_3_calc() \
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	const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
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	const uint32_t hash_2_value = temp & HASH_2_MASK; \
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	const uint32_t hash_3_value \
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			= (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK
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#define mt_hash_4_calc() \
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	const uint32_t temp = hash_table[cur[0]] ^ cur[1]; \
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	const uint32_t hash_2_value = temp & HASH_2_MASK; \
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	const uint32_t hash_3_value \
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			= (temp ^ ((uint32_t)(cur[2]) << 8)) & HASH_3_MASK; \
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	const uint32_t hash_4_value = (temp ^ ((uint32_t)(cur[2]) << 8) ^ \
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			(hash_table[cur[3]] << 5)) & HASH_4_MASK
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#endif
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