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7ed9d943b3
Half of developers were already forgetting to use these functions, which could have caused total breakage in some future liblzma version or even now if --enable-small was used. Now liblzma uses pthread_once() to do the initializations unless it has been built with --disable-threads which make these initializations thread-unsafe. When --enable-small isn't used, liblzma currently gets needlessly linked against libpthread (on systems that have it). While it is stupid for now, liblzma will need threads in future anyway, so this stupidity will be temporary only. When --enable-small is used, different code CRC32 and CRC64 is now used than without --enable-small. This made the resulting binary slightly smaller, but the main reason was to clean it up and to handle the lack of lzma_init_check(). The pkg-config file lzma.pc was renamed to liblzma.pc. I'm not sure if it works correctly and portably for static linking (Libs.private includes -pthread or other operating system specific flags). Hopefully someone complains if it is bad. lzma_rc_prices[] is now included as a precomputed array even with --enable-small. It's just 128 bytes now that it uses uint8_t instead of uint32_t. Smaller array seemed to be at least as fast as the more bloated uint32_t array on x86; hopefully it's not bad on other architectures.
99 lines
2.4 KiB
C
99 lines
2.4 KiB
C
///////////////////////////////////////////////////////////////////////////////
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//
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/// \file price.h
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/// \brief Probability price calculation
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//
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// Copyright (C) 1999-2008 Igor Pavlov
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//
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// This library is free software; you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public
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// License as published by the Free Software Foundation; either
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// version 2.1 of the License, or (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Lesser General Public License for more details.
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//
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///////////////////////////////////////////////////////////////////////////////
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#ifndef LZMA_PRICE_H
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#define LZMA_PRICE_H
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#define RC_MOVE_REDUCING_BITS 4
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#define RC_BIT_PRICE_SHIFT_BITS 4
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#define RC_PRICE_TABLE_SIZE (RC_BIT_MODEL_TOTAL >> RC_MOVE_REDUCING_BITS)
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#define RC_INFINITY_PRICE (UINT32_C(1) << 30)
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/// Lookup table for the inline functions defined in this file.
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extern const uint8_t lzma_rc_prices[RC_PRICE_TABLE_SIZE];
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static inline uint32_t
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rc_bit_price(const probability prob, const uint32_t bit)
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{
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return lzma_rc_prices[(prob ^ ((UINT32_C(0) - bit)
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& (RC_BIT_MODEL_TOTAL - 1))) >> RC_MOVE_REDUCING_BITS];
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}
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static inline uint32_t
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rc_bit_0_price(const probability prob)
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{
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return lzma_rc_prices[prob >> RC_MOVE_REDUCING_BITS];
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}
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static inline uint32_t
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rc_bit_1_price(const probability prob)
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{
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return lzma_rc_prices[(prob ^ (RC_BIT_MODEL_TOTAL - 1))
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>> RC_MOVE_REDUCING_BITS];
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}
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static inline uint32_t
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rc_bittree_price(const probability *const probs,
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const uint32_t bit_levels, uint32_t symbol)
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{
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uint32_t price = 0;
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symbol += UINT32_C(1) << bit_levels;
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do {
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const uint32_t bit = symbol & 1;
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symbol >>= 1;
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price += rc_bit_price(probs[symbol], bit);
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} while (symbol != 1);
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return price;
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}
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static inline uint32_t
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rc_bittree_reverse_price(const probability *const probs,
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uint32_t bit_levels, uint32_t symbol)
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{
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uint32_t price = 0;
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uint32_t model_index = 1;
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do {
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const uint32_t bit = symbol & 1;
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symbol >>= 1;
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price += rc_bit_price(probs[model_index], bit);
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model_index = (model_index << 1) + bit;
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} while (--bit_levels != 0);
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return price;
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}
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static inline uint32_t
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rc_direct_price(const uint32_t bits)
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{
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return bits << RC_BIT_PRICE_SHIFT_BITS;
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}
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#endif
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