diff options
Diffstat (limited to 'lib/zstd/compress/fse_compress.c')
| -rw-r--r-- | lib/zstd/compress/fse_compress.c | 59 |
1 files changed, 8 insertions, 51 deletions
diff --git a/lib/zstd/compress/fse_compress.c b/lib/zstd/compress/fse_compress.c index ec5b1ca6d71af6..e46ca6621b488d 100644 --- a/lib/zstd/compress/fse_compress.c +++ b/lib/zstd/compress/fse_compress.c @@ -1,6 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause /* ****************************************************************** * FSE : Finite State Entropy encoder - * Copyright (c) Yann Collet, Facebook, Inc. + * Copyright (c) Meta Platforms, Inc. and affiliates. * * You can contact the author at : * - FSE source repository : https://github.com/Cyan4973/FiniteStateEntropy @@ -26,6 +27,7 @@ #define ZSTD_DEPS_NEED_MALLOC #define ZSTD_DEPS_NEED_MATH64 #include "../common/zstd_deps.h" /* ZSTD_malloc, ZSTD_free, ZSTD_memcpy, ZSTD_memset */ +#include "../common/bits.h" /* ZSTD_highbit32 */ /* ************************************************************** @@ -90,7 +92,7 @@ size_t FSE_buildCTable_wksp(FSE_CTable* ct, assert(tableLog < 16); /* required for threshold strategy to work */ /* For explanations on how to distribute symbol values over the table : - * http://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */ + * https://fastcompression.blogspot.fr/2014/02/fse-distributing-symbol-values.html */ #ifdef __clang_analyzer__ ZSTD_memset(tableSymbol, 0, sizeof(*tableSymbol) * tableSize); /* useless initialization, just to keep scan-build happy */ @@ -191,7 +193,7 @@ size_t FSE_buildCTable_wksp(FSE_CTable* ct, break; default : assert(normalizedCounter[s] > 1); - { U32 const maxBitsOut = tableLog - BIT_highbit32 ((U32)normalizedCounter[s]-1); + { U32 const maxBitsOut = tableLog - ZSTD_highbit32 ((U32)normalizedCounter[s]-1); U32 const minStatePlus = (U32)normalizedCounter[s] << maxBitsOut; symbolTT[s].deltaNbBits = (maxBitsOut << 16) - minStatePlus; symbolTT[s].deltaFindState = (int)(total - (unsigned)normalizedCounter[s]); @@ -342,21 +344,11 @@ size_t FSE_writeNCount (void* buffer, size_t bufferSize, * FSE Compression Code ****************************************************************/ -FSE_CTable* FSE_createCTable (unsigned maxSymbolValue, unsigned tableLog) -{ - size_t size; - if (tableLog > FSE_TABLELOG_ABSOLUTE_MAX) tableLog = FSE_TABLELOG_ABSOLUTE_MAX; - size = FSE_CTABLE_SIZE_U32 (tableLog, maxSymbolValue) * sizeof(U32); - return (FSE_CTable*)ZSTD_malloc(size); -} - -void FSE_freeCTable (FSE_CTable* ct) { ZSTD_free(ct); } - /* provides the minimum logSize to safely represent a distribution */ static unsigned FSE_minTableLog(size_t srcSize, unsigned maxSymbolValue) { - U32 minBitsSrc = BIT_highbit32((U32)(srcSize)) + 1; - U32 minBitsSymbols = BIT_highbit32(maxSymbolValue) + 2; + U32 minBitsSrc = ZSTD_highbit32((U32)(srcSize)) + 1; + U32 minBitsSymbols = ZSTD_highbit32(maxSymbolValue) + 2; U32 minBits = minBitsSrc < minBitsSymbols ? minBitsSrc : minBitsSymbols; assert(srcSize > 1); /* Not supported, RLE should be used instead */ return minBits; @@ -364,7 +356,7 @@ static unsigned FSE_minTableLog(size_t srcSize, unsigned maxSymbolValue) unsigned FSE_optimalTableLog_internal(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, unsigned minus) { - U32 maxBitsSrc = BIT_highbit32((U32)(srcSize - 1)) - minus; + U32 maxBitsSrc = ZSTD_highbit32((U32)(srcSize - 1)) - minus; U32 tableLog = maxTableLog; U32 minBits = FSE_minTableLog(srcSize, maxSymbolValue); assert(srcSize > 1); /* Not supported, RLE should be used instead */ @@ -532,40 +524,6 @@ size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog, return tableLog; } - -/* fake FSE_CTable, for raw (uncompressed) input */ -size_t FSE_buildCTable_raw (FSE_CTable* ct, unsigned nbBits) -{ - const unsigned tableSize = 1 << nbBits; - const unsigned tableMask = tableSize - 1; - const unsigned maxSymbolValue = tableMask; - void* const ptr = ct; - U16* const tableU16 = ( (U16*) ptr) + 2; - void* const FSCT = ((U32*)ptr) + 1 /* header */ + (tableSize>>1); /* assumption : tableLog >= 1 */ - FSE_symbolCompressionTransform* const symbolTT = (FSE_symbolCompressionTransform*) (FSCT); - unsigned s; - - /* Sanity checks */ - if (nbBits < 1) return ERROR(GENERIC); /* min size */ - - /* header */ - tableU16[-2] = (U16) nbBits; - tableU16[-1] = (U16) maxSymbolValue; - - /* Build table */ - for (s=0; s<tableSize; s++) - tableU16[s] = (U16)(tableSize + s); - - /* Build Symbol Transformation Table */ - { const U32 deltaNbBits = (nbBits << 16) - (1 << nbBits); - for (s=0; s<=maxSymbolValue; s++) { - symbolTT[s].deltaNbBits = deltaNbBits; - symbolTT[s].deltaFindState = s-1; - } } - - return 0; -} - /* fake FSE_CTable, for rle input (always same symbol) */ size_t FSE_buildCTable_rle (FSE_CTable* ct, BYTE symbolValue) { @@ -664,5 +622,4 @@ size_t FSE_compress_usingCTable (void* dst, size_t dstSize, size_t FSE_compressBound(size_t size) { return FSE_COMPRESSBOUND(size); } - #endif /* FSE_COMMONDEFS_ONLY */ |