/* ****************************************************************** * huff0 huffman decoder, * part of Finite State Entropy library * Copyright (c) Meta Platforms, Inc. and affiliates. * * You can contact the author at : * - FSE+HUF source repository : https://github.com/Cyan4973/FiniteStateEntropy * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. ****************************************************************** */ /* ************************************************************** * Dependencies ****************************************************************/ #include "zstd_deps.h" /* ZSTD_memcpy, ZSTD_memset */ #include "compiler.h" #include "bitstream.h" /* BIT_* */ #include "fse.h" /* to compress headers */ #include "huf.h" #include "error_private.h" #include "zstd_internal.h" #include "bits.h" /* ZSTD_highbit32, ZSTD_countTrailingZeros64 */ /* ************************************************************** * Constants ****************************************************************/ #define HUF_DECODER_FAST_TABLELOG 11 /* ************************************************************** * Macros ****************************************************************/ /* These two optional macros force the use one way or another of the two * Huffman decompression implementations. You can't force in both directions * at the same time. */ #if defined(HUF_FORCE_DECOMPRESS_X1) && \ defined(HUF_FORCE_DECOMPRESS_X2) #error "Cannot force the use of the X1 and X2 decoders at the same time!" #endif /* When DYNAMIC_BMI2 is enabled, fast decoders are only called when bmi2 is * supported at runtime, so we can add the BMI2 target attribute. * When it is disabled, we will still get BMI2 if it is enabled statically. */ #if DYNAMIC_BMI2 # define HUF_FAST_BMI2_ATTRS BMI2_TARGET_ATTRIBUTE #else # define HUF_FAST_BMI2_ATTRS #endif #ifdef __cplusplus # define HUF_EXTERN_C extern "C" #else # define HUF_EXTERN_C #endif #define HUF_ASM_DECL HUF_EXTERN_C #if DYNAMIC_BMI2 # define HUF_NEED_BMI2_FUNCTION 1 #else # define HUF_NEED_BMI2_FUNCTION 0 #endif /* ************************************************************** * Error Management ****************************************************************/ #define HUF_isError ERR_isError /* ************************************************************** * Byte alignment for workSpace management ****************************************************************/ #define HUF_ALIGN(x, a) HUF_ALIGN_MASK((x), (a) - 1) #define HUF_ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) /* ************************************************************** * BMI2 Variant Wrappers ****************************************************************/ typedef size_t (*HUF_DecompressUsingDTableFn)(void *dst, size_t dstSize, const void *cSrc, size_t cSrcSize, const HUF_DTable *DTable); #if DYNAMIC_BMI2 #define HUF_DGEN(fn) \ \ static size_t fn##_default( \ void* dst, size_t dstSize, \ const void* cSrc, size_t cSrcSize, \ const HUF_DTable* DTable) \ { \ return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable); \ } \ \ static BMI2_TARGET_ATTRIBUTE size_t fn##_bmi2( \ void* dst, size_t dstSize, \ const void* cSrc, size_t cSrcSize, \ const HUF_DTable* DTable) \ { \ return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable); \ } \ \ static size_t fn(void* dst, size_t dstSize, void const* cSrc, \ size_t cSrcSize, HUF_DTable const* DTable, int flags) \ { \ if (flags & HUF_flags_bmi2) { \ return fn##_bmi2(dst, dstSize, cSrc, cSrcSize, DTable); \ } \ return fn##_default(dst, dstSize, cSrc, cSrcSize, DTable); \ } #else #define HUF_DGEN(fn) \ static size_t fn(void* dst, size_t dstSize, void const* cSrc, \ size_t cSrcSize, HUF_DTable const* DTable, int flags) \ { \ (void)flags; \ return fn##_body(dst, dstSize, cSrc, cSrcSize, DTable); \ } #endif /*-***************************/ /* generic DTableDesc */ /*-***************************/ typedef struct { BYTE maxTableLog; BYTE tableType; BYTE tableLog; BYTE reserved; } DTableDesc; static DTableDesc HUF_getDTableDesc(const HUF_DTable* table) { DTableDesc dtd; ZSTD_memcpy(&dtd, table, sizeof(dtd)); return dtd; } static size_t HUF_initFastDStream(BYTE const* ip) { BYTE const lastByte = ip[7]; size_t const bitsConsumed = lastByte ? 8 - ZSTD_highbit32(lastByte) : 0; size_t const value = MEM_readLEST(ip) | 1; assert(bitsConsumed <= 8); assert(sizeof(size_t) == 8); return value << bitsConsumed; } /** * The input/output arguments to the Huffman fast decoding loop: * * ip [in/out] - The input pointers, must be updated to reflect what is consumed. * op [in/out] - The output pointers, must be updated to reflect what is written. * bits [in/out] - The bitstream containers, must be updated to reflect the current state. * dt [in] - The decoding table. * ilimit [in] - The input limit, stop when any input pointer is below ilimit. * oend [in] - The end of the output stream. op[3] must not cross oend. * iend [in] - The end of each input stream. ip[i] may cross iend[i], * as long as it is above ilimit, but that indicates corruption. */ typedef struct { BYTE const* ip[4]; BYTE* op[4]; U64 bits[4]; void const* dt; BYTE const* ilimit; BYTE* oend; BYTE const* iend[4]; } HUF_DecompressFastArgs; typedef void (*HUF_DecompressFastLoopFn)(HUF_DecompressFastArgs*); /** * Initializes args for the fast decoding loop. * @returns 1 on success * 0 if the fallback implementation should be used. * Or an error code on failure. */ static size_t HUF_DecompressFastArgs_init(HUF_DecompressFastArgs* args, void* dst, size_t dstSize, void const* src, size_t srcSize, const HUF_DTable* DTable) { void const* dt = DTable + 1; U32 const dtLog = HUF_getDTableDesc(DTable).tableLog; const BYTE* const ilimit = (const BYTE*)src + 6 + 8; BYTE* const oend = (BYTE*)dst + dstSize; /* The fast decoding loop assumes 64-bit little-endian. * This condition is false on x32. */ if (!MEM_isLittleEndian() || MEM_32bits()) return 0; /* strict minimum : jump table + 1 byte per stream */ if (srcSize < 10) return ERROR(corruption_detected); /* Must have at least 8 bytes per stream because we don't handle initializing smaller bit containers. * If table log is not correct at this point, fallback to the old decoder. * On small inputs we don't have enough data to trigger the fast loop, so use the old decoder. */ if (dtLog != HUF_DECODER_FAST_TABLELOG) return 0; /* Read the jump table. */ { const BYTE* const istart = (const BYTE*)src; size_t const length1 = MEM_readLE16(istart); size_t const length2 = MEM_readLE16(istart+2); size_t const length3 = MEM_readLE16(istart+4); size_t const length4 = srcSize - (length1 + length2 + length3 + 6); args->iend[0] = istart + 6; /* jumpTable */ args->iend[1] = args->iend[0] + length1; args->iend[2] = args->iend[1] + length2; args->iend[3] = args->iend[2] + length3; /* HUF_initFastDStream() requires this, and this small of an input * won't benefit from the ASM loop anyways. * length1 must be >= 16 so that ip[0] >= ilimit before the loop * starts. */ if (length1 < 16 || length2 < 8 || length3 < 8 || length4 < 8) return 0; if (length4 > srcSize) return ERROR(corruption_detected); /* overflow */ } /* ip[] contains the position that is currently loaded into bits[]. */ args->ip[0] = args->iend[1] - sizeof(U64); args->ip[1] = args->iend[2] - sizeof(U64); args->ip[2] = args->iend[3] - sizeof(U64); args->ip[3] = (BYTE const*)src + srcSize - sizeof(U64); /* op[] contains the output pointers. */ args->op[0] = (BYTE*)dst; args->op[1] = args->op[0] + (dstSize+3)/4; args->op[2] = args->op[1] + (dstSize+3)/4; args->op[3] = args->op[2] + (dstSize+3)/4; /* No point to call the ASM loop for tiny outputs. */ if (args->op[3] >= oend) return 0; /* bits[] is the bit container. * It is read from the MSB down to the LSB. * It is shifted left as it is read, and zeros are * shifted in. After the lowest valid bit a 1 is * set, so that CountTrailingZeros(bits[]) can be used * to count how many bits we've consumed. */ args->bits[0] = HUF_initFastDStream(args->ip[0]); args->bits[1] = HUF_initFastDStream(args->ip[1]); args->bits[2] = HUF_initFastDStream(args->ip[2]); args->bits[3] = HUF_initFastDStream(args->ip[3]); /* If ip[] >= ilimit, it is guaranteed to be safe to * reload bits[]. It may be beyond its section, but is * guaranteed to be valid (>= istart). */ args->ilimit = ilimit; args->oend = oend; args->dt = dt; return 1; } static size_t HUF_initRemainingDStream(BIT_DStream_t* bit, HUF_DecompressFastArgs const* args, int stream, BYTE* segmentEnd) { /* Validate that we haven't overwritten. */ if (args->op[stream] > segmentEnd) return ERROR(corruption_detected); /* Validate that we haven't read beyond iend[]. * Note that ip[] may be < iend[] because the MSB is * the next bit to read, and we may have consumed 100% * of the stream, so down to iend[i] - 8 is valid. */ if (args->ip[stream] < args->iend[stream] - 8) return ERROR(corruption_detected); /* Construct the BIT_DStream_t. */ assert(sizeof(size_t) == 8); bit->bitContainer = MEM_readLEST(args->ip[stream]); bit->bitsConsumed = ZSTD_countTrailingZeros64(args->bits[stream]); bit->start = (const char*)args->iend[0]; bit->limitPtr = bit->start + sizeof(size_t); bit->ptr = (const char*)args->ip[stream]; return 0; } #ifndef HUF_FORCE_DECOMPRESS_X2 /*-***************************/ /* single-symbol decoding */ /*-***************************/ typedef struct { BYTE nbBits; BYTE byte; } HUF_DEltX1; /* single-symbol decoding */ /** * Packs 4 HUF_DEltX1 structs into a U64. This is used to lay down 4 entries at * a time. */ static U64 HUF_DEltX1_set4(BYTE symbol, BYTE nbBits) { U64 D4; if (MEM_isLittleEndian()) { D4 = (U64)((symbol << 8) + nbBits); } else { D4 = (U64)(symbol + (nbBits << 8)); } assert(D4 < (1U << 16)); D4 *= 0x0001000100010001ULL; return D4; } /** * Increase the tableLog to targetTableLog and rescales the stats. * If tableLog > targetTableLog this is a no-op. * @returns New tableLog */ static U32 HUF_rescaleStats(BYTE* huffWeight, U32* rankVal, U32 nbSymbols, U32 tableLog, U32 targetTableLog) { if (tableLog > targetTableLog) return tableLog; if (tableLog < targetTableLog) { U32 const scale = targetTableLog - tableLog; U32 s; /* Increase the weight for all non-zero probability symbols by scale. */ for (s = 0; s < nbSymbols; ++s) { huffWeight[s] += (BYTE)((huffWeight[s] == 0) ? 0 : scale); } /* Update rankVal to reflect the new weights. * All weights except 0 get moved to weight + scale. * Weights [1, scale] are empty. */ for (s = targetTableLog; s > scale; --s) { rankVal[s] = rankVal[s - scale]; } for (s = scale; s > 0; --s) { rankVal[s] = 0; } } return targetTableLog; } typedef struct { U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1]; U32 rankStart[HUF_TABLELOG_ABSOLUTEMAX + 1]; U32 statsWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32]; BYTE symbols[HUF_SYMBOLVALUE_MAX + 1]; BYTE huffWeight[HUF_SYMBOLVALUE_MAX + 1]; } HUF_ReadDTableX1_Workspace; size_t HUF_readDTableX1_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags) { U32 tableLog = 0; U32 nbSymbols = 0; size_t iSize; void* const dtPtr = DTable + 1; HUF_DEltX1* const dt = (HUF_DEltX1*)dtPtr; HUF_ReadDTableX1_Workspace* wksp = (HUF_ReadDTableX1_Workspace*)workSpace; DEBUG_STATIC_ASSERT(HUF_DECOMPRESS_WORKSPACE_SIZE >= sizeof(*wksp)); if (sizeof(*wksp) > wkspSize) return ERROR(tableLog_tooLarge); DEBUG_STATIC_ASSERT(sizeof(DTableDesc) == sizeof(HUF_DTable)); /* ZSTD_memset(huffWeight, 0, sizeof(huffWeight)); */ /* is not necessary, even though some analyzer complain ... */ iSize = HUF_readStats_wksp(wksp->huffWeight, HUF_SYMBOLVALUE_MAX + 1, wksp->rankVal, &nbSymbols, &tableLog, src, srcSize, wksp->statsWksp, sizeof(wksp->statsWksp), flags); if (HUF_isError(iSize)) return iSize; /* Table header */ { DTableDesc dtd = HUF_getDTableDesc(DTable); U32 const maxTableLog = dtd.maxTableLog + 1; U32 const targetTableLog = MIN(maxTableLog, HUF_DECODER_FAST_TABLELOG); tableLog = HUF_rescaleStats(wksp->huffWeight, wksp->rankVal, nbSymbols, tableLog, targetTableLog); if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge); /* DTable too small, Huffman tree cannot fit in */ dtd.tableType = 0; dtd.tableLog = (BYTE)tableLog; ZSTD_memcpy(DTable, &dtd, sizeof(dtd)); } /* Compute symbols and rankStart given rankVal: * * rankVal already contains the number of values of each weight. * * symbols contains the symbols ordered by weight. First are the rankVal[0] * weight 0 symbols, followed by the rankVal[1] weight 1 symbols, and so on. * symbols[0] is filled (but unused) to avoid a branch. * * rankStart contains the offset where each rank belongs in the DTable. * rankStart[0] is not filled because there are no entries in the table for * weight 0. */ { int n; U32 nextRankStart = 0; int const unroll = 4; int const nLimit = (int)nbSymbols - unroll + 1; for (n=0; n<(int)tableLog+1; n++) { U32 const curr = nextRankStart; nextRankStart += wksp->rankVal[n]; wksp->rankStart[n] = curr; } for (n=0; n < nLimit; n += unroll) { int u; for (u=0; u < unroll; ++u) { size_t const w = wksp->huffWeight[n+u]; wksp->symbols[wksp->rankStart[w]++] = (BYTE)(n+u); } } for (; n < (int)nbSymbols; ++n) { size_t const w = wksp->huffWeight[n]; wksp->symbols[wksp->rankStart[w]++] = (BYTE)n; } } /* fill DTable * We fill all entries of each weight in order. * That way length is a constant for each iteration of the outer loop. * We can switch based on the length to a different inner loop which is * optimized for that particular case. */ { U32 w; int symbol = wksp->rankVal[0]; int rankStart = 0; for (w=1; wrankVal[w]; int const length = (1 << w) >> 1; int uStart = rankStart; BYTE const nbBits = (BYTE)(tableLog + 1 - w); int s; int u; switch (length) { case 1: for (s=0; ssymbols[symbol + s]; D.nbBits = nbBits; dt[uStart] = D; uStart += 1; } break; case 2: for (s=0; ssymbols[symbol + s]; D.nbBits = nbBits; dt[uStart+0] = D; dt[uStart+1] = D; uStart += 2; } break; case 4: for (s=0; ssymbols[symbol + s], nbBits); MEM_write64(dt + uStart, D4); uStart += 4; } break; case 8: for (s=0; ssymbols[symbol + s], nbBits); MEM_write64(dt + uStart, D4); MEM_write64(dt + uStart + 4, D4); uStart += 8; } break; default: for (s=0; ssymbols[symbol + s], nbBits); for (u=0; u < length; u += 16) { MEM_write64(dt + uStart + u + 0, D4); MEM_write64(dt + uStart + u + 4, D4); MEM_write64(dt + uStart + u + 8, D4); MEM_write64(dt + uStart + u + 12, D4); } assert(u == length); uStart += length; } break; } symbol += symbolCount; rankStart += symbolCount * length; } } return iSize; } FORCE_INLINE_TEMPLATE BYTE HUF_decodeSymbolX1(BIT_DStream_t* Dstream, const HUF_DEltX1* dt, const U32 dtLog) { size_t const val = BIT_lookBitsFast(Dstream, dtLog); /* note : dtLog >= 1 */ BYTE const c = dt[val].byte; BIT_skipBits(Dstream, dt[val].nbBits); return c; } #define HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) \ *ptr++ = HUF_decodeSymbolX1(DStreamPtr, dt, dtLog) #define HUF_DECODE_SYMBOLX1_1(ptr, DStreamPtr) \ if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \ HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) #define HUF_DECODE_SYMBOLX1_2(ptr, DStreamPtr) \ if (MEM_64bits()) \ HUF_DECODE_SYMBOLX1_0(ptr, DStreamPtr) HINT_INLINE size_t HUF_decodeStreamX1(BYTE* p, BIT_DStream_t* const bitDPtr, BYTE* const pEnd, const HUF_DEltX1* const dt, const U32 dtLog) { BYTE* const pStart = p; /* up to 4 symbols at a time */ if ((pEnd - p) > 3) { while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-3)) { HUF_DECODE_SYMBOLX1_2(p, bitDPtr); HUF_DECODE_SYMBOLX1_1(p, bitDPtr); HUF_DECODE_SYMBOLX1_2(p, bitDPtr); HUF_DECODE_SYMBOLX1_0(p, bitDPtr); } } else { BIT_reloadDStream(bitDPtr); } /* [0-3] symbols remaining */ if (MEM_32bits()) while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd)) HUF_DECODE_SYMBOLX1_0(p, bitDPtr); /* no more data to retrieve from bitstream, no need to reload */ while (p < pEnd) HUF_DECODE_SYMBOLX1_0(p, bitDPtr); return (size_t)(pEnd-pStart); } FORCE_INLINE_TEMPLATE size_t HUF_decompress1X1_usingDTable_internal_body( void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable) { BYTE* op = (BYTE*)dst; BYTE* const oend = op + dstSize; const void* dtPtr = DTable + 1; const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr; BIT_DStream_t bitD; DTableDesc const dtd = HUF_getDTableDesc(DTable); U32 const dtLog = dtd.tableLog; CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) ); HUF_decodeStreamX1(op, &bitD, oend, dt, dtLog); if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected); return dstSize; } /* HUF_decompress4X1_usingDTable_internal_body(): * Conditions : * @dstSize >= 6 */ FORCE_INLINE_TEMPLATE size_t HUF_decompress4X1_usingDTable_internal_body( void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable) { /* Check */ if (cSrcSize < 10) return ERROR(corruption_detected); /* strict minimum : jump table + 1 byte per stream */ { const BYTE* const istart = (const BYTE*) cSrc; BYTE* const ostart = (BYTE*) dst; BYTE* const oend = ostart + dstSize; BYTE* const olimit = oend - 3; const void* const dtPtr = DTable + 1; const HUF_DEltX1* const dt = (const HUF_DEltX1*)dtPtr; /* Init */ BIT_DStream_t bitD1; BIT_DStream_t bitD2; BIT_DStream_t bitD3; BIT_DStream_t bitD4; size_t const length1 = MEM_readLE16(istart); size_t const length2 = MEM_readLE16(istart+2); size_t const length3 = MEM_readLE16(istart+4); size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6); const BYTE* const istart1 = istart + 6; /* jumpTable */ const BYTE* const istart2 = istart1 + length1; const BYTE* const istart3 = istart2 + length2; const BYTE* const istart4 = istart3 + length3; const size_t segmentSize = (dstSize+3) / 4; BYTE* const opStart2 = ostart + segmentSize; BYTE* const opStart3 = opStart2 + segmentSize; BYTE* const opStart4 = opStart3 + segmentSize; BYTE* op1 = ostart; BYTE* op2 = opStart2; BYTE* op3 = opStart3; BYTE* op4 = opStart4; DTableDesc const dtd = HUF_getDTableDesc(DTable); U32 const dtLog = dtd.tableLog; U32 endSignal = 1; if (length4 > cSrcSize) return ERROR(corruption_detected); /* overflow */ if (opStart4 > oend) return ERROR(corruption_detected); /* overflow */ if (dstSize < 6) return ERROR(corruption_detected); /* stream 4-split doesn't work */ CHECK_F( BIT_initDStream(&bitD1, istart1, length1) ); CHECK_F( BIT_initDStream(&bitD2, istart2, length2) ); CHECK_F( BIT_initDStream(&bitD3, istart3, length3) ); CHECK_F( BIT_initDStream(&bitD4, istart4, length4) ); /* up to 16 symbols per loop (4 symbols per stream) in 64-bit mode */ if ((size_t)(oend - op4) >= sizeof(size_t)) { for ( ; (endSignal) & (op4 < olimit) ; ) { HUF_DECODE_SYMBOLX1_2(op1, &bitD1); HUF_DECODE_SYMBOLX1_2(op2, &bitD2); HUF_DECODE_SYMBOLX1_2(op3, &bitD3); HUF_DECODE_SYMBOLX1_2(op4, &bitD4); HUF_DECODE_SYMBOLX1_1(op1, &bitD1); HUF_DECODE_SYMBOLX1_1(op2, &bitD2); HUF_DECODE_SYMBOLX1_1(op3, &bitD3); HUF_DECODE_SYMBOLX1_1(op4, &bitD4); HUF_DECODE_SYMBOLX1_2(op1, &bitD1); HUF_DECODE_SYMBOLX1_2(op2, &bitD2); HUF_DECODE_SYMBOLX1_2(op3, &bitD3); HUF_DECODE_SYMBOLX1_2(op4, &bitD4); HUF_DECODE_SYMBOLX1_0(op1, &bitD1); HUF_DECODE_SYMBOLX1_0(op2, &bitD2); HUF_DECODE_SYMBOLX1_0(op3, &bitD3); HUF_DECODE_SYMBOLX1_0(op4, &bitD4); endSignal &= BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished; endSignal &= BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished; endSignal &= BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished; endSignal &= BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished; } } /* check corruption */ /* note : should not be necessary : op# advance in lock step, and we control op4. * but curiously, binary generated by gcc 7.2 & 7.3 with -mbmi2 runs faster when >=1 test is present */ if (op1 > opStart2) return ERROR(corruption_detected); if (op2 > opStart3) return ERROR(corruption_detected); if (op3 > opStart4) return ERROR(corruption_detected); /* note : op4 supposed already verified within main loop */ /* finish bitStreams one by one */ HUF_decodeStreamX1(op1, &bitD1, opStart2, dt, dtLog); HUF_decodeStreamX1(op2, &bitD2, opStart3, dt, dtLog); HUF_decodeStreamX1(op3, &bitD3, opStart4, dt, dtLog); HUF_decodeStreamX1(op4, &bitD4, oend, dt, dtLog); /* check */ { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4); if (!endCheck) return ERROR(corruption_detected); } /* decoded size */ return dstSize; } } #if HUF_NEED_BMI2_FUNCTION static BMI2_TARGET_ATTRIBUTE size_t HUF_decompress4X1_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc, size_t cSrcSize, HUF_DTable const* DTable) { return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); } #endif static size_t HUF_decompress4X1_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc, size_t cSrcSize, HUF_DTable const* DTable) { return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); } #if ZSTD_ENABLE_ASM_X86_64_BMI2 HUF_ASM_DECL void HUF_decompress4X1_usingDTable_internal_fast_asm_loop(HUF_DecompressFastArgs* args) ZSTDLIB_HIDDEN; #endif static HUF_FAST_BMI2_ATTRS void HUF_decompress4X1_usingDTable_internal_fast_c_loop(HUF_DecompressFastArgs* args) { U64 bits[4]; BYTE const* ip[4]; BYTE* op[4]; U16 const* const dtable = (U16 const*)args->dt; BYTE* const oend = args->oend; BYTE const* const ilimit = args->ilimit; /* Copy the arguments to local variables */ ZSTD_memcpy(&bits, &args->bits, sizeof(bits)); ZSTD_memcpy(&ip, &args->ip, sizeof(ip)); ZSTD_memcpy(&op, &args->op, sizeof(op)); assert(MEM_isLittleEndian()); assert(!MEM_32bits()); for (;;) { BYTE* olimit; int stream; int symbol; /* Assert loop preconditions */ #ifndef NDEBUG for (stream = 0; stream < 4; ++stream) { assert(op[stream] <= (stream == 3 ? oend : op[stream + 1])); assert(ip[stream] >= ilimit); } #endif /* Compute olimit */ { /* Each iteration produces 5 output symbols per stream */ size_t const oiters = (size_t)(oend - op[3]) / 5; /* Each iteration consumes up to 11 bits * 5 = 55 bits < 7 bytes * per stream. */ size_t const iiters = (size_t)(ip[0] - ilimit) / 7; /* We can safely run iters iterations before running bounds checks */ size_t const iters = MIN(oiters, iiters); size_t const symbols = iters * 5; /* We can simply check that op[3] < olimit, instead of checking all * of our bounds, since we can't hit the other bounds until we've run * iters iterations, which only happens when op[3] == olimit. */ olimit = op[3] + symbols; /* Exit fast decoding loop once we get close to the end. */ if (op[3] + 20 > olimit) break; /* Exit the decoding loop if any input pointer has crossed the * previous one. This indicates corruption, and a precondition * to our loop is that ip[i] >= ip[0]. */ for (stream = 1; stream < 4; ++stream) { if (ip[stream] < ip[stream - 1]) goto _out; } } #ifndef NDEBUG for (stream = 1; stream < 4; ++stream) { assert(ip[stream] >= ip[stream - 1]); } #endif do { /* Decode 5 symbols in each of the 4 streams */ for (symbol = 0; symbol < 5; ++symbol) { for (stream = 0; stream < 4; ++stream) { int const index = (int)(bits[stream] >> 53); int const entry = (int)dtable[index]; bits[stream] <<= (entry & 63); op[stream][symbol] = (BYTE)((entry >> 8) & 0xFF); } } /* Reload the bitstreams */ for (stream = 0; stream < 4; ++stream) { int const ctz = ZSTD_countTrailingZeros64(bits[stream]); int const nbBits = ctz & 7; int const nbBytes = ctz >> 3; op[stream] += 5; ip[stream] -= nbBytes; bits[stream] = MEM_read64(ip[stream]) | 1; bits[stream] <<= nbBits; } } while (op[3] < olimit); } _out: /* Save the final values of each of the state variables back to args. */ ZSTD_memcpy(&args->bits, &bits, sizeof(bits)); ZSTD_memcpy(&args->ip, &ip, sizeof(ip)); ZSTD_memcpy(&args->op, &op, sizeof(op)); } /** * @returns @p dstSize on success (>= 6) * 0 if the fallback implementation should be used * An error if an error occurred */ static HUF_FAST_BMI2_ATTRS size_t HUF_decompress4X1_usingDTable_internal_fast( void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, HUF_DecompressFastLoopFn loopFn) { void const* dt = DTable + 1; const BYTE* const iend = (const BYTE*)cSrc + 6; BYTE* const oend = (BYTE*)dst + dstSize; HUF_DecompressFastArgs args; { size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable); FORWARD_IF_ERROR(ret, "Failed to init fast loop args"); if (ret == 0) return 0; } assert(args.ip[0] >= args.ilimit); loopFn(&args); /* Our loop guarantees that ip[] >= ilimit and that we haven't * overwritten any op[]. */ assert(args.ip[0] >= iend); assert(args.ip[1] >= iend); assert(args.ip[2] >= iend); assert(args.ip[3] >= iend); assert(args.op[3] <= oend); (void)iend; /* finish bit streams one by one. */ { size_t const segmentSize = (dstSize+3) / 4; BYTE* segmentEnd = (BYTE*)dst; int i; for (i = 0; i < 4; ++i) { BIT_DStream_t bit; if (segmentSize <= (size_t)(oend - segmentEnd)) segmentEnd += segmentSize; else segmentEnd = oend; FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption"); /* Decompress and validate that we've produced exactly the expected length. */ args.op[i] += HUF_decodeStreamX1(args.op[i], &bit, segmentEnd, (HUF_DEltX1 const*)dt, HUF_DECODER_FAST_TABLELOG); if (args.op[i] != segmentEnd) return ERROR(corruption_detected); } } /* decoded size */ assert(dstSize != 0); return dstSize; } HUF_DGEN(HUF_decompress1X1_usingDTable_internal) static size_t HUF_decompress4X1_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc, size_t cSrcSize, HUF_DTable const* DTable, int flags) { HUF_DecompressUsingDTableFn fallbackFn = HUF_decompress4X1_usingDTable_internal_default; HUF_DecompressFastLoopFn loopFn = HUF_decompress4X1_usingDTable_internal_fast_c_loop; #if DYNAMIC_BMI2 if (flags & HUF_flags_bmi2) { fallbackFn = HUF_decompress4X1_usingDTable_internal_bmi2; # if ZSTD_ENABLE_ASM_X86_64_BMI2 if (!(flags & HUF_flags_disableAsm)) { loopFn = HUF_decompress4X1_usingDTable_internal_fast_asm_loop; } # endif } else { return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); } #endif #if ZSTD_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__) if (!(flags & HUF_flags_disableAsm)) { loopFn = HUF_decompress4X1_usingDTable_internal_fast_asm_loop; } #endif if (!(flags & HUF_flags_disableFast)) { size_t const ret = HUF_decompress4X1_usingDTable_internal_fast(dst, dstSize, cSrc, cSrcSize, DTable, loopFn); if (ret != 0) return ret; } return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); } static size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) { const BYTE* ip = (const BYTE*) cSrc; size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags); if (HUF_isError(hSize)) return hSize; if (hSize >= cSrcSize) return ERROR(srcSize_wrong); ip += hSize; cSrcSize -= hSize; return HUF_decompress4X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags); } #endif /* HUF_FORCE_DECOMPRESS_X2 */ #ifndef HUF_FORCE_DECOMPRESS_X1 /* *************************/ /* double-symbols decoding */ /* *************************/ typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX2; /* double-symbols decoding */ typedef struct { BYTE symbol; } sortedSymbol_t; typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1]; typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX]; /** * Constructs a HUF_DEltX2 in a U32. */ static U32 HUF_buildDEltX2U32(U32 symbol, U32 nbBits, U32 baseSeq, int level) { U32 seq; DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, sequence) == 0); DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, nbBits) == 2); DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, length) == 3); DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U32)); if (MEM_isLittleEndian()) { seq = level == 1 ? symbol : (baseSeq + (symbol << 8)); return seq + (nbBits << 16) + ((U32)level << 24); } else { seq = level == 1 ? (symbol << 8) : ((baseSeq << 8) + symbol); return (seq << 16) + (nbBits << 8) + (U32)level; } } /** * Constructs a HUF_DEltX2. */ static HUF_DEltX2 HUF_buildDEltX2(U32 symbol, U32 nbBits, U32 baseSeq, int level) { HUF_DEltX2 DElt; U32 const val = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level); DEBUG_STATIC_ASSERT(sizeof(DElt) == sizeof(val)); ZSTD_memcpy(&DElt, &val, sizeof(val)); return DElt; } /** * Constructs 2 HUF_DEltX2s and packs them into a U64. */ static U64 HUF_buildDEltX2U64(U32 symbol, U32 nbBits, U16 baseSeq, int level) { U32 DElt = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level); return (U64)DElt + ((U64)DElt << 32); } /** * Fills the DTable rank with all the symbols from [begin, end) that are each * nbBits long. * * @param DTableRank The start of the rank in the DTable. * @param begin The first symbol to fill (inclusive). * @param end The last symbol to fill (exclusive). * @param nbBits Each symbol is nbBits long. * @param tableLog The table log. * @param baseSeq If level == 1 { 0 } else { the first level symbol } * @param level The level in the table. Must be 1 or 2. */ static void HUF_fillDTableX2ForWeight( HUF_DEltX2* DTableRank, sortedSymbol_t const* begin, sortedSymbol_t const* end, U32 nbBits, U32 tableLog, U16 baseSeq, int const level) { U32 const length = 1U << ((tableLog - nbBits) & 0x1F /* quiet static-analyzer */); const sortedSymbol_t* ptr; assert(level >= 1 && level <= 2); switch (length) { case 1: for (ptr = begin; ptr != end; ++ptr) { HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level); *DTableRank++ = DElt; } break; case 2: for (ptr = begin; ptr != end; ++ptr) { HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level); DTableRank[0] = DElt; DTableRank[1] = DElt; DTableRank += 2; } break; case 4: for (ptr = begin; ptr != end; ++ptr) { U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level); ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2)); DTableRank += 4; } break; case 8: for (ptr = begin; ptr != end; ++ptr) { U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level); ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2)); DTableRank += 8; } break; default: for (ptr = begin; ptr != end; ++ptr) { U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level); HUF_DEltX2* const DTableRankEnd = DTableRank + length; for (; DTableRank != DTableRankEnd; DTableRank += 8) { ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2)); } } break; } } /* HUF_fillDTableX2Level2() : * `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */ static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 targetLog, const U32 consumedBits, const U32* rankVal, const int minWeight, const int maxWeight1, const sortedSymbol_t* sortedSymbols, U32 const* rankStart, U32 nbBitsBaseline, U16 baseSeq) { /* Fill skipped values (all positions up to rankVal[minWeight]). * These are positions only get a single symbol because the combined weight * is too large. */ if (minWeight>1) { U32 const length = 1U << ((targetLog - consumedBits) & 0x1F /* quiet static-analyzer */); U64 const DEltX2 = HUF_buildDEltX2U64(baseSeq, consumedBits, /* baseSeq */ 0, /* level */ 1); int const skipSize = rankVal[minWeight]; assert(length > 1); assert((U32)skipSize < length); switch (length) { case 2: assert(skipSize == 1); ZSTD_memcpy(DTable, &DEltX2, sizeof(DEltX2)); break; case 4: assert(skipSize <= 4); ZSTD_memcpy(DTable + 0, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTable + 2, &DEltX2, sizeof(DEltX2)); break; default: { int i; for (i = 0; i < skipSize; i += 8) { ZSTD_memcpy(DTable + i + 0, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTable + i + 2, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTable + i + 4, &DEltX2, sizeof(DEltX2)); ZSTD_memcpy(DTable + i + 6, &DEltX2, sizeof(DEltX2)); } } } } /* Fill each of the second level symbols by weight. */ { int w; for (w = minWeight; w < maxWeight1; ++w) { int const begin = rankStart[w]; int const end = rankStart[w+1]; U32 const nbBits = nbBitsBaseline - w; U32 const totalBits = nbBits + consumedBits; HUF_fillDTableX2ForWeight( DTable + rankVal[w], sortedSymbols + begin, sortedSymbols + end, totalBits, targetLog, baseSeq, /* level */ 2); } } } static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog, const sortedSymbol_t* sortedList, const U32* rankStart, rankValCol_t* rankValOrigin, const U32 maxWeight, const U32 nbBitsBaseline) { U32* const rankVal = rankValOrigin[0]; const int scaleLog = nbBitsBaseline - targetLog; /* note : targetLog >= srcLog, hence scaleLog <= 1 */ const U32 minBits = nbBitsBaseline - maxWeight; int w; int const wEnd = (int)maxWeight + 1; /* Fill DTable in order of weight. */ for (w = 1; w < wEnd; ++w) { int const begin = (int)rankStart[w]; int const end = (int)rankStart[w+1]; U32 const nbBits = nbBitsBaseline - w; if (targetLog-nbBits >= minBits) { /* Enough room for a second symbol. */ int start = rankVal[w]; U32 const length = 1U << ((targetLog - nbBits) & 0x1F /* quiet static-analyzer */); int minWeight = nbBits + scaleLog; int s; if (minWeight < 1) minWeight = 1; /* Fill the DTable for every symbol of weight w. * These symbols get at least 1 second symbol. */ for (s = begin; s != end; ++s) { HUF_fillDTableX2Level2( DTable + start, targetLog, nbBits, rankValOrigin[nbBits], minWeight, wEnd, sortedList, rankStart, nbBitsBaseline, sortedList[s].symbol); start += length; } } else { /* Only a single symbol. */ HUF_fillDTableX2ForWeight( DTable + rankVal[w], sortedList + begin, sortedList + end, nbBits, targetLog, /* baseSeq */ 0, /* level */ 1); } } } typedef struct { rankValCol_t rankVal[HUF_TABLELOG_MAX]; U32 rankStats[HUF_TABLELOG_MAX + 1]; U32 rankStart0[HUF_TABLELOG_MAX + 3]; sortedSymbol_t sortedSymbol[HUF_SYMBOLVALUE_MAX + 1]; BYTE weightList[HUF_SYMBOLVALUE_MAX + 1]; U32 calleeWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32]; } HUF_ReadDTableX2_Workspace; size_t HUF_readDTableX2_wksp(HUF_DTable* DTable, const void* src, size_t srcSize, void* workSpace, size_t wkspSize, int flags) { U32 tableLog, maxW, nbSymbols; DTableDesc dtd = HUF_getDTableDesc(DTable); U32 maxTableLog = dtd.maxTableLog; size_t iSize; void* dtPtr = DTable+1; /* force compiler to avoid strict-aliasing */ HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr; U32 *rankStart; HUF_ReadDTableX2_Workspace* const wksp = (HUF_ReadDTableX2_Workspace*)workSpace; if (sizeof(*wksp) > wkspSize) return ERROR(GENERIC); rankStart = wksp->rankStart0 + 1; ZSTD_memset(wksp->rankStats, 0, sizeof(wksp->rankStats)); ZSTD_memset(wksp->rankStart0, 0, sizeof(wksp->rankStart0)); DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(HUF_DTable)); /* if compiler fails here, assertion is wrong */ if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge); /* ZSTD_memset(weightList, 0, sizeof(weightList)); */ /* is not necessary, even though some analyzer complain ... */ iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), flags); if (HUF_isError(iSize)) return iSize; /* check result */ if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge); /* DTable can't fit code depth */ if (tableLog <= HUF_DECODER_FAST_TABLELOG && maxTableLog > HUF_DECODER_FAST_TABLELOG) maxTableLog = HUF_DECODER_FAST_TABLELOG; /* find maxWeight */ for (maxW = tableLog; wksp->rankStats[maxW]==0; maxW--) {} /* necessarily finds a solution before 0 */ /* Get start index of each weight */ { U32 w, nextRankStart = 0; for (w=1; wrankStats[w]; rankStart[w] = curr; } rankStart[0] = nextRankStart; /* put all 0w symbols at the end of sorted list*/ rankStart[maxW+1] = nextRankStart; } /* sort symbols by weight */ { U32 s; for (s=0; sweightList[s]; U32 const r = rankStart[w]++; wksp->sortedSymbol[r].symbol = (BYTE)s; } rankStart[0] = 0; /* forget 0w symbols; this is beginning of weight(1) */ } /* Build rankVal */ { U32* const rankVal0 = wksp->rankVal[0]; { int const rescale = (maxTableLog-tableLog) - 1; /* tableLog <= maxTableLog */ U32 nextRankVal = 0; U32 w; for (w=1; wrankStats[w] << (w+rescale); rankVal0[w] = curr; } } { U32 const minBits = tableLog+1 - maxW; U32 consumed; for (consumed = minBits; consumed < maxTableLog - minBits + 1; consumed++) { U32* const rankValPtr = wksp->rankVal[consumed]; U32 w; for (w = 1; w < maxW+1; w++) { rankValPtr[w] = rankVal0[w] >> consumed; } } } } HUF_fillDTableX2(dt, maxTableLog, wksp->sortedSymbol, wksp->rankStart0, wksp->rankVal, maxW, tableLog+1); dtd.tableLog = (BYTE)maxTableLog; dtd.tableType = 1; ZSTD_memcpy(DTable, &dtd, sizeof(dtd)); return iSize; } FORCE_INLINE_TEMPLATE U32 HUF_decodeSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog) { size_t const val = BIT_lookBitsFast(DStream, dtLog); /* note : dtLog >= 1 */ ZSTD_memcpy(op, &dt[val].sequence, 2); BIT_skipBits(DStream, dt[val].nbBits); return dt[val].length; } FORCE_INLINE_TEMPLATE U32 HUF_decodeLastSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog) { size_t const val = BIT_lookBitsFast(DStream, dtLog); /* note : dtLog >= 1 */ ZSTD_memcpy(op, &dt[val].sequence, 1); if (dt[val].length==1) { BIT_skipBits(DStream, dt[val].nbBits); } else { if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) { BIT_skipBits(DStream, dt[val].nbBits); if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8)) /* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */ DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8); } } return 1; } #define HUF_DECODE_SYMBOLX2_0(ptr, DStreamPtr) \ ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog) #define HUF_DECODE_SYMBOLX2_1(ptr, DStreamPtr) \ if (MEM_64bits() || (HUF_TABLELOG_MAX<=12)) \ ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog) #define HUF_DECODE_SYMBOLX2_2(ptr, DStreamPtr) \ if (MEM_64bits()) \ ptr += HUF_decodeSymbolX2(ptr, DStreamPtr, dt, dtLog) HINT_INLINE size_t HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd, const HUF_DEltX2* const dt, const U32 dtLog) { BYTE* const pStart = p; /* up to 8 symbols at a time */ if ((size_t)(pEnd - p) >= sizeof(bitDPtr->bitContainer)) { if (dtLog <= 11 && MEM_64bits()) { /* up to 10 symbols at a time */ while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-9)) { HUF_DECODE_SYMBOLX2_0(p, bitDPtr); HUF_DECODE_SYMBOLX2_0(p, bitDPtr); HUF_DECODE_SYMBOLX2_0(p, bitDPtr); HUF_DECODE_SYMBOLX2_0(p, bitDPtr); HUF_DECODE_SYMBOLX2_0(p, bitDPtr); } } else { /* up to 8 symbols at a time */ while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) { HUF_DECODE_SYMBOLX2_2(p, bitDPtr); HUF_DECODE_SYMBOLX2_1(p, bitDPtr); HUF_DECODE_SYMBOLX2_2(p, bitDPtr); HUF_DECODE_SYMBOLX2_0(p, bitDPtr); } } } else { BIT_reloadDStream(bitDPtr); } /* closer to end : up to 2 symbols at a time */ if ((size_t)(pEnd - p) >= 2) { while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p <= pEnd-2)) HUF_DECODE_SYMBOLX2_0(p, bitDPtr); while (p <= pEnd-2) HUF_DECODE_SYMBOLX2_0(p, bitDPtr); /* no need to reload : reached the end of DStream */ } if (p < pEnd) p += HUF_decodeLastSymbolX2(p, bitDPtr, dt, dtLog); return p-pStart; } FORCE_INLINE_TEMPLATE size_t HUF_decompress1X2_usingDTable_internal_body( void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable) { BIT_DStream_t bitD; /* Init */ CHECK_F( BIT_initDStream(&bitD, cSrc, cSrcSize) ); /* decode */ { BYTE* const ostart = (BYTE*) dst; BYTE* const oend = ostart + dstSize; const void* const dtPtr = DTable+1; /* force compiler to not use strict-aliasing */ const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr; DTableDesc const dtd = HUF_getDTableDesc(DTable); HUF_decodeStreamX2(ostart, &bitD, oend, dt, dtd.tableLog); } /* check */ if (!BIT_endOfDStream(&bitD)) return ERROR(corruption_detected); /* decoded size */ return dstSize; } /* HUF_decompress4X2_usingDTable_internal_body(): * Conditions: * @dstSize >= 6 */ FORCE_INLINE_TEMPLATE size_t HUF_decompress4X2_usingDTable_internal_body( void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable) { if (cSrcSize < 10) return ERROR(corruption_detected); /* strict minimum : jump table + 1 byte per stream */ { const BYTE* const istart = (const BYTE*) cSrc; BYTE* const ostart = (BYTE*) dst; BYTE* const oend = ostart + dstSize; BYTE* const olimit = oend - (sizeof(size_t)-1); const void* const dtPtr = DTable+1; const HUF_DEltX2* const dt = (const HUF_DEltX2*)dtPtr; /* Init */ BIT_DStream_t bitD1; BIT_DStream_t bitD2; BIT_DStream_t bitD3; BIT_DStream_t bitD4; size_t const length1 = MEM_readLE16(istart); size_t const length2 = MEM_readLE16(istart+2); size_t const length3 = MEM_readLE16(istart+4); size_t const length4 = cSrcSize - (length1 + length2 + length3 + 6); const BYTE* const istart1 = istart + 6; /* jumpTable */ const BYTE* const istart2 = istart1 + length1; const BYTE* const istart3 = istart2 + length2; const BYTE* const istart4 = istart3 + length3; size_t const segmentSize = (dstSize+3) / 4; BYTE* const opStart2 = ostart + segmentSize; BYTE* const opStart3 = opStart2 + segmentSize; BYTE* const opStart4 = opStart3 + segmentSize; BYTE* op1 = ostart; BYTE* op2 = opStart2; BYTE* op3 = opStart3; BYTE* op4 = opStart4; U32 endSignal = 1; DTableDesc const dtd = HUF_getDTableDesc(DTable); U32 const dtLog = dtd.tableLog; if (length4 > cSrcSize) return ERROR(corruption_detected); /* overflow */ if (opStart4 > oend) return ERROR(corruption_detected); /* overflow */ if (dstSize < 6) return ERROR(corruption_detected); /* stream 4-split doesn't work */ CHECK_F( BIT_initDStream(&bitD1, istart1, length1) ); CHECK_F( BIT_initDStream(&bitD2, istart2, length2) ); CHECK_F( BIT_initDStream(&bitD3, istart3, length3) ); CHECK_F( BIT_initDStream(&bitD4, istart4, length4) ); /* 16-32 symbols per loop (4-8 symbols per stream) */ if ((size_t)(oend - op4) >= sizeof(size_t)) { for ( ; (endSignal) & (op4 < olimit); ) { #if defined(__clang__) && (defined(__x86_64__) || defined(__i386__)) HUF_DECODE_SYMBOLX2_2(op1, &bitD1); HUF_DECODE_SYMBOLX2_1(op1, &bitD1); HUF_DECODE_SYMBOLX2_2(op1, &bitD1); HUF_DECODE_SYMBOLX2_0(op1, &bitD1); HUF_DECODE_SYMBOLX2_2(op2, &bitD2); HUF_DECODE_SYMBOLX2_1(op2, &bitD2); HUF_DECODE_SYMBOLX2_2(op2, &bitD2); HUF_DECODE_SYMBOLX2_0(op2, &bitD2); endSignal &= BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished; endSignal &= BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished; HUF_DECODE_SYMBOLX2_2(op3, &bitD3); HUF_DECODE_SYMBOLX2_1(op3, &bitD3); HUF_DECODE_SYMBOLX2_2(op3, &bitD3); HUF_DECODE_SYMBOLX2_0(op3, &bitD3); HUF_DECODE_SYMBOLX2_2(op4, &bitD4); HUF_DECODE_SYMBOLX2_1(op4, &bitD4); HUF_DECODE_SYMBOLX2_2(op4, &bitD4); HUF_DECODE_SYMBOLX2_0(op4, &bitD4); endSignal &= BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished; endSignal &= BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished; #else HUF_DECODE_SYMBOLX2_2(op1, &bitD1); HUF_DECODE_SYMBOLX2_2(op2, &bitD2); HUF_DECODE_SYMBOLX2_2(op3, &bitD3); HUF_DECODE_SYMBOLX2_2(op4, &bitD4); HUF_DECODE_SYMBOLX2_1(op1, &bitD1); HUF_DECODE_SYMBOLX2_1(op2, &bitD2); HUF_DECODE_SYMBOLX2_1(op3, &bitD3); HUF_DECODE_SYMBOLX2_1(op4, &bitD4); HUF_DECODE_SYMBOLX2_2(op1, &bitD1); HUF_DECODE_SYMBOLX2_2(op2, &bitD2); HUF_DECODE_SYMBOLX2_2(op3, &bitD3); HUF_DECODE_SYMBOLX2_2(op4, &bitD4); HUF_DECODE_SYMBOLX2_0(op1, &bitD1); HUF_DECODE_SYMBOLX2_0(op2, &bitD2); HUF_DECODE_SYMBOLX2_0(op3, &bitD3); HUF_DECODE_SYMBOLX2_0(op4, &bitD4); endSignal = (U32)LIKELY((U32) (BIT_reloadDStreamFast(&bitD1) == BIT_DStream_unfinished) & (BIT_reloadDStreamFast(&bitD2) == BIT_DStream_unfinished) & (BIT_reloadDStreamFast(&bitD3) == BIT_DStream_unfinished) & (BIT_reloadDStreamFast(&bitD4) == BIT_DStream_unfinished)); #endif } } /* check corruption */ if (op1 > opStart2) return ERROR(corruption_detected); if (op2 > opStart3) return ERROR(corruption_detected); if (op3 > opStart4) return ERROR(corruption_detected); /* note : op4 already verified within main loop */ /* finish bitStreams one by one */ HUF_decodeStreamX2(op1, &bitD1, opStart2, dt, dtLog); HUF_decodeStreamX2(op2, &bitD2, opStart3, dt, dtLog); HUF_decodeStreamX2(op3, &bitD3, opStart4, dt, dtLog); HUF_decodeStreamX2(op4, &bitD4, oend, dt, dtLog); /* check */ { U32 const endCheck = BIT_endOfDStream(&bitD1) & BIT_endOfDStream(&bitD2) & BIT_endOfDStream(&bitD3) & BIT_endOfDStream(&bitD4); if (!endCheck) return ERROR(corruption_detected); } /* decoded size */ return dstSize; } } #if HUF_NEED_BMI2_FUNCTION static BMI2_TARGET_ATTRIBUTE size_t HUF_decompress4X2_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc, size_t cSrcSize, HUF_DTable const* DTable) { return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); } #endif static size_t HUF_decompress4X2_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc, size_t cSrcSize, HUF_DTable const* DTable) { return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable); } #if ZSTD_ENABLE_ASM_X86_64_BMI2 HUF_ASM_DECL void HUF_decompress4X2_usingDTable_internal_fast_asm_loop(HUF_DecompressFastArgs* args) ZSTDLIB_HIDDEN; #endif static HUF_FAST_BMI2_ATTRS void HUF_decompress4X2_usingDTable_internal_fast_c_loop(HUF_DecompressFastArgs* args) { U64 bits[4]; BYTE const* ip[4]; BYTE* op[4]; BYTE* oend[4]; HUF_DEltX2 const* const dtable = (HUF_DEltX2 const*)args->dt; BYTE const* const ilimit = args->ilimit; /* Copy the arguments to local registers. */ ZSTD_memcpy(&bits, &args->bits, sizeof(bits)); ZSTD_memcpy(&ip, &args->ip, sizeof(ip)); ZSTD_memcpy(&op, &args->op, sizeof(op)); oend[0] = op[1]; oend[1] = op[2]; oend[2] = op[3]; oend[3] = args->oend; assert(MEM_isLittleEndian()); assert(!MEM_32bits()); for (;;) { BYTE* olimit; int stream; int symbol; /* Assert loop preconditions */ #ifndef NDEBUG for (stream = 0; stream < 4; ++stream) { assert(op[stream] <= oend[stream]); assert(ip[stream] >= ilimit); } #endif /* Compute olimit */ { /* Each loop does 5 table lookups for each of the 4 streams. * Each table lookup consumes up to 11 bits of input, and produces * up to 2 bytes of output. */ /* We can consume up to 7 bytes of input per iteration per stream. * We also know that each input pointer is >= ip[0]. So we can run * iters loops before running out of input. */ size_t iters = (size_t)(ip[0] - ilimit) / 7; /* Each iteration can produce up to 10 bytes of output per stream. * Each output stream my advance at different rates. So take the * minimum number of safe iterations among all the output streams. */ for (stream = 0; stream < 4; ++stream) { size_t const oiters = (size_t)(oend[stream] - op[stream]) / 10; iters = MIN(iters, oiters); } /* Each iteration produces at least 5 output symbols. So until * op[3] crosses olimit, we know we haven't executed iters * iterations yet. This saves us maintaining an iters counter, * at the expense of computing the remaining # of iterations * more frequently. */ olimit = op[3] + (iters * 5); /* Exit the fast decoding loop if we are too close to the end. */ if (op[3] + 10 > olimit) break; /* Exit the decoding loop if any input pointer has crossed the * previous one. This indicates corruption, and a precondition * to our loop is that ip[i] >= ip[0]. */ for (stream = 1; stream < 4; ++stream) { if (ip[stream] < ip[stream - 1]) goto _out; } } #ifndef NDEBUG for (stream = 1; stream < 4; ++stream) { assert(ip[stream] >= ip[stream - 1]); } #endif do { /* Do 5 table lookups for each of the first 3 streams */ for (symbol = 0; symbol < 5; ++symbol) { for (stream = 0; stream < 3; ++stream) { int const index = (int)(bits[stream] >> 53); HUF_DEltX2 const entry = dtable[index]; MEM_write16(op[stream], entry.sequence); bits[stream] <<= (entry.nbBits); op[stream] += (entry.length); } } /* Do 1 table lookup from the final stream */ { int const index = (int)(bits[3] >> 53); HUF_DEltX2 const entry = dtable[index]; MEM_write16(op[3], entry.sequence); bits[3] <<= (entry.nbBits); op[3] += (entry.length); } /* Do 4 table lookups from the final stream & reload bitstreams */ for (stream = 0; stream < 4; ++stream) { /* Do a table lookup from the final stream. * This is interleaved with the reloading to reduce register * pressure. This shouldn't be necessary, but compilers can * struggle with codegen with high register pressure. */ { int const index = (int)(bits[3] >> 53); HUF_DEltX2 const entry = dtable[index]; MEM_write16(op[3], entry.sequence); bits[3] <<= (entry.nbBits); op[3] += (entry.length); } /* Reload the bistreams. The final bitstream must be reloaded * after the 5th symbol was decoded. */ { int const ctz = ZSTD_countTrailingZeros64(bits[stream]); int const nbBits = ctz & 7; int const nbBytes = ctz >> 3; ip[stream] -= nbBytes; bits[stream] = MEM_read64(ip[stream]) | 1; bits[stream] <<= nbBits; } } } while (op[3] < olimit); } _out: /* Save the final values of each of the state variables back to args. */ ZSTD_memcpy(&args->bits, &bits, sizeof(bits)); ZSTD_memcpy(&args->ip, &ip, sizeof(ip)); ZSTD_memcpy(&args->op, &op, sizeof(op)); } static HUF_FAST_BMI2_ATTRS size_t HUF_decompress4X2_usingDTable_internal_fast( void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, HUF_DecompressFastLoopFn loopFn) { void const* dt = DTable + 1; const BYTE* const iend = (const BYTE*)cSrc + 6; BYTE* const oend = (BYTE*)dst + dstSize; HUF_DecompressFastArgs args; { size_t const ret = HUF_DecompressFastArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable); FORWARD_IF_ERROR(ret, "Failed to init asm args"); if (ret == 0) return 0; } assert(args.ip[0] >= args.ilimit); loopFn(&args); /* note : op4 already verified within main loop */ assert(args.ip[0] >= iend); assert(args.ip[1] >= iend); assert(args.ip[2] >= iend); assert(args.ip[3] >= iend); assert(args.op[3] <= oend); (void)iend; /* finish bitStreams one by one */ { size_t const segmentSize = (dstSize+3) / 4; BYTE* segmentEnd = (BYTE*)dst; int i; for (i = 0; i < 4; ++i) { BIT_DStream_t bit; if (segmentSize <= (size_t)(oend - segmentEnd)) segmentEnd += segmentSize; else segmentEnd = oend; FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption"); args.op[i] += HUF_decodeStreamX2(args.op[i], &bit, segmentEnd, (HUF_DEltX2 const*)dt, HUF_DECODER_FAST_TABLELOG); if (args.op[i] != segmentEnd) return ERROR(corruption_detected); } } /* decoded size */ return dstSize; } static size_t HUF_decompress4X2_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc, size_t cSrcSize, HUF_DTable const* DTable, int flags) { HUF_DecompressUsingDTableFn fallbackFn = HUF_decompress4X2_usingDTable_internal_default; HUF_DecompressFastLoopFn loopFn = HUF_decompress4X2_usingDTable_internal_fast_c_loop; #if DYNAMIC_BMI2 if (flags & HUF_flags_bmi2) { fallbackFn = HUF_decompress4X2_usingDTable_internal_bmi2; # if ZSTD_ENABLE_ASM_X86_64_BMI2 if (!(flags & HUF_flags_disableAsm)) { loopFn = HUF_decompress4X2_usingDTable_internal_fast_asm_loop; } # endif } else { return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); } #endif #if ZSTD_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__) if (!(flags & HUF_flags_disableAsm)) { loopFn = HUF_decompress4X2_usingDTable_internal_fast_asm_loop; } #endif if (!(flags & HUF_flags_disableFast)) { size_t const ret = HUF_decompress4X2_usingDTable_internal_fast(dst, dstSize, cSrc, cSrcSize, DTable, loopFn); if (ret != 0) return ret; } return fallbackFn(dst, dstSize, cSrc, cSrcSize, DTable); } HUF_DGEN(HUF_decompress1X2_usingDTable_internal) size_t HUF_decompress1X2_DCtx_wksp(HUF_DTable* DCtx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) { const BYTE* ip = (const BYTE*) cSrc; size_t const hSize = HUF_readDTableX2_wksp(DCtx, cSrc, cSrcSize, workSpace, wkspSize, flags); if (HUF_isError(hSize)) return hSize; if (hSize >= cSrcSize) return ERROR(srcSize_wrong); ip += hSize; cSrcSize -= hSize; return HUF_decompress1X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, DCtx, flags); } static size_t HUF_decompress4X2_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) { const BYTE* ip = (const BYTE*) cSrc; size_t hSize = HUF_readDTableX2_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags); if (HUF_isError(hSize)) return hSize; if (hSize >= cSrcSize) return ERROR(srcSize_wrong); ip += hSize; cSrcSize -= hSize; return HUF_decompress4X2_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags); } #endif /* HUF_FORCE_DECOMPRESS_X1 */ /* ***********************************/ /* Universal decompression selectors */ /* ***********************************/ #if !defined(HUF_FORCE_DECOMPRESS_X1) && !defined(HUF_FORCE_DECOMPRESS_X2) typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t; static const algo_time_t algoTime[16 /* Quantization */][2 /* single, double */] = { /* single, double, quad */ {{0,0}, {1,1}}, /* Q==0 : impossible */ {{0,0}, {1,1}}, /* Q==1 : impossible */ {{ 150,216}, { 381,119}}, /* Q == 2 : 12-18% */ {{ 170,205}, { 514,112}}, /* Q == 3 : 18-25% */ {{ 177,199}, { 539,110}}, /* Q == 4 : 25-32% */ {{ 197,194}, { 644,107}}, /* Q == 5 : 32-38% */ {{ 221,192}, { 735,107}}, /* Q == 6 : 38-44% */ {{ 256,189}, { 881,106}}, /* Q == 7 : 44-50% */ {{ 359,188}, {1167,109}}, /* Q == 8 : 50-56% */ {{ 582,187}, {1570,114}}, /* Q == 9 : 56-62% */ {{ 688,187}, {1712,122}}, /* Q ==10 : 62-69% */ {{ 825,186}, {1965,136}}, /* Q ==11 : 69-75% */ {{ 976,185}, {2131,150}}, /* Q ==12 : 75-81% */ {{1180,186}, {2070,175}}, /* Q ==13 : 81-87% */ {{1377,185}, {1731,202}}, /* Q ==14 : 87-93% */ {{1412,185}, {1695,202}}, /* Q ==15 : 93-99% */ }; #endif /** HUF_selectDecoder() : * Tells which decoder is likely to decode faster, * based on a set of pre-computed metrics. * @return : 0==HUF_decompress4X1, 1==HUF_decompress4X2 . * Assumption : 0 < dstSize <= 128 KB */ U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize) { assert(dstSize > 0); assert(dstSize <= 128*1024); #if defined(HUF_FORCE_DECOMPRESS_X1) (void)dstSize; (void)cSrcSize; return 0; #elif defined(HUF_FORCE_DECOMPRESS_X2) (void)dstSize; (void)cSrcSize; return 1; #else /* decoder timing evaluation */ { U32 const Q = (cSrcSize >= dstSize) ? 15 : (U32)(cSrcSize * 16 / dstSize); /* Q < 16 */ U32 const D256 = (U32)(dstSize >> 8); U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256); U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256); DTime1 += DTime1 >> 5; /* small advantage to algorithm using less memory, to reduce cache eviction */ return DTime1 < DTime0; } #endif } size_t HUF_decompress1X_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) { /* validation checks */ if (dstSize == 0) return ERROR(dstSize_tooSmall); if (cSrcSize > dstSize) return ERROR(corruption_detected); /* invalid */ if (cSrcSize == dstSize) { ZSTD_memcpy(dst, cSrc, dstSize); return dstSize; } /* not compressed */ if (cSrcSize == 1) { ZSTD_memset(dst, *(const BYTE*)cSrc, dstSize); return dstSize; } /* RLE */ { U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize); #if defined(HUF_FORCE_DECOMPRESS_X1) (void)algoNb; assert(algoNb == 0); return HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); #elif defined(HUF_FORCE_DECOMPRESS_X2) (void)algoNb; assert(algoNb == 1); return HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); #else return algoNb ? HUF_decompress1X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags): HUF_decompress1X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); #endif } } size_t HUF_decompress1X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags) { DTableDesc const dtd = HUF_getDTableDesc(DTable); #if defined(HUF_FORCE_DECOMPRESS_X1) (void)dtd; assert(dtd.tableType == 0); return HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); #elif defined(HUF_FORCE_DECOMPRESS_X2) (void)dtd; assert(dtd.tableType == 1); return HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); #else return dtd.tableType ? HUF_decompress1X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags) : HUF_decompress1X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); #endif } #ifndef HUF_FORCE_DECOMPRESS_X2 size_t HUF_decompress1X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) { const BYTE* ip = (const BYTE*) cSrc; size_t const hSize = HUF_readDTableX1_wksp(dctx, cSrc, cSrcSize, workSpace, wkspSize, flags); if (HUF_isError(hSize)) return hSize; if (hSize >= cSrcSize) return ERROR(srcSize_wrong); ip += hSize; cSrcSize -= hSize; return HUF_decompress1X1_usingDTable_internal(dst, dstSize, ip, cSrcSize, dctx, flags); } #endif size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize, const void* cSrc, size_t cSrcSize, const HUF_DTable* DTable, int flags) { DTableDesc const dtd = HUF_getDTableDesc(DTable); #if defined(HUF_FORCE_DECOMPRESS_X1) (void)dtd; assert(dtd.tableType == 0); return HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); #elif defined(HUF_FORCE_DECOMPRESS_X2) (void)dtd; assert(dtd.tableType == 1); return HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); #else return dtd.tableType ? HUF_decompress4X2_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags) : HUF_decompress4X1_usingDTable_internal(dst, maxDstSize, cSrc, cSrcSize, DTable, flags); #endif } size_t HUF_decompress4X_hufOnly_wksp(HUF_DTable* dctx, void* dst, size_t dstSize, const void* cSrc, size_t cSrcSize, void* workSpace, size_t wkspSize, int flags) { /* validation checks */ if (dstSize == 0) return ERROR(dstSize_tooSmall); if (cSrcSize == 0) return ERROR(corruption_detected); { U32 const algoNb = HUF_selectDecoder(dstSize, cSrcSize); #if defined(HUF_FORCE_DECOMPRESS_X1) (void)algoNb; assert(algoNb == 0); return HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); #elif defined(HUF_FORCE_DECOMPRESS_X2) (void)algoNb; assert(algoNb == 1); return HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); #else return algoNb ? HUF_decompress4X2_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags) : HUF_decompress4X1_DCtx_wksp(dctx, dst, dstSize, cSrc, cSrcSize, workSpace, wkspSize, flags); #endif } }