From: Nick Terrell Date: Fri, 5 Mar 2021 20:36:50 +0000 (-0800) Subject: [huf] Reduce stack usage of HUF_readDTableX2 by ~460 bytes X-Git-Tag: v1.4.10~18^2~3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0f18059a4ed9dadb9c7bb837d9b9664da786f553;p=thirdparty%2Fzstd.git [huf] Reduce stack usage of HUF_readDTableX2 by ~460 bytes * Use `HUF_readStats_wksp()` * Use workspace in `HUF_fillDTableX2*()` * Clean up workspace usage to use a workspace struct --- diff --git a/lib/decompress/huf_decompress.c b/lib/decompress/huf_decompress.c index 7699c9203..4481484f7 100644 --- a/lib/decompress/huf_decompress.c +++ b/lib/decompress/huf_decompress.c @@ -528,13 +528,15 @@ typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX]; static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 consumed, const U32* rankValOrigin, const int minWeight, const sortedSymbol_t* sortedSymbols, const U32 sortedListSize, - U32 nbBitsBaseline, U16 baseSeq) + U32 nbBitsBaseline, U16 baseSeq, U32* wksp, size_t wkspSize) { HUF_DEltX2 DElt; - U32 rankVal[HUF_TABLELOG_MAX + 1]; + U32* rankVal = wksp; + assert(wkspSize >= HUF_TABLELOG_MAX + 1); + (void)wkspSize; /* get pre-calculated rankVal */ - ZSTD_memcpy(rankVal, rankValOrigin, sizeof(rankVal)); + ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1)); /* fill skipped values */ if (minWeight>1) { @@ -569,14 +571,18 @@ static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 co static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog, const sortedSymbol_t* sortedList, const U32 sortedListSize, const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight, - const U32 nbBitsBaseline) + const U32 nbBitsBaseline, U32* wksp, size_t wkspSize) { - U32 rankVal[HUF_TABLELOG_MAX + 1]; + U32* rankVal = wksp; const int scaleLog = nbBitsBaseline - targetLog; /* note : targetLog >= srcLog, hence scaleLog <= 1 */ const U32 minBits = nbBitsBaseline - maxWeight; U32 s; - ZSTD_memcpy(rankVal, rankValOrigin, sizeof(rankVal)); + assert(wkspSize >= HUF_TABLELOG_MAX + 1); + wksp += HUF_TABLELOG_MAX + 1; + wkspSize -= HUF_TABLELOG_MAX + 1; + + ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1)); /* fill DTable */ for (s=0; s> 2; - rankStats = (U32 *)workSpace + spaceUsed32; - spaceUsed32 += HUF_TABLELOG_MAX + 1; - rankStart0 = (U32 *)workSpace + spaceUsed32; - spaceUsed32 += HUF_TABLELOG_MAX + 2; - sortedSymbol = (sortedSymbol_t *)workSpace + (spaceUsed32 * sizeof(U32)) / sizeof(sortedSymbol_t); - spaceUsed32 += HUF_ALIGN(sizeof(sortedSymbol_t) * (HUF_SYMBOLVALUE_MAX + 1), sizeof(U32)) >> 2; - weightList = (BYTE *)((U32 *)workSpace + spaceUsed32); - spaceUsed32 += HUF_ALIGN(HUF_SYMBOLVALUE_MAX + 1, sizeof(U32)) >> 2; - - if ((spaceUsed32 << 2) > wkspSize) return ERROR(tableLog_tooLarge); - - rankStart = rankStart0 + 1; - ZSTD_memset(rankStats, 0, sizeof(U32) * (2 * HUF_TABLELOG_MAX + 2 + 1)); + HUF_ReadDTableX2_Workspace* wksp = (HUF_ReadDTableX2_Workspace*)workSpace; + + if (sizeof(*wksp) > wkspSize) return ERROR(tableLog_tooLarge); + + 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(weightList, HUF_SYMBOLVALUE_MAX + 1, rankStats, &nbSymbols, &tableLog, src, srcSize); + iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->wksp, sizeof(wksp->wksp), /* bmi2 */ 0); if (HUF_isError(iSize)) return iSize; /* check result */ if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge); /* DTable can't fit code depth */ /* find maxWeight */ - for (maxW = tableLog; rankStats[maxW]==0; maxW--) {} /* necessarily finds a solution before 0 */ + 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*/ @@ -670,37 +670,38 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable, /* sort symbols by weight */ { U32 s; for (s=0; sweightList[s]; U32 const r = rankStart[w]++; - sortedSymbol[r].symbol = (BYTE)s; - sortedSymbol[r].weight = (BYTE)w; + wksp->sortedSymbol[r].symbol = (BYTE)s; + wksp->sortedSymbol[r].weight = (BYTE)w; } rankStart[0] = 0; /* forget 0w symbols; this is beginning of weight(1) */ } /* Build rankVal */ - { U32* const rankVal0 = rankVal[0]; + { 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 = rankVal[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, - sortedSymbol, sizeOfSort, - rankStart0, rankVal, maxW, - tableLog+1); + wksp->sortedSymbol, sizeOfSort, + wksp->rankStart0, wksp->rankVal, maxW, + tableLog+1, + wksp->wksp, sizeof(wksp->wksp) / sizeof(U32)); dtd.tableLog = (BYTE)maxTableLog; dtd.tableType = 1; @@ -1225,7 +1226,7 @@ size_t HUF_decompress1X1 (void* dst, size_t dstSize, const void* cSrc, size_t cS HUF_CREATE_STATIC_DTABLEX1(DTable, HUF_TABLELOG_MAX); return HUF_decompress1X1_DCtx (DTable, dst, dstSize, cSrc, cSrcSize); } -#endif +#endif #ifndef HUF_FORCE_DECOMPRESS_X1 size_t HUF_readDTableX2(HUF_DTable* DTable, const void* src, size_t srcSize)