krak/zstd
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Code Issues Releases 1 Activity

Changed allocation strategy to reduce stack usage of ZSTD_compressSequences()

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This commit is contained in:
Yann Collet 2015-07-07 16:54:25 -08:00
parent 858db1291f
commit 968f275981
1 changed files with 11 additions and 8 deletions
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19
lib/zstd.c
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@ -146,7 +146,7 @@ static const U32 g_maxDistance = 4 * BLOCKSIZE;
static const U32 g_maxLimit = 1 GB;
static const U32 g_searchStrength = 8;
#define WORKPLACESIZE (BLOCKSIZE*11/4)
#define WORKPLACESIZE (BLOCKSIZE*3)
#define MINMATCH 4
#define MLbits 7
#define LLbits 6
@ -292,6 +292,8 @@ typedef struct {
void* buffer;
U32* offsetStart;
U32* offset;
BYTE* offCodeStart;
BYTE* offCode;
BYTE* litStart;
BYTE* lit;
BYTE* litLengthStart;
@ -332,7 +334,8 @@ ZSTD_Cctx* ZSTD_createCCtx(void)
if (ctx==NULL) return NULL;
ctx->seqStore.buffer = malloc(WORKPLACESIZE);
ctx->seqStore.offsetStart = (U32*) (ctx->seqStore.buffer);
ctx->seqStore.litStart = (BYTE*) (ctx->seqStore.offsetStart + (BLOCKSIZE>>2));
ctx->seqStore.offCodeStart = (BYTE*) (ctx->seqStore.offsetStart + (BLOCKSIZE>>2));
ctx->seqStore.litStart = ctx->seqStore.offCodeStart + (BLOCKSIZE>>2);
ctx->seqStore.litLengthStart = ctx->seqStore.litStart + BLOCKSIZE;
ctx->seqStore.matchLengthStart = ctx->seqStore.litLengthStart + (BLOCKSIZE>>2);
ctx->seqStore.dumpsStart = ctx->seqStore.matchLengthStart + (BLOCKSIZE>>2);
@ -680,7 +683,7 @@ static size_t ZSTD_compressSequences(BYTE* dst, size_t maxDstSize,
const BYTE* op_matchLength = seqStorePtr->matchLength;
const size_t nbSeq = op_litLength - op_litLength_start;
BYTE* op;
BYTE offsetBits_start[BLOCKSIZE / 4];
BYTE* offsetBits_start = seqStorePtr->offCodeStart;
BYTE* offsetBitsPtr = offsetBits_start;
const size_t minGain = ZSTD_minGain(srcSize);
const size_t maxCSize = srcSize - minGain;
@ -1010,13 +1013,12 @@ size_t ZSTD_compressBegin(ZSTD_Cctx* ctx, void* dst, size_t maxDstSize)
}
/* this should be auto-vectorized by compiler */
static void ZSTD_scaleDownCtx(void* cctx, const U32 limit)
{
cctxi_t* ctx = (cctxi_t*) cctx;
int i;
#if defined(__AVX2__) /* <immintrin.h> */
#if defined(__AVX2__)
/* AVX2 version */
__m256i* h = ctx->hashTable;
const __m256i limit8 = _mm256_set1_epi32(limit);
@ -1028,6 +1030,7 @@ static void ZSTD_scaleDownCtx(void* cctx, const U32 limit)
_mm256_storeu_si256((__m256i*)(h+i), src);
}
#else
/* this should be auto-vectorized by compiler */
U32* h = ctx->hashTable;
for (i=0; i<HASH_TABLESIZE; ++i)
{
@ -1039,7 +1042,6 @@ static void ZSTD_scaleDownCtx(void* cctx, const U32 limit)
}
/* this should be auto-vectorized by compiler */
static void ZSTD_limitCtx(void* cctx, const U32 limit)
{
cctxi_t* ctx = (cctxi_t*) cctx;
@ -1054,7 +1056,7 @@ static void ZSTD_limitCtx(void* cctx, const U32 limit)
return;
}
#if defined(__AVX2__) /* <immintrin.h> */
#if defined(__AVX2__)
/* AVX2 version */
{
__m256i* h = ctx->hashTable;
@ -1068,6 +1070,7 @@ static void ZSTD_limitCtx(void* cctx, const U32 limit)
}
}
#else
/* this should be auto-vectorized by compiler */
{
U32* h = (U32*)(ctx->hashTable);
for (i=0; i<HASH_TABLESIZE; ++i)
@ -1089,7 +1092,7 @@ size_t ZSTD_compressContinue(ZSTD_Cctx* cctx, void* dst, size_t maxDstSize, con
const U32 updateRate = 2 * BLOCKSIZE;
/* Init */
if (maxDstSize < ZSTD_compressBound(srcSize) - 4 /*header size*/) return (size_t)-ZSTD_ERROR_maxDstSize_tooSmall;
if (maxDstSize < ZSTD_compressBound(srcSize) - 4 /* frame header size*/) return (size_t)-ZSTD_ERROR_maxDstSize_tooSmall;
if (ctx->base==NULL)
ctx->base = (const BYTE*)src, ctx->current=0, ctx->nextUpdate = g_maxDistance;
if (src != ctx->base + ctx->current) /* not contiguous */