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minor cr improvement

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This commit is contained in:
Yann Collet 2015-11-22 02:42:28 +01:00
parent 7a23179779
commit 007c1c6ff0
1 changed files with 11 additions and 10 deletions
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21
lib/zstd_compress.c
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@ -1282,7 +1282,7 @@ FORCE_INLINE size_t ZSTD_HcFindBestMatch_selectMLS (
FORCE_INLINE FORCE_INLINE
size_t ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx, size_t ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
void* dst, size_t maxDstSize, const void* src, size_t srcSize, void* dst, size_t maxDstSize, const void* src, size_t srcSize,
const U32 searchMethod, const U32 deep) /* 0 : hc; 1 : bt */ const U32 searchMethod, const U32 depth)
{ {
seqStore_t* seqStorePtr = &(ctx->seqStore); seqStore_t* seqStorePtr = &(ctx->seqStore);
const BYTE* const istart = (const BYTE*)src; const BYTE* const istart = (const BYTE*)src;
@ -1316,7 +1316,7 @@ size_t ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
{ {
/* repcode : we take it */ /* repcode : we take it */
matchLength = ZSTD_count(ip+1+MINMATCH, ip+1+MINMATCH-offset_1, iend) + MINMATCH; matchLength = ZSTD_count(ip+1+MINMATCH, ip+1+MINMATCH-offset_1, iend) + MINMATCH;
if (deep==0) goto _storeSequence; if (depth==0) goto _storeSequence;
} }
{ {
@ -1333,22 +1333,23 @@ size_t ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
} }
/* let's try to find a better solution */ /* let's try to find a better solution */
while ((deep>=1) && (ip<ilimit)) if (depth>=1)
while (ip<ilimit)
{ {
ip ++; ip ++;
if ((offset) && (MEM_read32(ip) == MEM_read32(ip - offset_1))) if ((offset) && (MEM_read32(ip) == MEM_read32(ip - offset_1)))
{ {
size_t ml2 = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH; size_t mlRep = ZSTD_count(ip+MINMATCH, ip+MINMATCH-offset_1, iend) + MINMATCH;
int gain2 = (int)(ml2 * 3); int gain2 = (int)(mlRep * 3);
int gain1 = (int)(matchLength*3 - ZSTD_highbit((U32)offset+1) + 1); int gain1 = (int)(matchLength*3 - ZSTD_highbit((U32)offset+1) + 1);
if ((ml2 >= MINMATCH) && (gain2 > gain1)) if ((mlRep >= MINMATCH) && (gain2 > gain1))
matchLength = ml2, offset = 0, start = ip; matchLength = mlRep, offset = 0, start = ip;
} }
{ {
size_t offset2=999999; size_t offset2=999999;
size_t ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls); size_t ml2 = searchMax(ctx, ip, iend, &offset2, maxSearches, mls);
int gain2 = (int)(ml2*(3+deep) - ZSTD_highbit((U32)offset2+1)); /* raw approx */ int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1 = (int)(matchLength*(3+deep) - ZSTD_highbit((U32)offset+1) + (3+deep)); int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 4);
if ((ml2 >= MINMATCH) && (gain2 > gain1)) if ((ml2 >= MINMATCH) && (gain2 > gain1))
{ {
matchLength = ml2, offset = offset2, start = ip; matchLength = ml2, offset = offset2, start = ip;
@ -1357,7 +1358,7 @@ size_t ZSTD_compressBlock_lazy_generic(ZSTD_CCtx* ctx,
} }
/* let's find an even better one */ /* let's find an even better one */
if ((deep==2) && (ip<ilimit)) if ((depth==2) && (ip<ilimit))
{ {
ip ++; ip ++;
if ((offset) && (MEM_read32(ip) == MEM_read32(ip - offset_1))) if ((offset) && (MEM_read32(ip) == MEM_read32(ip - offset_1)))