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Yann Collet 2015-11-06 18:44:54 +01:00
parent 9b8e453713
commit 628065cf98
1 changed files with 9 additions and 16 deletions
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25
lib/zstdhc.c
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@ -655,7 +655,6 @@ size_t ZSTD_HC_compressBlock_lazy_generic(ZSTD_HC_CCtx* ctx,
/* let's try to find a better solution */ /* let's try to find a better solution */
start = ip; start = ip;
while ((start>anchor) && (start-offset>ctx->base) && (start[-1] == start[-1-offset])) { start--; matchLength++; } /* catch up */
while (ip<ilimit) while (ip<ilimit)
{ {
@ -671,15 +670,11 @@ size_t ZSTD_HC_compressBlock_lazy_generic(ZSTD_HC_CCtx* ctx,
{ {
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);
const BYTE* start2 = ip; int gain2 = (int)(ml2*(3+deep) - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1, gain2; int gain1 = (int)(matchLength*(3+deep) - ZSTD_highbit((U32)offset+1) + (3+deep));
if (ml2)
while ((start2>anchor) && (start2-offset2>ctx->base) && (start2[-1] == start2[-1-offset2])) { start2--; ml2++; } /* catch up */
gain2 = (int)(ml2*(3+deep) - ZSTD_highbit((U32)offset2+1)); /* raw approx */
gain1 = (int)(matchLength*(3+deep) - ZSTD_highbit((U32)offset+1) + (3+deep));
if (gain2 > gain1) if (gain2 > gain1)
{ {
matchLength = ml2, offset = offset2, start = start2; matchLength = ml2, offset = offset2, start = ip;
continue; /* search a better one */ continue; /* search a better one */
} }
} }
@ -699,16 +694,12 @@ size_t ZSTD_HC_compressBlock_lazy_generic(ZSTD_HC_CCtx* ctx,
{ {
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);
const BYTE* start2 = ip; int gain2 = (int)(ml2*4 - ZSTD_highbit((U32)offset2+1)); /* raw approx */
int gain1, gain2; int gain1 = (int)(matchLength*4 - ZSTD_highbit((U32)offset+1) + 7);
if (ml2)
while ((start2>anchor) && (start2-offset2>ctx->base) && (start2[-1] == start2[-1-offset2])) { start2--; ml2++; } /* catch up */
gain2 = (int)(ml2*(3+deep) - ZSTD_highbit((U32)offset2+1)); /* raw approx */
gain1 = (int)(matchLength*(3+deep) - ZSTD_highbit((U32)offset+1) + (3+deep));
if (gain2 > gain1) if (gain2 > gain1)
{ {
matchLength = ml2, offset = offset2, start = start2; matchLength = ml2, offset = offset2, start = ip;
continue; /* search a better one */ continue;
} }
} }
} }
@ -716,6 +707,8 @@ size_t ZSTD_HC_compressBlock_lazy_generic(ZSTD_HC_CCtx* ctx,
} }
/* store sequence */ /* store sequence */
if (offset)
while ((start>anchor) && (start-offset>ctx->base) && (start[-1] == start[-1-offset])) { start--; matchLength++; } /* catch up */
{ {
size_t litLength = start - anchor; size_t litLength = start - anchor;
if (offset) offset_1 = offset; if (offset) offset_1 = offset;