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minor fast mode improvement

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This commit is contained in:
Yann Collet 2016-01-02 01:16:28 +01:00
parent 2cc12cb3cb
commit 96ffa424eb
1 changed files with 3 additions and 2 deletions
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5
lib/zstd_compress.c
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@ -787,7 +787,8 @@ size_t ZSTD_compressBlock_fast_generic(ZSTD_CCtx* zc,
const size_t h = ZSTD_hashPtr(ip, hBits, mls); const size_t h = ZSTD_hashPtr(ip, hBits, mls);
const U32 matchIndex = hashTable[h]; const U32 matchIndex = hashTable[h];
const BYTE* match = base + matchIndex; const BYTE* match = base + matchIndex;
hashTable[h] = (U32)(ip-base); const U32 current = (U32)(ip-base);
hashTable[h] = current; /* update hash table */
if (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)) /* note : by construction, offset_1 <= (ip-base) */ if (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)) /* note : by construction, offset_1 <= (ip-base) */
{ {
@ -818,7 +819,7 @@ size_t ZSTD_compressBlock_fast_generic(ZSTD_CCtx* zc,
if (ip <= ilimit) if (ip <= ilimit)
{ {
/* Fill Table */ /* Fill Table */
hashTable[ZSTD_hashPtr(ip-(mlCode+MINMATCH)+2, hBits, mls)] = (U32)(ip-(mlCode+MINMATCH)+2-base); /* here because ip-(mlCode+MINMATCH)+2 could be > iend-8 without ip <= ilimit check*/ hashTable[ZSTD_hashPtr(base+current+2, hBits, mls)] = current+2; /* here because current+2 could be > iend-8 without ip <= ilimit check*/
hashTable[ZSTD_hashPtr(ip-2, hBits, mls)] = (U32)(ip-2-base); hashTable[ZSTD_hashPtr(ip-2, hBits, mls)] = (U32)(ip-2-base);
/* check immediate repcode */ /* check immediate repcode */
while ( (ip <= ilimit) while ( (ip <= ilimit)