diff options
| author | Yann Collet <cyan@fb.com> | 2017-10-09 08:44:05 (GMT) |
|---|---|---|
| committer | Yann Collet <cyan@fb.com> | 2017-10-09 08:44:05 (GMT) |
| commit | 97c18f5f0edf89fb7846bc2923bdc1568a2d95c1 (patch) | |
| tree | f391c94e250898643537e8f9a8eef718dcbce36f | |
| parent | bdca63ed69dc1873b385c87b25d64fa5ebd595f7 (diff) | |
| download | lz4-97c18f5f0edf89fb7846bc2923bdc1568a2d95c1.zip lz4-97c18f5f0edf89fb7846bc2923bdc1568a2d95c1.tar.gz lz4-97c18f5f0edf89fb7846bc2923bdc1568a2d95c1.tar.bz2 | |
re-inserted last byte test in widerMatch
| -rw-r--r-- | lib/lz4hc.c | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/lib/lz4hc.c b/lib/lz4hc.c index 19636c5..bd75911 100644 --- a/lib/lz4hc.c +++ b/lib/lz4hc.c @@ -181,6 +181,7 @@ LZ4_FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( const BYTE* const lowPrefixPtr = base + dictLimit; const U32 lowLimit = (hc4->lowLimit + 64 KB > (U32)(ip-base)) ? hc4->lowLimit : (U32)(ip - base) - MAX_DISTANCE; const BYTE* const dictBase = hc4->dictBase; + int const delta = (int)(ip-iLowLimit); int nbAttempts = maxNbAttempts; reg_t const pattern = LZ4_read_ARCH(ip); U32 matchIndex; @@ -196,26 +197,28 @@ LZ4_FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch ( nbAttempts--; if (matchIndex >= dictLimit) { const BYTE* const matchPtr = base + matchIndex; - if (LZ4_read32(matchPtr) == (U32)pattern) { - int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); -#if 0 - /* more generic but unfortunately slower ... */ - int const back = LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr); -#else - int back = 0; - while ( (ip+back > iLowLimit) - && (matchPtr+back > lowPrefixPtr) - && (ip[back-1] == matchPtr[back-1])) { - back--; - } -#endif - mlt -= back; + if (*(iLowLimit + longest) == *(matchPtr - delta + longest)) { + if (LZ4_read32(matchPtr) == (U32)pattern) { + int mlt = MINMATCH + LZ4_count(ip+MINMATCH, matchPtr+MINMATCH, iHighLimit); + #if 0 + /* more generic but unfortunately slower ... */ + int const back = LZ4HC_countBack(ip, matchPtr, iLowLimit, lowPrefixPtr); + #else + int back = 0; + while ( (ip+back > iLowLimit) + && (matchPtr+back > lowPrefixPtr) + && (ip[back-1] == matchPtr[back-1])) { + back--; + } + #endif + mlt -= back; - if (mlt > longest) { - longest = mlt; - *matchpos = matchPtr+back; - *startpos = ip+back; - } } + if (mlt > longest) { + longest = mlt; + *matchpos = matchPtr+back; + *startpos = ip+back; + } } + } } else { /* matchIndex < dictLimit */ const BYTE* const matchPtr = dictBase + matchIndex; if (LZ4_read32(matchPtr) == (U32)pattern) { |