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Make compression 5% faster

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emmanuel-marty 2019-04-20 16:24:54 +02:00
parent fb79d319cb
commit 6c4a86c9fe
1 changed files with 25 additions and 27 deletions
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52
src/shrink.c
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@ -514,7 +514,7 @@ static void lzsa_optimize_matches(lsza_compressor *pCompressor, const int nStart
lzsa_match *pMatch = pCompressor->match + (i << MATCHES_PER_OFFSET_SHIFT);
int m;
for (m = 0; m < NMATCHES_PER_OFFSET; m++) {
for (m = 0; m < NMATCHES_PER_OFFSET && pMatch[m].length >= MIN_MATCH_SIZE; m++) {
int nMatchOffsetSize = (pMatch[m].offset <= 256) ? 1 : 2;
if (pMatch[m].length >= LEAVE_ALONE_MATCH_SIZE) {
@ -534,41 +534,39 @@ static void lzsa_optimize_matches(lsza_compressor *pCompressor, const int nStart
}
}
else {
if (pMatch[m].length >= MIN_MATCH_SIZE) {
int nMatchLen = pMatch[m].length;
int k, nMatchRunLen;
int nMatchLen = pMatch[m].length;
int k, nMatchRunLen;
if ((i + nMatchLen) > (nEndOffset - LAST_LITERALS))
nMatchLen = nEndOffset - LAST_LITERALS - i;
if ((i + nMatchLen) > (nEndOffset - LAST_LITERALS))
nMatchLen = nEndOffset - LAST_LITERALS - i;
nMatchRunLen = nMatchLen;
if (nMatchRunLen > MATCH_RUN_LEN)
nMatchRunLen = MATCH_RUN_LEN;
nMatchRunLen = nMatchLen;
if (nMatchRunLen > MATCH_RUN_LEN)
nMatchRunLen = MATCH_RUN_LEN;
for (k = MIN_MATCH_SIZE; k < nMatchRunLen; k++) {
int nCurCost;
for (k = MIN_MATCH_SIZE; k < nMatchRunLen; k++) {
int nCurCost;
nCurCost = 1 + nMatchOffsetSize /* no extra match len bytes */;
nCurCost += cost[i + k];
nCurCost = 1 + nMatchOffsetSize /* no extra match len bytes */;
nCurCost += cost[i + k];
if (nBestCost >= nCurCost) {
nBestCost = nCurCost;
nBestMatchLen = k;
nBestMatchOffset = pMatch[m].offset;
}
if (nBestCost >= nCurCost) {
nBestCost = nCurCost;
nBestMatchLen = k;
nBestMatchOffset = pMatch[m].offset;
}
}
for (; k <= nMatchLen; k++) {
int nCurCost;
for (; k <= nMatchLen; k++) {
int nCurCost;
nCurCost = 1 + nMatchOffsetSize + lzsa_get_match_varlen_size(k - MIN_MATCH_SIZE);
nCurCost += cost[i + k];
nCurCost = 1 + nMatchOffsetSize + lzsa_get_match_varlen_size(k - MIN_MATCH_SIZE);
nCurCost += cost[i + k];
if (nBestCost >= nCurCost) {
nBestCost = nCurCost;
nBestMatchLen = k;
nBestMatchOffset = pMatch[m].offset;
}
if (nBestCost >= nCurCost) {
nBestCost = nCurCost;
nBestMatchLen = k;
nBestMatchOffset = pMatch[m].offset;
}
}
}