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Compress LZSA2 another 3% faster

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Emmanuel Marty 2020-07-26 10:07:03 +02:00 committed by GitHub
parent 00d1d95625
commit 3fb9dc54b1
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1 changed files with 43 additions and 37 deletions
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src/shrink_block_v2.c
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@ -270,6 +270,7 @@ static void lzsa_insert_forward_match_v2(lzsa_compressor *pCompressor, const uns
*/
static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigned char *pInWindow, lzsa_match *pBestMatch, const int nStartOffset, const int nEndOffset, const int nReduce, const int nInsertForwardReps, const int nArrivalsPerPosition) {
lzsa_arrival *arrival = pCompressor->arrival - (nStartOffset << ARRIVALS_PER_POSITION_SHIFT);
const int* rle_end = (int*)pCompressor->intervals /* reuse */;
const int nModeSwitchPenalty = (pCompressor->flags & LZSA_FLAG_FAVOR_RATIO) ? 0 : MODESWITCH_PENALTY;
const int nMinMatchSize = pCompressor->min_match_size;
const int nDisableScore = nReduce ? 0 : (2 * BLOCK_SIZE);
@ -377,55 +378,60 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
}
lzsa_match *match = pCompressor->match + ((i - nStartOffset) << MATCHES_PER_INDEX_SHIFT_V2);
int nNumArrivalsForThisPos = j;
int nNumArrivalsForThisPos = j, nMaxOverallRepLen = 0;
int nMinRepLen[NARRIVALS_PER_POSITION_V2_BIG];
memset(nMinRepLen, 0, nArrivalsPerPosition * sizeof(int));
for (j = 0; j < nNumArrivalsForThisPos; j++) {
int nRepOffset = cur_arrival[j].rep_offset;
if (nRepOffset) {
if (i > nRepOffset &&
(i + MIN_MATCH_SIZE_V2) <= nEndOffset) {
if (pInWindow[i] == pInWindow[i - nRepOffset]) {
int nMaxRepLen = nEndOffset - i;
if (nMaxRepLen > LCP_MAX)
nMaxRepLen = LCP_MAX;
const unsigned char* pInWindowAtPos = pInWindow + i;
const unsigned char* pInWindowMax = pInWindow + i + nMaxRepLen;
int nLen0 = rle_end[i - nRepOffset] - (i - nRepOffset);
int nLen1 = rle_end[i] - (i);
int nMinLen = (nLen0 < nLen1) ? nLen0 : nLen1;
int nCurMaxRepLen;
if (nMinLen > nMaxRepLen)
nMinLen = nMaxRepLen;
pInWindowAtPos += nMinLen;
while ((pInWindowAtPos + 8) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 8))
pInWindowAtPos += 8;
while ((pInWindowAtPos + 4) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 4))
pInWindowAtPos += 4;
while (pInWindowAtPos < pInWindowMax && pInWindowAtPos[-nRepOffset] == pInWindowAtPos[0])
pInWindowAtPos++;
nCurMaxRepLen = (int)(pInWindowAtPos - (pInWindow + i));
nMinRepLen[j] = nCurMaxRepLen;
if (nMaxOverallRepLen < nCurMaxRepLen)
nMaxOverallRepLen = nCurMaxRepLen;
}
}
}
}
for (m = 0; m < NMATCHES_PER_INDEX_V2 && match[m].length; m++) {
int nMatchLen = match[m].length & 0x7fff;
int nMatchOffset = match[m].offset;
int nScorePenalty = 3 + ((match[m].length & 0x8000) >> 15);
int nNoRepmatchOffsetCost = (nMatchOffset <= 32) ? 4 : ((nMatchOffset <= 512) ? 8 : ((nMatchOffset <= (8192 + 512)) ? 12 : 16));
int nStartingMatchLen, nMaxOverallRepLen = 0, k;
int nMaxRepLen[NARRIVALS_PER_POSITION_V2_BIG];
int nStartingMatchLen, k;
if ((i + nMatchLen) > nEndOffset)
nMatchLen = nEndOffset - i;
for (j = 0; j < nNumArrivalsForThisPos; j++) {
int nRepOffset = cur_arrival[j].rep_offset;
int nCurMaxRepLen = 0;
if (nRepOffset) {
if (nMatchOffset == nRepOffset)
nCurMaxRepLen = nMatchLen;
else {
if (i > nRepOffset &&
(i - nRepOffset + nMatchLen) <= nEndOffset) {
nCurMaxRepLen = nMinRepLen[j];
const unsigned char *pInWindowAtPos = pInWindow + i + nCurMaxRepLen;
const unsigned char *pInWindowMax = pInWindow + i + nMatchLen;
while ((pInWindowAtPos + 8) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 8))
pInWindowAtPos += 8;
while ((pInWindowAtPos + 4) < pInWindowMax && !memcmp(pInWindowAtPos - nRepOffset, pInWindowAtPos, 4))
pInWindowAtPos += 4;
while (pInWindowAtPos < pInWindowMax && pInWindowAtPos[-nRepOffset] == pInWindowAtPos[0])
pInWindowAtPos++;
nCurMaxRepLen = (int)(pInWindowAtPos - (pInWindow + i));
nMinRepLen[j] = nCurMaxRepLen;
}
}
if (nMaxOverallRepLen < nCurMaxRepLen)
nMaxOverallRepLen = nCurMaxRepLen;
}
nMaxRepLen[j] = nCurMaxRepLen;
}
while (j < nArrivalsPerPosition)
nMaxRepLen[j++] = 0;
if (nInsertForwardReps)
lzsa_insert_forward_match_v2(pCompressor, pInWindow, i, nMatchOffset, nStartOffset, nEndOffset, 0);
@ -544,7 +550,7 @@ static void lzsa_optimize_forward_v2(lzsa_compressor *pCompressor, const unsigne
if (k <= nMaxOverallRepLen) {
for (j = 0; j < nNumArrivalsForThisPos; j++) {
if (nMaxRepLen[j] >= k) {
if (nMinRepLen[j] >= k) {
const int nPrevCost = cur_arrival[j].cost & 0x3fffffff;
int nRepCodingChoiceCost = nPrevCost /* the actual cost of the literals themselves accumulates up the chain */ + nMatchLenCost;
int nScore = cur_arrival[j].score + 2;