ddidderr/zstd-rs
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speed up small blocks

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This commit is contained in:
Nick Terrell
2020-08-16 23:03:38 -07:00
parent a8006264cf
commit 6004c1117f
6 changed files with 143 additions and 59 deletions
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lib/compress/fse_compress.c
+4 -17
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@@ -341,6 +341,8 @@ unsigned FSE_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxS
return FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 2);
}
// TODO: Emit -1 based on # of symbols
#define LOW_PROB 0
/* Secondary normalization method.
To be used when primary method fails. */
@@ -361,7 +363,7 @@ static size_t FSE_normalizeM2(short* norm, U32 tableLog, const unsigned* count,
norm[s]=0;
continue;
}
if (count[s] <= lowThreshold) {
if (LOW_PROB && count[s] <= lowThreshold) {
norm[s] = -1;
distributed++;
total -= count[s];
@@ -431,7 +433,6 @@ static size_t FSE_normalizeM2(short* norm, U32 tableLog, const unsigned* count,
return 0;
}
size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog,
const unsigned* count, size_t total,
unsigned maxSymbolValue)
@@ -455,7 +456,7 @@ size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog,
for (s=0; s<=maxSymbolValue; s++) {
if (count[s] == total) return 0; /* rle special case */
if (count[s] == 0) { normalizedCounter[s]=0; continue; }
if (count[s] <= lowThreshold) {
if (LOW_PROB && count[s] <= lowThreshold) {
normalizedCounter[s] = -1;
stillToDistribute--;
} else {
@@ -476,20 +477,6 @@ size_t FSE_normalizeCount (short* normalizedCounter, unsigned tableLog,
else normalizedCounter[largest] += (short)stillToDistribute;
}
#if 0
{ /* Print Table (debug) */
U32 s;
U32 nTotal = 0;
for (s=0; s<=maxSymbolValue; s++)
RAWLOG(2, "%3i: %4i \n", s, normalizedCounter[s]);
for (s=0; s<=maxSymbolValue; s++)
nTotal += abs(normalizedCounter[s]);
if (nTotal != (1U<<tableLog))
RAWLOG(2, "Warning !!! Total == %u != %u !!!", nTotal, 1U<<tableLog);
getchar();
}
#endif
return tableLog;
}