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huf log speed optimization: unidirectional scan of logs + break when regressing

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This commit is contained in:
Danielle Rozenblit
2022-12-20 12:27:38 -08:00
parent c2638212af
commit 482689b995
21 changed files with 96 additions and 77 deletions
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lib/compress/huf_compress.c
+8 -24
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@@ -1253,14 +1253,6 @@ unsigned HUF_minTableLog(unsigned symbolCardinality)
return minBitsSymbols;
}
#define ESTIMATE_TOTAL_SIZE(huffLog) {\
maxBits = HUF_buildCTable_wksp(table, count, maxSymbolValue, huffLog, workSpace, wkspSize);\
if (ERR_isError(maxBits)) continue;\
hSize = HUF_writeCTable_wksp(dst, dstSize, table, maxSymbolValue, (U32)maxBits, workSpace, wkspSize);\
if (ERR_isError(hSize)) continue;\
newSize = HUF_estimateCompressedSize(table, count, maxSymbolValue) + hSize;\
}\
unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxSymbolValue, void* workSpace, size_t wkspSize, HUF_CElt* table, const unsigned* count, HUF_depth_mode depthMode)
{
unsigned optLog = FSE_optimalTableLog_internal(maxTableLog, srcSize, maxSymbolValue, 1);
@@ -1273,28 +1265,20 @@ unsigned HUF_optimalTableLog(unsigned maxTableLog, size_t srcSize, unsigned maxS
const unsigned symbolCardinality = HUF_cardinality(count, maxSymbolValue);
const unsigned minTableLog = HUF_minTableLog(symbolCardinality);
size_t optSize = ((size_t) ~0);
unsigned optLogGuess = optLog;
if (wkspSize < sizeof(HUF_buildCTable_wksp_tables)) return optLog; /** Assert workspace is large enough **/
/* Search below estimate log until size increases */
for (; optLogGuess >= minTableLog; optLogGuess--) {
ESTIMATE_TOTAL_SIZE(optLogGuess);
/* Search until size increases */
for (unsigned optLogGuess = minTableLog; optLogGuess <= maxTableLog; optLogGuess++) {
maxBits = HUF_buildCTable_wksp(table, count, maxSymbolValue, optLogGuess, workSpace, wkspSize);
if (newSize > optSize) {
break;
}
optSize = newSize;
optLog = optLogGuess;
}
if (ERR_isError(maxBits)) continue;
if (optSize < ((size_t) ~0)) {
return optLog;
}
hSize = HUF_writeCTable_wksp(dst, dstSize, table, maxSymbolValue, (U32)maxBits, workSpace, wkspSize);
/* Search above estimate log until size increases */
for (; optLogGuess <= maxTableLog; optLogGuess++) {
ESTIMATE_TOTAL_SIZE(optLogGuess);
if (ERR_isError(hSize)) continue;
newSize = HUF_estimateCompressedSize(table, count, maxSymbolValue) + hSize;
if (newSize > optSize) {
break;