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new initializer for ll price

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This commit is contained in:
Yann Collet
2021-09-03 16:07:31 -07:00
parent f0fc8cb3e1
commit 27a8bbe265
3 changed files with 102 additions and 74 deletions
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lib/compress/zstd_opt.c
+34 -13
View File
@@ -24,11 +24,11 @@
* Price functions for optimal parser
***************************************/
#if 0 /* approximation at bit level */
#if 0 /* approximation at bit level (for tests) */
# define BITCOST_ACCURACY 0
# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
# define WEIGHT(stat) ((void)opt, ZSTD_bitWeight(stat))
#elif 0 /* fractional bit accuracy */
# define WEIGHT(stat, opt) ((void)opt, ZSTD_bitWeight(stat))
#elif 0 /* fractional bit accuracy (for tests) */
# define BITCOST_ACCURACY 8
# define BITCOST_MULTIPLIER (1 << BITCOST_ACCURACY)
# define WEIGHT(stat,opt) ((void)opt, ZSTD_fracWeight(stat))
@@ -94,10 +94,21 @@ static U32 ZSTD_downscaleStat(unsigned* table, U32 lastEltIndex, int malus)
return sum;
}
static U32 sum_u32(const unsigned table[], size_t nbElts)
{
size_t n;
U32 total = 0;
for (n=0; n<nbElts; n++) {
total += table[n];
}
return total;
}
/* ZSTD_rescaleFreqs() :
* if first block (detected by optPtr->litLengthSum == 0) : init statistics
* take hints from dictionary if there is one
* or init from zero, using src for literals stats, or flat 1 for match symbols
* and init from zero if there is none,
* using src for literals stats, and baseline stats for sequence symbols
* otherwise downscale existing stats, to be used as seed for next block.
*/
static void
@@ -177,11 +188,16 @@ ZSTD_rescaleFreqs(optState_t* const optPtr,
optPtr->litSum = ZSTD_downscaleStat(optPtr->litFreq, MaxLit, 1);
}
{ unsigned ll;
for (ll=0; ll<=MaxLL; ll++)
optPtr->litLengthFreq[ll] = 1;
{ unsigned const baseLLfreqs[MaxLL+1] = {
4, 2, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1
};
memcpy(optPtr->litLengthFreq, baseLLfreqs, sizeof(baseLLfreqs)); optPtr->litLengthSum = sum_u32(baseLLfreqs, MaxLL+1);
//unsigned ll; for (ll=0; ll<=MaxLL; ll++) optPtr->litLengthFreq[ll] = 1; optPtr->litLengthSum = MaxLL+1;
}
optPtr->litLengthSum = MaxLL+1;
{ unsigned ml;
for (ml=0; ml<=MaxML; ml++)
@@ -189,11 +205,16 @@ ZSTD_rescaleFreqs(optState_t* const optPtr,
}
optPtr->matchLengthSum = MaxML+1;
{ unsigned of;
for (of=0; of<=MaxOff; of++)
optPtr->offCodeFreq[of] = 1;
{ unsigned const baseOFCfreqs[MaxOff+1] = {
8, 4, 3, 3, 3, 4, 4, 4,
4, 4, 3, 3, 3, 2, 2, 2,
1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1,
};
//memcpy(optPtr->offCodeFreq, baseOFCfreqs, sizeof(baseOFCfreqs)); optPtr->offCodeSum = sum_u32(baseOFCfreqs, MaxOff+1);
unsigned of; for (of=0; of<=MaxOff; of++) optPtr->offCodeFreq[of] = 1; optPtr->offCodeSum = MaxOff+1;
}
optPtr->offCodeSum = MaxOff+1;
}
@@ -901,11 +922,11 @@ static void ZSTD_optLdm_processMatchCandidate(ZSTD_optLdm_t* optLdm, ZSTD_match_
ZSTD_optLdm_maybeAddMatch(matches, nbMatches, optLdm, currPosInBlock);
}
/*-*******************************
* Optimal parser
*********************************/
static U32 ZSTD_totalLen(ZSTD_optimal_t sol)
{
return sol.litlen + sol.mlen;
lib/dictBuilder/zdict.c
+16 -9
View File
@@ -139,7 +139,7 @@ static unsigned ZDICT_NbCommonBytes (size_t val)
_BitScanForward64( &r, (U64)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctzll((U64)val) >> 3);
return (unsigned)(__builtin_ctzll((U64)val) >> 3);
# else
static const int DeBruijnBytePos[64] = { 0, 0, 0, 0, 0, 1, 1, 2, 0, 3, 1, 3, 1, 4, 2, 7, 0, 2, 3, 6, 1, 5, 3, 5, 1, 3, 4, 4, 2, 5, 6, 7, 7, 0, 1, 2, 3, 3, 4, 6, 2, 6, 5, 5, 3, 4, 5, 6, 7, 1, 2, 4, 6, 4, 4, 5, 7, 2, 6, 5, 7, 6, 7, 7 };
return DeBruijnBytePos[((U64)((val & -(long long)val) * 0x0218A392CDABBD3FULL)) >> 58];
@@ -150,7 +150,7 @@ static unsigned ZDICT_NbCommonBytes (size_t val)
_BitScanForward( &r, (U32)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_ctz((U32)val) >> 3);
return (unsigned)(__builtin_ctz((U32)val) >> 3);
# else
static const int DeBruijnBytePos[32] = { 0, 0, 3, 0, 3, 1, 3, 0, 3, 2, 2, 1, 3, 2, 0, 1, 3, 3, 1, 2, 2, 2, 2, 0, 3, 1, 2, 0, 1, 0, 1, 1 };
return DeBruijnBytePos[((U32)((val & -(S32)val) * 0x077CB531U)) >> 27];
@@ -163,7 +163,7 @@ static unsigned ZDICT_NbCommonBytes (size_t val)
_BitScanReverse64( &r, val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clzll(val) >> 3);
return (unsigned)(__builtin_clzll(val) >> 3);
# else
unsigned r;
const unsigned n32 = sizeof(size_t)*4; /* calculate this way due to compiler complaining in 32-bits mode */
@@ -178,7 +178,7 @@ static unsigned ZDICT_NbCommonBytes (size_t val)
_BitScanReverse( &r, (unsigned long)val );
return (unsigned)(r>>3);
# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clz((U32)val) >> 3);
return (unsigned)(__builtin_clz((U32)val) >> 3);
# else
unsigned r;
if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
@@ -235,7 +235,7 @@ static dictItem ZDICT_analyzePos(
U32 savings[LLIMIT] = {0};
const BYTE* b = (const BYTE*)buffer;
size_t maxLength = LLIMIT;
size_t pos = suffix[start];
size_t pos = (size_t)suffix[start];
U32 end = start;
dictItem solution;
@@ -369,7 +369,7 @@ static dictItem ZDICT_analyzePos(
savings[i] = savings[i-1] + (lengthList[i] * (i-3));
DISPLAYLEVEL(4, "Selected dict at position %u, of length %u : saves %u (ratio: %.2f) \n",
(unsigned)pos, (unsigned)maxLength, (unsigned)savings[maxLength], (double)savings[maxLength] / maxLength);
(unsigned)pos, (unsigned)maxLength, (unsigned)savings[maxLength], (double)savings[maxLength] / (double)maxLength);
solution.pos = (U32)pos;
solution.length = (U32)maxLength;
@@ -379,7 +379,7 @@ static dictItem ZDICT_analyzePos(
{ U32 id;
for (id=start; id<end; id++) {
U32 p, pEnd, length;
U32 const testedPos = suffix[id];
U32 const testedPos = (U32)suffix[id];
if (testedPos == pos)
length = solution.length;
else {
@@ -442,7 +442,7 @@ static U32 ZDICT_tryMerge(dictItem* table, dictItem elt, U32 eltNbToSkip, const
if ((table[u].pos + table[u].length >= elt.pos) && (table[u].pos < elt.pos)) { /* overlap, existing < new */
/* append */
int const addedLength = (int)eltEnd - (table[u].pos + table[u].length);
int const addedLength = (int)eltEnd - (int)(table[u].pos + table[u].length);
table[u].savings += elt.length / 8; /* rough approx bonus */
if (addedLength > 0) { /* otherwise, elt fully included into existing */
table[u].length += addedLength;
@@ -766,6 +766,13 @@ static size_t ZDICT_analyzeEntropy(void* dstBuffer, size_t maxDstSize,
pos += fileSizes[u];
}
if (notificationLevel >= 4) {
/* writeStats */
DISPLAYLEVEL(4, "Offset Code Frequencies : \n");
for (u=0; u<=offcodeMax; u++) {
DISPLAYLEVEL(4, "%2u :%7u \n", u, offcodeCount[u]);
} }
/* analyze, build stats, starting with literals */
{ size_t maxNbBits = HUF_buildCTable (hufTable, countLit, 255, huffLog);
if (HUF_isError(maxNbBits)) {
@@ -872,7 +879,7 @@ static size_t ZDICT_analyzeEntropy(void* dstBuffer, size_t maxDstSize,
MEM_writeLE32(dstPtr+8, bestRepOffset[2].offset);
#else
/* at this stage, we don't use the result of "most common first offset",
as the impact of statistics is not properly evaluated */
* as the impact of statistics is not properly evaluated */
MEM_writeLE32(dstPtr+0, repStartValue[0]);
MEM_writeLE32(dstPtr+4, repStartValue[1]);
MEM_writeLE32(dstPtr+8, repStartValue[2]);