****************************************************************/
MEM_STATIC unsigned BIT_highbit32 (register U32 val)
{
-# if defined(_MSC_VER) /* Visual */
- unsigned long r=0;
- _BitScanReverse ( &r, val );
- return (unsigned) r;
-# elif defined(__GNUC__) && (__GNUC__ >= 3) /* Use GCC Intrinsic */
- return 31 - __builtin_clz (val);
-# else /* Software version */
- static const unsigned DeBruijnClz[32] = { 0, 9, 1, 10, 13, 21, 2, 29, 11, 14, 16, 18, 22, 25, 3, 30, 8, 12, 20, 28, 15, 17, 24, 7, 19, 27, 23, 6, 26, 5, 4, 31 };
- U32 v = val;
- v |= v >> 1;
- v |= v >> 2;
- v |= v >> 4;
- v |= v >> 8;
- v |= v >> 16;
- return DeBruijnClz[ (U32) (v * 0x07C4ACDDU) >> 27];
-# endif
+ return 31 - __builtin_clz(val);
}
/*===== Local Constants =====*/
return op - ostart;
}
-#if 0 /* for debug */
-# define STORESEQ_DEBUG
-U32 g_startDebug = 0;
-const BYTE* g_start = NULL;
-#endif
-
/*! ZSTD_storeSeq() :
Store a sequence (literal length, literals, offset code and match length code) into seqStore_t.
`offsetCode` : distance to match, or 0 == repCode.
*/
MEM_STATIC void ZSTD_storeSeq(seqStore_t* seqStorePtr, size_t litLength, const void* literals, U32 offsetCode, size_t matchCode)
{
-#ifdef STORESEQ_DEBUG
- if (g_startDebug) {
- const U32 pos = (U32)((const BYTE*)literals - g_start);
- if (g_start==NULL) g_start = (const BYTE*)literals;
- if ((pos > 1895000) && (pos < 1895300))
- fprintf(stderr, "Cpos %6u :%5u literals & match %3u bytes at distance %6u \n",
- pos, (U32)litLength, (U32)matchCode+MINMATCH, (U32)offsetCode);
- }
-#endif
/* copy Literals */
ZSTD_wildcopy(seqStorePtr->lit, literals, litLength);
seqStorePtr->lit += litLength;
{
if (MEM_isLittleEndian()) {
if (MEM_64bits()) {
-# if defined(_MSC_VER) && defined(_WIN64)
- unsigned long r = 0;
- _BitScanForward64( &r, (U64)val );
- return (unsigned)(r>>3);
-# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__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];
-# endif
} else { /* 32 bits */
-# if defined(_MSC_VER)
- unsigned long r=0;
- _BitScanForward( &r, (U32)val );
- return (unsigned)(r>>3);
-# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__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];
-# endif
}
} else { /* Big Endian CPU */
if (MEM_64bits()) {
-# if defined(_MSC_VER) && defined(_WIN64)
- unsigned long r = 0;
- _BitScanReverse64( &r, val );
- return (unsigned)(r>>3);
-# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__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 */
- if (!(val>>n32)) { r=4; } else { r=0; val>>=n32; }
- if (!(val>>16)) { r+=2; val>>=8; } else { val>>=24; }
- r += (!val);
- return r;
-# endif
} else { /* 32 bits */
-# if defined(_MSC_VER)
- unsigned long r = 0;
- _BitScanReverse( &r, (unsigned long)val );
- return (unsigned)(r>>3);
-# elif defined(__GNUC__) && (__GNUC__ >= 3)
return (__builtin_clz((U32)val) >> 3);
-# else
- unsigned r;
- if (!(val>>16)) { r=2; val>>=8; } else { r=0; val>>=24; }
- r += (!val);
- return r;
-# endif
} }
}
U32 const windowLow = zc->lowLimit;
U32 matchEndIdx = curr+8;
size_t bestLength = 8;
-#ifdef ZSTD_C_PREDICT
- U32 predictedSmall = *(bt + 2*((curr-1)&btMask) + 0);
- U32 predictedLarge = *(bt + 2*((curr-1)&btMask) + 1);
- predictedSmall += (predictedSmall>0);
- predictedLarge += (predictedLarge>0);
-#endif /* ZSTD_C_PREDICT */
hashTable[h] = curr; /* Update Hash Table */
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
-#ifdef ZSTD_C_PREDICT /* note : can create issues when hlog small <= 11 */
- const U32* predictPtr = bt + 2*((matchIndex-1) & btMask); /* written this way, as bt is a roll buffer */
- if (matchIndex == predictedSmall) {
- /* no need to check length, result known */
- *smallerPtr = matchIndex;
- if (matchIndex <= btLow) { smallerPtr=&dummy32; break; } /* beyond tree size, stop the search */
- smallerPtr = nextPtr+1; /* new "smaller" => larger of match */
- matchIndex = nextPtr[1]; /* new matchIndex larger than previous (closer to curr) */
- predictedSmall = predictPtr[1] + (predictPtr[1]>0);
- continue;
- }
- if (matchIndex == predictedLarge) {
- *largerPtr = matchIndex;
- if (matchIndex <= btLow) { largerPtr=&dummy32; break; } /* beyond tree size, stop the search */
- largerPtr = nextPtr;
- matchIndex = nextPtr[0];
- predictedLarge = predictPtr[0] + (predictPtr[0]>0);
- continue;
- }
-#endif
if ((!extDict) || (matchIndex+matchLength >= dictLimit)) {
match = base + matchIndex;
if (match[matchLength] == ip[matchLength])
memcpy(dstDCtx, srcDCtx, sizeof(ZSTD_DCtx) - workSpaceSize); /* no need to copy workspace */
}
-#if 0
-/* deprecated */
-static void ZSTD_refDCtx(ZSTD_DCtx* dstDCtx, const ZSTD_DCtx* srcDCtx)
-{
- ZSTD_decompressBegin(dstDCtx); /* init */
- if (srcDCtx) { /* support refDCtx on NULL */
- dstDCtx->dictEnd = srcDCtx->dictEnd;
- dstDCtx->vBase = srcDCtx->vBase;
- dstDCtx->base = srcDCtx->base;
- dstDCtx->previousDstEnd = srcDCtx->previousDstEnd;
- dstDCtx->dictID = srcDCtx->dictID;
- dstDCtx->litEntropy = srcDCtx->litEntropy;
- dstDCtx->fseEntropy = srcDCtx->fseEntropy;
- dstDCtx->LLTptr = srcDCtx->entropy.LLTable;
- dstDCtx->MLTptr = srcDCtx->entropy.MLTable;
- dstDCtx->OFTptr = srcDCtx->entropy.OFTable;
- dstDCtx->HUFptr = srcDCtx->entropy.hufTable;
- dstDCtx->entropy.rep[0] = srcDCtx->entropy.rep[0];
- dstDCtx->entropy.rep[1] = srcDCtx->entropy.rep[1];
- dstDCtx->entropy.rep[2] = srcDCtx->entropy.rep[2];
- }
-}
-#endif
-
static void ZSTD_refDDict(ZSTD_DCtx* dstDCtx, const ZSTD_DDict* ddict);
const BYTE* match = sequence.match;
/* check */
-#if 1
if (oMatchEnd>oend) return ERROR(dstSize_tooSmall); /* last match must start at a minimum distance of WILDCOPY_OVERLENGTH from oend */
if (iLitEnd > litLimit) return ERROR(corruption_detected); /* over-read beyond lit buffer */
if (oLitEnd>oend_w) return ZSTD_execSequenceLast7(op, oend, sequence, litPtr, litLimit, base, vBase, dictEnd);
-#endif
/* copy Literals */
ZSTD_copy8(op, *litPtr);
*litPtr = iLitEnd; /* update for next sequence */
/* copy Match */
-#if 1
if (sequence.offset > (size_t)(oLitEnd - base)) {
/* offset beyond prefix */
if (sequence.offset > (size_t)(oLitEnd - vBase)) return ERROR(corruption_detected);
}
} }
/* Requirement: op <= oend_w && sequence.matchLength >= MINMATCH */
-#endif
/* match within prefix */
if (sequence.offset < 8) {
projects / thirdparty / zstd.git / commitdiff
