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Diffstat (limited to 'thirdparty/zstd/compress/zstd_lazy.c')
-rw-r--r--thirdparty/zstd/compress/zstd_lazy.c1044
1 files changed, 482 insertions, 562 deletions
diff --git a/thirdparty/zstd/compress/zstd_lazy.c b/thirdparty/zstd/compress/zstd_lazy.c
index 3d523e8472..2e38dcb46d 100644
--- a/thirdparty/zstd/compress/zstd_lazy.c
+++ b/thirdparty/zstd/compress/zstd_lazy.c
@@ -61,7 +61,7 @@ ZSTD_updateDUBT(ZSTD_matchState_t* ms,
* assumption : curr >= btlow == (curr - btmask)
* doesn't fail */
static void
-ZSTD_insertDUBT1(ZSTD_matchState_t* ms,
+ZSTD_insertDUBT1(const ZSTD_matchState_t* ms,
U32 curr, const BYTE* inputEnd,
U32 nbCompares, U32 btLow,
const ZSTD_dictMode_e dictMode)
@@ -93,7 +93,7 @@ ZSTD_insertDUBT1(ZSTD_matchState_t* ms,
assert(curr >= btLow);
assert(ip < iend); /* condition for ZSTD_count */
- while (nbCompares-- && (matchIndex > windowLow)) {
+ for (; nbCompares && (matchIndex > windowLow); --nbCompares) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
assert(matchIndex < curr);
@@ -151,7 +151,7 @@ ZSTD_insertDUBT1(ZSTD_matchState_t* ms,
static size_t
ZSTD_DUBT_findBetterDictMatch (
- ZSTD_matchState_t* ms,
+ const ZSTD_matchState_t* ms,
const BYTE* const ip, const BYTE* const iend,
size_t* offsetPtr,
size_t bestLength,
@@ -185,7 +185,7 @@ ZSTD_DUBT_findBetterDictMatch (
(void)dictMode;
assert(dictMode == ZSTD_dictMatchState);
- while (nbCompares-- && (dictMatchIndex > dictLowLimit)) {
+ for (; nbCompares && (dictMatchIndex > dictLowLimit); --nbCompares) {
U32* const nextPtr = dictBt + 2*(dictMatchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match = dictBase + dictMatchIndex;
@@ -197,8 +197,8 @@ ZSTD_DUBT_findBetterDictMatch (
U32 matchIndex = dictMatchIndex + dictIndexDelta;
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(curr-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) ) {
DEBUGLOG(9, "ZSTD_DUBT_findBetterDictMatch(%u) : found better match length %u -> %u and offsetCode %u -> %u (dictMatchIndex %u, matchIndex %u)",
- curr, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, ZSTD_REP_MOVE + curr - matchIndex, dictMatchIndex, matchIndex);
- bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + curr - matchIndex;
+ curr, (U32)bestLength, (U32)matchLength, (U32)*offsetPtr, STORE_OFFSET(curr - matchIndex), dictMatchIndex, matchIndex);
+ bestLength = matchLength, *offsetPtr = STORE_OFFSET(curr - matchIndex);
}
if (ip+matchLength == iend) { /* reached end of input : ip[matchLength] is not valid, no way to know if it's larger or smaller than match */
break; /* drop, to guarantee consistency (miss a little bit of compression) */
@@ -218,7 +218,7 @@ ZSTD_DUBT_findBetterDictMatch (
}
if (bestLength >= MINMATCH) {
- U32 const mIndex = curr - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
+ U32 const mIndex = curr - (U32)STORED_OFFSET(*offsetPtr); (void)mIndex;
DEBUGLOG(8, "ZSTD_DUBT_findBetterDictMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
curr, (U32)bestLength, (U32)*offsetPtr, mIndex);
}
@@ -309,7 +309,7 @@ ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms,
matchIndex = hashTable[h];
hashTable[h] = curr; /* Update Hash Table */
- while (nbCompares-- && (matchIndex > windowLow)) {
+ for (; nbCompares && (matchIndex > windowLow); --nbCompares) {
U32* const nextPtr = bt + 2*(matchIndex & btMask);
size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
const BYTE* match;
@@ -328,7 +328,7 @@ ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms,
if (matchLength > matchEndIdx - matchIndex)
matchEndIdx = matchIndex + (U32)matchLength;
if ( (4*(int)(matchLength-bestLength)) > (int)(ZSTD_highbit32(curr-matchIndex+1) - ZSTD_highbit32((U32)offsetPtr[0]+1)) )
- bestLength = matchLength, *offsetPtr = ZSTD_REP_MOVE + curr - matchIndex;
+ bestLength = matchLength, *offsetPtr = STORE_OFFSET(curr - matchIndex);
if (ip+matchLength == iend) { /* equal : no way to know if inf or sup */
if (dictMode == ZSTD_dictMatchState) {
nbCompares = 0; /* in addition to avoiding checking any
@@ -357,6 +357,7 @@ ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms,
*smallerPtr = *largerPtr = 0;
+ assert(nbCompares <= (1U << ZSTD_SEARCHLOG_MAX)); /* Check we haven't underflowed. */
if (dictMode == ZSTD_dictMatchState && nbCompares) {
bestLength = ZSTD_DUBT_findBetterDictMatch(
ms, ip, iend,
@@ -367,7 +368,7 @@ ZSTD_DUBT_findBestMatch(ZSTD_matchState_t* ms,
assert(matchEndIdx > curr+8); /* ensure nextToUpdate is increased */
ms->nextToUpdate = matchEndIdx - 8; /* skip repetitive patterns */
if (bestLength >= MINMATCH) {
- U32 const mIndex = curr - ((U32)*offsetPtr - ZSTD_REP_MOVE); (void)mIndex;
+ U32 const mIndex = curr - (U32)STORED_OFFSET(*offsetPtr); (void)mIndex;
DEBUGLOG(8, "ZSTD_DUBT_findBestMatch(%u) : found match of length %u and offsetCode %u (pos %u)",
curr, (U32)bestLength, (U32)*offsetPtr, mIndex);
}
@@ -390,54 +391,6 @@ ZSTD_BtFindBestMatch( ZSTD_matchState_t* ms,
return ZSTD_DUBT_findBestMatch(ms, ip, iLimit, offsetPtr, mls, dictMode);
}
-
-static size_t
-ZSTD_BtFindBestMatch_selectMLS ( ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
- case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
- case 7 :
- case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
- }
-}
-
-
-static size_t ZSTD_BtFindBestMatch_dictMatchState_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
- case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
- case 7 :
- case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
- }
-}
-
-
-static size_t ZSTD_BtFindBestMatch_extDict_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
- case 5 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
- case 7 :
- case 6 : return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
- }
-}
-
/***********************************
* Dedicated dict search
***********************************/
@@ -450,7 +403,7 @@ void ZSTD_dedicatedDictSearch_lazy_loadDictionary(ZSTD_matchState_t* ms, const B
U32* const chainTable = ms->chainTable;
U32 const chainSize = 1 << ms->cParams.chainLog;
U32 idx = ms->nextToUpdate;
- U32 const minChain = chainSize < target ? target - chainSize : idx;
+ U32 const minChain = chainSize < target - idx ? target - chainSize : idx;
U32 const bucketSize = 1 << ZSTD_LAZY_DDSS_BUCKET_LOG;
U32 const cacheSize = bucketSize - 1;
U32 const chainAttempts = (1 << ms->cParams.searchLog) - cacheSize;
@@ -464,7 +417,7 @@ void ZSTD_dedicatedDictSearch_lazy_loadDictionary(ZSTD_matchState_t* ms, const B
U32 const hashLog = ms->cParams.hashLog - ZSTD_LAZY_DDSS_BUCKET_LOG;
U32* const tmpHashTable = hashTable;
U32* const tmpChainTable = hashTable + ((size_t)1 << hashLog);
- U32 const tmpChainSize = ((1 << ZSTD_LAZY_DDSS_BUCKET_LOG) - 1) << hashLog;
+ U32 const tmpChainSize = (U32)((1 << ZSTD_LAZY_DDSS_BUCKET_LOG) - 1) << hashLog;
U32 const tmpMinChain = tmpChainSize < target ? target - tmpChainSize : idx;
U32 hashIdx;
@@ -608,7 +561,7 @@ size_t ZSTD_dedicatedDictSearch_lazy_search(size_t* offsetPtr, size_t ml, U32 nb
/* save best solution */
if (currentMl > ml) {
ml = currentMl;
- *offsetPtr = curr - (matchIndex + ddsIndexDelta) + ZSTD_REP_MOVE;
+ *offsetPtr = STORE_OFFSET(curr - (matchIndex + ddsIndexDelta));
if (ip+currentMl == iLimit) {
/* best possible, avoids read overflow on next attempt */
return ml;
@@ -645,7 +598,7 @@ size_t ZSTD_dedicatedDictSearch_lazy_search(size_t* offsetPtr, size_t ml, U32 nb
/* save best solution */
if (currentMl > ml) {
ml = currentMl;
- *offsetPtr = curr - (matchIndex + ddsIndexDelta) + ZSTD_REP_MOVE;
+ *offsetPtr = STORE_OFFSET(curr - (matchIndex + ddsIndexDelta));
if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
}
}
@@ -692,7 +645,7 @@ U32 ZSTD_insertAndFindFirstIndex(ZSTD_matchState_t* ms, const BYTE* ip) {
/* inlining is important to hardwire a hot branch (template emulation) */
FORCE_INLINE_TEMPLATE
-size_t ZSTD_HcFindBestMatch_generic (
+size_t ZSTD_HcFindBestMatch(
ZSTD_matchState_t* ms,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
@@ -750,7 +703,7 @@ size_t ZSTD_HcFindBestMatch_generic (
/* save best solution */
if (currentMl > ml) {
ml = currentMl;
- *offsetPtr = curr - matchIndex + ZSTD_REP_MOVE;
+ *offsetPtr = STORE_OFFSET(curr - matchIndex);
if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
}
@@ -758,6 +711,7 @@ size_t ZSTD_HcFindBestMatch_generic (
matchIndex = NEXT_IN_CHAIN(matchIndex, chainMask);
}
+ assert(nbAttempts <= (1U << ZSTD_SEARCHLOG_MAX)); /* Check we haven't underflowed. */
if (dictMode == ZSTD_dedicatedDictSearch) {
ml = ZSTD_dedicatedDictSearch_lazy_search(offsetPtr, ml, nbAttempts, dms,
ip, iLimit, prefixStart, curr, dictLimit, ddsIdx);
@@ -784,7 +738,8 @@ size_t ZSTD_HcFindBestMatch_generic (
/* save best solution */
if (currentMl > ml) {
ml = currentMl;
- *offsetPtr = curr - (matchIndex + dmsIndexDelta) + ZSTD_REP_MOVE;
+ assert(curr > matchIndex + dmsIndexDelta);
+ *offsetPtr = STORE_OFFSET(curr - (matchIndex + dmsIndexDelta));
if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
}
@@ -797,310 +752,80 @@ size_t ZSTD_HcFindBestMatch_generic (
return ml;
}
-
-FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_noDict);
- case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_noDict);
- case 7 :
- case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_noDict);
- }
-}
-
-
-static size_t ZSTD_HcFindBestMatch_dictMatchState_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_dictMatchState);
- case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dictMatchState);
- case 7 :
- case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dictMatchState);
- }
-}
-
-
-static size_t ZSTD_HcFindBestMatch_dedicatedDictSearch_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_dedicatedDictSearch);
- case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_dedicatedDictSearch);
- case 7 :
- case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_dedicatedDictSearch);
- }
-}
-
-
-FORCE_INLINE_TEMPLATE size_t ZSTD_HcFindBestMatch_extDict_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, ZSTD_extDict);
- case 5 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, ZSTD_extDict);
- case 7 :
- case 6 : return ZSTD_HcFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, ZSTD_extDict);
- }
-}
-
/* *********************************
* (SIMD) Row-based matchfinder
***********************************/
/* Constants for row-based hash */
-#define ZSTD_ROW_HASH_TAG_OFFSET 1 /* byte offset of hashes in the match state's tagTable from the beginning of a row */
-#define ZSTD_ROW_HASH_TAG_BITS 8 /* nb bits to use for the tag */
+#define ZSTD_ROW_HASH_TAG_OFFSET 16 /* byte offset of hashes in the match state's tagTable from the beginning of a row */
+#define ZSTD_ROW_HASH_TAG_BITS 8 /* nb bits to use for the tag */
#define ZSTD_ROW_HASH_TAG_MASK ((1u << ZSTD_ROW_HASH_TAG_BITS) - 1)
+#define ZSTD_ROW_HASH_MAX_ENTRIES 64 /* absolute maximum number of entries per row, for all configurations */
#define ZSTD_ROW_HASH_CACHE_MASK (ZSTD_ROW_HASH_CACHE_SIZE - 1)
-typedef U32 ZSTD_VecMask; /* Clarifies when we are interacting with a U32 representing a mask of matches */
-
-#if !defined(ZSTD_NO_INTRINSICS) && defined(__SSE2__) /* SIMD SSE version */
-
-#include <emmintrin.h>
-typedef __m128i ZSTD_Vec128;
-
-/* Returns a 128-bit container with 128-bits from src */
-static ZSTD_Vec128 ZSTD_Vec128_read(const void* const src) {
- return _mm_loadu_si128((ZSTD_Vec128 const*)src);
-}
-
-/* Returns a ZSTD_Vec128 with the byte "val" packed 16 times */
-static ZSTD_Vec128 ZSTD_Vec128_set8(BYTE val) {
- return _mm_set1_epi8((char)val);
-}
-
-/* Do byte-by-byte comparison result of x and y. Then collapse 128-bit resultant mask
- * into a 32-bit mask that is the MSB of each byte.
- * */
-static ZSTD_VecMask ZSTD_Vec128_cmpMask8(ZSTD_Vec128 x, ZSTD_Vec128 y) {
- return (ZSTD_VecMask)_mm_movemask_epi8(_mm_cmpeq_epi8(x, y));
-}
-
-typedef struct {
- __m128i fst;
- __m128i snd;
-} ZSTD_Vec256;
-
-static ZSTD_Vec256 ZSTD_Vec256_read(const void* const ptr) {
- ZSTD_Vec256 v;
- v.fst = ZSTD_Vec128_read(ptr);
- v.snd = ZSTD_Vec128_read((ZSTD_Vec128 const*)ptr + 1);
- return v;
-}
-
-static ZSTD_Vec256 ZSTD_Vec256_set8(BYTE val) {
- ZSTD_Vec256 v;
- v.fst = ZSTD_Vec128_set8(val);
- v.snd = ZSTD_Vec128_set8(val);
- return v;
-}
-
-static ZSTD_VecMask ZSTD_Vec256_cmpMask8(ZSTD_Vec256 x, ZSTD_Vec256 y) {
- ZSTD_VecMask fstMask;
- ZSTD_VecMask sndMask;
- fstMask = ZSTD_Vec128_cmpMask8(x.fst, y.fst);
- sndMask = ZSTD_Vec128_cmpMask8(x.snd, y.snd);
- return fstMask | (sndMask << 16);
-}
-
-#elif !defined(ZSTD_NO_INTRINSICS) && defined(__ARM_NEON) /* SIMD ARM NEON Version */
-
-#include <arm_neon.h>
-typedef uint8x16_t ZSTD_Vec128;
-
-static ZSTD_Vec128 ZSTD_Vec128_read(const void* const src) {
- return vld1q_u8((const BYTE* const)src);
-}
-
-static ZSTD_Vec128 ZSTD_Vec128_set8(BYTE val) {
- return vdupq_n_u8(val);
-}
-
-/* Mimics '_mm_movemask_epi8()' from SSE */
-static U32 ZSTD_vmovmaskq_u8(ZSTD_Vec128 val) {
- /* Shift out everything but the MSB bits in each byte */
- uint16x8_t highBits = vreinterpretq_u16_u8(vshrq_n_u8(val, 7));
- /* Merge the even lanes together with vsra (right shift and add) */
- uint32x4_t paired16 = vreinterpretq_u32_u16(vsraq_n_u16(highBits, highBits, 7));
- uint64x2_t paired32 = vreinterpretq_u64_u32(vsraq_n_u32(paired16, paired16, 14));
- uint8x16_t paired64 = vreinterpretq_u8_u64(vsraq_n_u64(paired32, paired32, 28));
- /* Extract the low 8 bits from each lane, merge */
- return vgetq_lane_u8(paired64, 0) | ((U32)vgetq_lane_u8(paired64, 8) << 8);
-}
-
-static ZSTD_VecMask ZSTD_Vec128_cmpMask8(ZSTD_Vec128 x, ZSTD_Vec128 y) {
- return (ZSTD_VecMask)ZSTD_vmovmaskq_u8(vceqq_u8(x, y));
-}
-
-typedef struct {
- uint8x16_t fst;
- uint8x16_t snd;
-} ZSTD_Vec256;
-
-static ZSTD_Vec256 ZSTD_Vec256_read(const void* const ptr) {
- ZSTD_Vec256 v;
- v.fst = ZSTD_Vec128_read(ptr);
- v.snd = ZSTD_Vec128_read((ZSTD_Vec128 const*)ptr + 1);
- return v;
-}
-
-static ZSTD_Vec256 ZSTD_Vec256_set8(BYTE val) {
- ZSTD_Vec256 v;
- v.fst = ZSTD_Vec128_set8(val);
- v.snd = ZSTD_Vec128_set8(val);
- return v;
-}
-
-static ZSTD_VecMask ZSTD_Vec256_cmpMask8(ZSTD_Vec256 x, ZSTD_Vec256 y) {
- ZSTD_VecMask fstMask;
- ZSTD_VecMask sndMask;
- fstMask = ZSTD_Vec128_cmpMask8(x.fst, y.fst);
- sndMask = ZSTD_Vec128_cmpMask8(x.snd, y.snd);
- return fstMask | (sndMask << 16);
-}
-
-#else /* Scalar fallback version */
-
-#define VEC128_NB_SIZE_T (16 / sizeof(size_t))
-typedef struct {
- size_t vec[VEC128_NB_SIZE_T];
-} ZSTD_Vec128;
-
-static ZSTD_Vec128 ZSTD_Vec128_read(const void* const src) {
- ZSTD_Vec128 ret;
- ZSTD_memcpy(ret.vec, src, VEC128_NB_SIZE_T*sizeof(size_t));
- return ret;
-}
-
-static ZSTD_Vec128 ZSTD_Vec128_set8(BYTE val) {
- ZSTD_Vec128 ret = { {0} };
- int startBit = sizeof(size_t) * 8 - 8;
- for (;startBit >= 0; startBit -= 8) {
- unsigned j = 0;
- for (;j < VEC128_NB_SIZE_T; ++j) {
- ret.vec[j] |= ((size_t)val << startBit);
- }
- }
- return ret;
-}
-
-/* Compare x to y, byte by byte, generating a "matches" bitfield */
-static ZSTD_VecMask ZSTD_Vec128_cmpMask8(ZSTD_Vec128 x, ZSTD_Vec128 y) {
- ZSTD_VecMask res = 0;
- unsigned i = 0;
- unsigned l = 0;
- for (; i < VEC128_NB_SIZE_T; ++i) {
- const size_t cmp1 = x.vec[i];
- const size_t cmp2 = y.vec[i];
- unsigned j = 0;
- for (; j < sizeof(size_t); ++j, ++l) {
- if (((cmp1 >> j*8) & 0xFF) == ((cmp2 >> j*8) & 0xFF)) {
- res |= ((U32)1 << (j+i*sizeof(size_t)));
- }
- }
- }
- return res;
-}
-
-#define VEC256_NB_SIZE_T 2*VEC128_NB_SIZE_T
-typedef struct {
- size_t vec[VEC256_NB_SIZE_T];
-} ZSTD_Vec256;
-
-static ZSTD_Vec256 ZSTD_Vec256_read(const void* const src) {
- ZSTD_Vec256 ret;
- ZSTD_memcpy(ret.vec, src, VEC256_NB_SIZE_T*sizeof(size_t));
- return ret;
-}
-
-static ZSTD_Vec256 ZSTD_Vec256_set8(BYTE val) {
- ZSTD_Vec256 ret = { {0} };
- int startBit = sizeof(size_t) * 8 - 8;
- for (;startBit >= 0; startBit -= 8) {
- unsigned j = 0;
- for (;j < VEC256_NB_SIZE_T; ++j) {
- ret.vec[j] |= ((size_t)val << startBit);
- }
- }
- return ret;
-}
-
-/* Compare x to y, byte by byte, generating a "matches" bitfield */
-static ZSTD_VecMask ZSTD_Vec256_cmpMask8(ZSTD_Vec256 x, ZSTD_Vec256 y) {
- ZSTD_VecMask res = 0;
- unsigned i = 0;
- unsigned l = 0;
- for (; i < VEC256_NB_SIZE_T; ++i) {
- const size_t cmp1 = x.vec[i];
- const size_t cmp2 = y.vec[i];
- unsigned j = 0;
- for (; j < sizeof(size_t); ++j, ++l) {
- if (((cmp1 >> j*8) & 0xFF) == ((cmp2 >> j*8) & 0xFF)) {
- res |= ((U32)1 << (j+i*sizeof(size_t)));
- }
- }
- }
- return res;
-}
-
-#endif /* !defined(ZSTD_NO_INTRINSICS) && defined(__SSE2__) */
+typedef U64 ZSTD_VecMask; /* Clarifies when we are interacting with a U64 representing a mask of matches */
/* ZSTD_VecMask_next():
* Starting from the LSB, returns the idx of the next non-zero bit.
* Basically counting the nb of trailing zeroes.
*/
static U32 ZSTD_VecMask_next(ZSTD_VecMask val) {
-# if defined(_MSC_VER) /* Visual */
- unsigned long r=0;
- return _BitScanForward(&r, val) ? (U32)r : 0;
-# elif defined(__GNUC__) && (__GNUC__ >= 3)
- return (U32)__builtin_ctz(val);
+ assert(val != 0);
+# if defined(_MSC_VER) && defined(_WIN64)
+ if (val != 0) {
+ unsigned long r;
+ _BitScanForward64(&r, val);
+ return (U32)(r);
+ } else {
+ /* Should not reach this code path */
+ __assume(0);
+ }
+# elif (defined(__GNUC__) && ((__GNUC__ > 3) || ((__GNUC__ == 3) && (__GNUC_MINOR__ >= 4))))
+ if (sizeof(size_t) == 4) {
+ U32 mostSignificantWord = (U32)(val >> 32);
+ U32 leastSignificantWord = (U32)val;
+ if (leastSignificantWord == 0) {
+ return 32 + (U32)__builtin_ctz(mostSignificantWord);
+ } else {
+ return (U32)__builtin_ctz(leastSignificantWord);
+ }
+ } else {
+ return (U32)__builtin_ctzll(val);
+ }
# else
- /* Software ctz version: http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightMultLookup */
- static const U32 multiplyDeBruijnBitPosition[32] =
- {
- 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8,
- 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9
- };
- return multiplyDeBruijnBitPosition[((U32)((v & -(int)v) * 0x077CB531U)) >> 27];
+ /* Software ctz version: http://aggregate.org/MAGIC/#Trailing%20Zero%20Count
+ * and: https://stackoverflow.com/questions/2709430/count-number-of-bits-in-a-64-bit-long-big-integer
+ */
+ val = ~val & (val - 1ULL); /* Lowest set bit mask */
+ val = val - ((val >> 1) & 0x5555555555555555);
+ val = (val & 0x3333333333333333ULL) + ((val >> 2) & 0x3333333333333333ULL);
+ return (U32)((((val + (val >> 4)) & 0xF0F0F0F0F0F0F0FULL) * 0x101010101010101ULL) >> 56);
# endif
}
-/* ZSTD_VecMask_rotateRight():
- * Rotates a bitfield to the right by "rotation" bits.
- * If the rotation is greater than totalBits, the returned mask is 0.
+/* ZSTD_rotateRight_*():
+ * Rotates a bitfield to the right by "count" bits.
+ * https://en.wikipedia.org/w/index.php?title=Circular_shift&oldid=991635599#Implementing_circular_shifts
*/
-FORCE_INLINE_TEMPLATE ZSTD_VecMask
-ZSTD_VecMask_rotateRight(ZSTD_VecMask mask, U32 const rotation, U32 const totalBits) {
- if (rotation == 0)
- return mask;
- switch (totalBits) {
- default:
- assert(0);
- case 16:
- return (mask >> rotation) | (U16)(mask << (16 - rotation));
- case 32:
- return (mask >> rotation) | (U32)(mask << (32 - rotation));
- }
+FORCE_INLINE_TEMPLATE
+U64 ZSTD_rotateRight_U64(U64 const value, U32 count) {
+ assert(count < 64);
+ count &= 0x3F; /* for fickle pattern recognition */
+ return (value >> count) | (U64)(value << ((0U - count) & 0x3F));
+}
+
+FORCE_INLINE_TEMPLATE
+U32 ZSTD_rotateRight_U32(U32 const value, U32 count) {
+ assert(count < 32);
+ count &= 0x1F; /* for fickle pattern recognition */
+ return (value >> count) | (U32)(value << ((0U - count) & 0x1F));
+}
+
+FORCE_INLINE_TEMPLATE
+U16 ZSTD_rotateRight_U16(U16 const value, U32 count) {
+ assert(count < 16);
+ count &= 0x0F; /* for fickle pattern recognition */
+ return (value >> count) | (U16)(value << ((0U - count) & 0x0F));
}
/* ZSTD_row_nextIndex():
@@ -1126,20 +851,24 @@ MEM_STATIC int ZSTD_isAligned(void const* ptr, size_t align) {
*/
FORCE_INLINE_TEMPLATE void ZSTD_row_prefetch(U32 const* hashTable, U16 const* tagTable, U32 const relRow, U32 const rowLog) {
PREFETCH_L1(hashTable + relRow);
- if (rowLog == 5) {
+ if (rowLog >= 5) {
PREFETCH_L1(hashTable + relRow + 16);
+ /* Note: prefetching more of the hash table does not appear to be beneficial for 128-entry rows */
}
PREFETCH_L1(tagTable + relRow);
- assert(rowLog == 4 || rowLog == 5);
+ if (rowLog == 6) {
+ PREFETCH_L1(tagTable + relRow + 32);
+ }
+ assert(rowLog == 4 || rowLog == 5 || rowLog == 6);
assert(ZSTD_isAligned(hashTable + relRow, 64)); /* prefetched hash row always 64-byte aligned */
- assert(ZSTD_isAligned(tagTable + relRow, (size_t)1 << rowLog)); /* prefetched tagRow sits on a multiple of 32 or 64 bytes */
+ assert(ZSTD_isAligned(tagTable + relRow, (size_t)1 << rowLog)); /* prefetched tagRow sits on correct multiple of bytes (32,64,128) */
}
/* ZSTD_row_fillHashCache():
* Fill up the hash cache starting at idx, prefetching up to ZSTD_ROW_HASH_CACHE_SIZE entries,
* but not beyond iLimit.
*/
-static void ZSTD_row_fillHashCache(ZSTD_matchState_t* ms, const BYTE* base,
+FORCE_INLINE_TEMPLATE void ZSTD_row_fillHashCache(ZSTD_matchState_t* ms, const BYTE* base,
U32 const rowLog, U32 const mls,
U32 idx, const BYTE* const iLimit)
{
@@ -1179,35 +908,65 @@ FORCE_INLINE_TEMPLATE U32 ZSTD_row_nextCachedHash(U32* cache, U32 const* hashTab
}
}
-/* ZSTD_row_update_internal():
- * Inserts the byte at ip into the appropriate position in the hash table.
- * Determines the relative row, and the position within the {16, 32} entry row to insert at.
+/* ZSTD_row_update_internalImpl():
+ * Updates the hash table with positions starting from updateStartIdx until updateEndIdx.
*/
-FORCE_INLINE_TEMPLATE void ZSTD_row_update_internal(ZSTD_matchState_t* ms, const BYTE* ip,
- U32 const mls, U32 const rowLog,
- U32 const rowMask, U32 const useCache)
+FORCE_INLINE_TEMPLATE void ZSTD_row_update_internalImpl(ZSTD_matchState_t* ms,
+ U32 updateStartIdx, U32 const updateEndIdx,
+ U32 const mls, U32 const rowLog,
+ U32 const rowMask, U32 const useCache)
{
U32* const hashTable = ms->hashTable;
U16* const tagTable = ms->tagTable;
U32 const hashLog = ms->rowHashLog;
const BYTE* const base = ms->window.base;
- const U32 target = (U32)(ip - base);
- U32 idx = ms->nextToUpdate;
- DEBUGLOG(6, "ZSTD_row_update_internal(): nextToUpdate=%u, current=%u", idx, target);
- for (; idx < target; ++idx) {
- U32 const hash = useCache ? ZSTD_row_nextCachedHash(ms->hashCache, hashTable, tagTable, base, idx, hashLog, rowLog, mls)
- : (U32)ZSTD_hashPtr(base + idx, hashLog + ZSTD_ROW_HASH_TAG_BITS, mls);
+ DEBUGLOG(6, "ZSTD_row_update_internalImpl(): updateStartIdx=%u, updateEndIdx=%u", updateStartIdx, updateEndIdx);
+ for (; updateStartIdx < updateEndIdx; ++updateStartIdx) {
+ U32 const hash = useCache ? ZSTD_row_nextCachedHash(ms->hashCache, hashTable, tagTable, base, updateStartIdx, hashLog, rowLog, mls)
+ : (U32)ZSTD_hashPtr(base + updateStartIdx, hashLog + ZSTD_ROW_HASH_TAG_BITS, mls);
U32 const relRow = (hash >> ZSTD_ROW_HASH_TAG_BITS) << rowLog;
U32* const row = hashTable + relRow;
BYTE* tagRow = (BYTE*)(tagTable + relRow); /* Though tagTable is laid out as a table of U16, each tag is only 1 byte.
Explicit cast allows us to get exact desired position within each row */
U32 const pos = ZSTD_row_nextIndex(tagRow, rowMask);
- assert(hash == ZSTD_hashPtr(base + idx, hashLog + ZSTD_ROW_HASH_TAG_BITS, mls));
+ assert(hash == ZSTD_hashPtr(base + updateStartIdx, hashLog + ZSTD_ROW_HASH_TAG_BITS, mls));
((BYTE*)tagRow)[pos + ZSTD_ROW_HASH_TAG_OFFSET] = hash & ZSTD_ROW_HASH_TAG_MASK;
- row[pos] = idx;
+ row[pos] = updateStartIdx;
}
+}
+
+/* ZSTD_row_update_internal():
+ * Inserts the byte at ip into the appropriate position in the hash table, and updates ms->nextToUpdate.
+ * Skips sections of long matches as is necessary.
+ */
+FORCE_INLINE_TEMPLATE void ZSTD_row_update_internal(ZSTD_matchState_t* ms, const BYTE* ip,
+ U32 const mls, U32 const rowLog,
+ U32 const rowMask, U32 const useCache)
+{
+ U32 idx = ms->nextToUpdate;
+ const BYTE* const base = ms->window.base;
+ const U32 target = (U32)(ip - base);
+ const U32 kSkipThreshold = 384;
+ const U32 kMaxMatchStartPositionsToUpdate = 96;
+ const U32 kMaxMatchEndPositionsToUpdate = 32;
+
+ if (useCache) {
+ /* Only skip positions when using hash cache, i.e.
+ * if we are loading a dict, don't skip anything.
+ * If we decide to skip, then we only update a set number
+ * of positions at the beginning and end of the match.
+ */
+ if (UNLIKELY(target - idx > kSkipThreshold)) {
+ U32 const bound = idx + kMaxMatchStartPositionsToUpdate;
+ ZSTD_row_update_internalImpl(ms, idx, bound, mls, rowLog, rowMask, useCache);
+ idx = target - kMaxMatchEndPositionsToUpdate;
+ ZSTD_row_fillHashCache(ms, base, rowLog, mls, idx, ip+1);
+ }
+ }
+ assert(target >= idx);
+ ZSTD_row_update_internalImpl(ms, idx, target, mls, rowLog, rowMask, useCache);
ms->nextToUpdate = target;
}
@@ -1216,7 +975,7 @@ FORCE_INLINE_TEMPLATE void ZSTD_row_update_internal(ZSTD_matchState_t* ms, const
* processing.
*/
void ZSTD_row_update(ZSTD_matchState_t* const ms, const BYTE* ip) {
- const U32 rowLog = ms->cParams.searchLog < 5 ? 4 : 5;
+ const U32 rowLog = BOUNDED(4, ms->cParams.searchLog, 6);
const U32 rowMask = (1u << rowLog) - 1;
const U32 mls = MIN(ms->cParams.minMatch, 6 /* mls caps out at 6 */);
@@ -1224,26 +983,131 @@ void ZSTD_row_update(ZSTD_matchState_t* const ms, const BYTE* ip) {
ZSTD_row_update_internal(ms, ip, mls, rowLog, rowMask, 0 /* dont use cache */);
}
+#if defined(ZSTD_ARCH_X86_SSE2)
+FORCE_INLINE_TEMPLATE ZSTD_VecMask
+ZSTD_row_getSSEMask(int nbChunks, const BYTE* const src, const BYTE tag, const U32 head)
+{
+ const __m128i comparisonMask = _mm_set1_epi8((char)tag);
+ int matches[4] = {0};
+ int i;
+ assert(nbChunks == 1 || nbChunks == 2 || nbChunks == 4);
+ for (i=0; i<nbChunks; i++) {
+ const __m128i chunk = _mm_loadu_si128((const __m128i*)(const void*)(src + 16*i));
+ const __m128i equalMask = _mm_cmpeq_epi8(chunk, comparisonMask);
+ matches[i] = _mm_movemask_epi8(equalMask);
+ }
+ if (nbChunks == 1) return ZSTD_rotateRight_U16((U16)matches[0], head);
+ if (nbChunks == 2) return ZSTD_rotateRight_U32((U32)matches[1] << 16 | (U32)matches[0], head);
+ assert(nbChunks == 4);
+ return ZSTD_rotateRight_U64((U64)matches[3] << 48 | (U64)matches[2] << 32 | (U64)matches[1] << 16 | (U64)matches[0], head);
+}
+#endif
+
/* Returns a ZSTD_VecMask (U32) that has the nth bit set to 1 if the newly-computed "tag" matches
* the hash at the nth position in a row of the tagTable.
- */
-FORCE_INLINE_TEMPLATE
-ZSTD_VecMask ZSTD_row_getMatchMask(const BYTE* const tagRow, const BYTE tag, const U32 head, const U32 rowEntries) {
- ZSTD_VecMask matches = 0;
- if (rowEntries == 16) {
- ZSTD_Vec128 hashes = ZSTD_Vec128_read(tagRow + ZSTD_ROW_HASH_TAG_OFFSET);
- ZSTD_Vec128 expandedTags = ZSTD_Vec128_set8(tag);
- matches = ZSTD_Vec128_cmpMask8(hashes, expandedTags);
- } else if (rowEntries == 32) {
- ZSTD_Vec256 hashes = ZSTD_Vec256_read(tagRow + ZSTD_ROW_HASH_TAG_OFFSET);
- ZSTD_Vec256 expandedTags = ZSTD_Vec256_set8(tag);
- matches = ZSTD_Vec256_cmpMask8(hashes, expandedTags);
- } else {
- assert(0);
+ * Each row is a circular buffer beginning at the value of "head". So we must rotate the "matches" bitfield
+ * to match up with the actual layout of the entries within the hashTable */
+FORCE_INLINE_TEMPLATE ZSTD_VecMask
+ZSTD_row_getMatchMask(const BYTE* const tagRow, const BYTE tag, const U32 head, const U32 rowEntries)
+{
+ const BYTE* const src = tagRow + ZSTD_ROW_HASH_TAG_OFFSET;
+ assert((rowEntries == 16) || (rowEntries == 32) || rowEntries == 64);
+ assert(rowEntries <= ZSTD_ROW_HASH_MAX_ENTRIES);
+
+#if defined(ZSTD_ARCH_X86_SSE2)
+
+ return ZSTD_row_getSSEMask(rowEntries / 16, src, tag, head);
+
+#else /* SW or NEON-LE */
+
+# if defined(ZSTD_ARCH_ARM_NEON)
+ /* This NEON path only works for little endian - otherwise use SWAR below */
+ if (MEM_isLittleEndian()) {
+ if (rowEntries == 16) {
+ const uint8x16_t chunk = vld1q_u8(src);
+ const uint16x8_t equalMask = vreinterpretq_u16_u8(vceqq_u8(chunk, vdupq_n_u8(tag)));
+ const uint16x8_t t0 = vshlq_n_u16(equalMask, 7);
+ const uint32x4_t t1 = vreinterpretq_u32_u16(vsriq_n_u16(t0, t0, 14));
+ const uint64x2_t t2 = vreinterpretq_u64_u32(vshrq_n_u32(t1, 14));
+ const uint8x16_t t3 = vreinterpretq_u8_u64(vsraq_n_u64(t2, t2, 28));
+ const U16 hi = (U16)vgetq_lane_u8(t3, 8);
+ const U16 lo = (U16)vgetq_lane_u8(t3, 0);
+ return ZSTD_rotateRight_U16((hi << 8) | lo, head);
+ } else if (rowEntries == 32) {
+ const uint16x8x2_t chunk = vld2q_u16((const U16*)(const void*)src);
+ const uint8x16_t chunk0 = vreinterpretq_u8_u16(chunk.val[0]);
+ const uint8x16_t chunk1 = vreinterpretq_u8_u16(chunk.val[1]);
+ const uint8x16_t equalMask0 = vceqq_u8(chunk0, vdupq_n_u8(tag));
+ const uint8x16_t equalMask1 = vceqq_u8(chunk1, vdupq_n_u8(tag));
+ const int8x8_t pack0 = vqmovn_s16(vreinterpretq_s16_u8(equalMask0));
+ const int8x8_t pack1 = vqmovn_s16(vreinterpretq_s16_u8(equalMask1));
+ const uint8x8_t t0 = vreinterpret_u8_s8(pack0);
+ const uint8x8_t t1 = vreinterpret_u8_s8(pack1);
+ const uint8x8_t t2 = vsri_n_u8(t1, t0, 2);
+ const uint8x8x2_t t3 = vuzp_u8(t2, t0);
+ const uint8x8_t t4 = vsri_n_u8(t3.val[1], t3.val[0], 4);
+ const U32 matches = vget_lane_u32(vreinterpret_u32_u8(t4), 0);
+ return ZSTD_rotateRight_U32(matches, head);
+ } else { /* rowEntries == 64 */
+ const uint8x16x4_t chunk = vld4q_u8(src);
+ const uint8x16_t dup = vdupq_n_u8(tag);
+ const uint8x16_t cmp0 = vceqq_u8(chunk.val[0], dup);
+ const uint8x16_t cmp1 = vceqq_u8(chunk.val[1], dup);
+ const uint8x16_t cmp2 = vceqq_u8(chunk.val[2], dup);
+ const uint8x16_t cmp3 = vceqq_u8(chunk.val[3], dup);
+
+ const uint8x16_t t0 = vsriq_n_u8(cmp1, cmp0, 1);
+ const uint8x16_t t1 = vsriq_n_u8(cmp3, cmp2, 1);
+ const uint8x16_t t2 = vsriq_n_u8(t1, t0, 2);
+ const uint8x16_t t3 = vsriq_n_u8(t2, t2, 4);
+ const uint8x8_t t4 = vshrn_n_u16(vreinterpretq_u16_u8(t3), 4);
+ const U64 matches = vget_lane_u64(vreinterpret_u64_u8(t4), 0);
+ return ZSTD_rotateRight_U64(matches, head);
+ }
}
- /* Each row is a circular buffer beginning at the value of "head". So we must rotate the "matches" bitfield
- to match up with the actual layout of the entries within the hashTable */
- return ZSTD_VecMask_rotateRight(matches, head, rowEntries);
+# endif /* ZSTD_ARCH_ARM_NEON */
+ /* SWAR */
+ { const size_t chunkSize = sizeof(size_t);
+ const size_t shiftAmount = ((chunkSize * 8) - chunkSize);
+ const size_t xFF = ~((size_t)0);
+ const size_t x01 = xFF / 0xFF;
+ const size_t x80 = x01 << 7;
+ const size_t splatChar = tag * x01;
+ ZSTD_VecMask matches = 0;
+ int i = rowEntries - chunkSize;
+ assert((sizeof(size_t) == 4) || (sizeof(size_t) == 8));
+ if (MEM_isLittleEndian()) { /* runtime check so have two loops */
+ const size_t extractMagic = (xFF / 0x7F) >> chunkSize;
+ do {
+ size_t chunk = MEM_readST(&src[i]);
+ chunk ^= splatChar;
+ chunk = (((chunk | x80) - x01) | chunk) & x80;
+ matches <<= chunkSize;
+ matches |= (chunk * extractMagic) >> shiftAmount;
+ i -= chunkSize;
+ } while (i >= 0);
+ } else { /* big endian: reverse bits during extraction */
+ const size_t msb = xFF ^ (xFF >> 1);
+ const size_t extractMagic = (msb / 0x1FF) | msb;
+ do {
+ size_t chunk = MEM_readST(&src[i]);
+ chunk ^= splatChar;
+ chunk = (((chunk | x80) - x01) | chunk) & x80;
+ matches <<= chunkSize;
+ matches |= ((chunk >> 7) * extractMagic) >> shiftAmount;
+ i -= chunkSize;
+ } while (i >= 0);
+ }
+ matches = ~matches;
+ if (rowEntries == 16) {
+ return ZSTD_rotateRight_U16((U16)matches, head);
+ } else if (rowEntries == 32) {
+ return ZSTD_rotateRight_U32((U32)matches, head);
+ } else {
+ return ZSTD_rotateRight_U64((U64)matches, head);
+ }
+ }
+#endif
}
/* The high-level approach of the SIMD row based match finder is as follows:
@@ -1262,7 +1126,7 @@ ZSTD_VecMask ZSTD_row_getMatchMask(const BYTE* const tagRow, const BYTE tag, con
* - Pick the longest match.
*/
FORCE_INLINE_TEMPLATE
-size_t ZSTD_RowFindBestMatch_generic (
+size_t ZSTD_RowFindBestMatch(
ZSTD_matchState_t* ms,
const BYTE* const ip, const BYTE* const iLimit,
size_t* offsetPtr,
@@ -1293,11 +1157,13 @@ size_t ZSTD_RowFindBestMatch_generic (
/* DMS/DDS variables that may be referenced laster */
const ZSTD_matchState_t* const dms = ms->dictMatchState;
- size_t ddsIdx;
- U32 ddsExtraAttempts; /* cctx hash tables are limited in searches, but allow extra searches into DDS */
- U32 dmsTag;
- U32* dmsRow;
- BYTE* dmsTagRow;
+
+ /* Initialize the following variables to satisfy static analyzer */
+ size_t ddsIdx = 0;
+ U32 ddsExtraAttempts = 0; /* cctx hash tables are limited in searches, but allow extra searches into DDS */
+ U32 dmsTag = 0;
+ U32* dmsRow = NULL;
+ BYTE* dmsTagRow = NULL;
if (dictMode == ZSTD_dedicatedDictSearch) {
const U32 ddsHashLog = dms->cParams.hashLog - ZSTD_LAZY_DDSS_BUCKET_LOG;
@@ -1329,7 +1195,7 @@ size_t ZSTD_RowFindBestMatch_generic (
U32* const row = hashTable + relRow;
BYTE* tagRow = (BYTE*)(tagTable + relRow);
U32 const head = *tagRow & rowMask;
- U32 matchBuffer[32 /* maximum nb entries per row */];
+ U32 matchBuffer[ZSTD_ROW_HASH_MAX_ENTRIES];
size_t numMatches = 0;
size_t currMatch = 0;
ZSTD_VecMask matches = ZSTD_row_getMatchMask(tagRow, (BYTE)tag, head, rowEntries);
@@ -1379,12 +1245,13 @@ size_t ZSTD_RowFindBestMatch_generic (
/* Save best solution */
if (currentMl > ml) {
ml = currentMl;
- *offsetPtr = curr - matchIndex + ZSTD_REP_MOVE;
+ *offsetPtr = STORE_OFFSET(curr - matchIndex);
if (ip+currentMl == iLimit) break; /* best possible, avoids read overflow on next attempt */
}
}
}
+ assert(nbAttempts <= (1U << ZSTD_SEARCHLOG_MAX)); /* Check we haven't underflowed. */
if (dictMode == ZSTD_dedicatedDictSearch) {
ml = ZSTD_dedicatedDictSearch_lazy_search(offsetPtr, ml, nbAttempts + ddsExtraAttempts, dms,
ip, iLimit, prefixStart, curr, dictLimit, ddsIdx);
@@ -1397,7 +1264,7 @@ size_t ZSTD_RowFindBestMatch_generic (
const U32 dmsIndexDelta = dictLimit - dmsSize;
{ U32 const head = *dmsTagRow & rowMask;
- U32 matchBuffer[32 /* maximum nb row entries */];
+ U32 matchBuffer[ZSTD_ROW_HASH_MAX_ENTRIES];
size_t numMatches = 0;
size_t currMatch = 0;
ZSTD_VecMask matches = ZSTD_row_getMatchMask(dmsTagRow, (BYTE)dmsTag, head, rowEntries);
@@ -1426,7 +1293,8 @@ size_t ZSTD_RowFindBestMatch_generic (
if (currentMl > ml) {
ml = currentMl;
- *offsetPtr = curr - (matchIndex + dmsIndexDelta) + ZSTD_REP_MOVE;
+ assert(curr > matchIndex + dmsIndexDelta);
+ *offsetPtr = STORE_OFFSET(curr - (matchIndex + dmsIndexDelta));
if (ip+currentMl == iLimit) break;
}
}
@@ -1435,84 +1303,175 @@ size_t ZSTD_RowFindBestMatch_generic (
return ml;
}
-/* Inlining is important to hardwire a hot branch (template emulation) */
-FORCE_INLINE_TEMPLATE size_t ZSTD_RowFindBestMatch_selectMLS (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- const ZSTD_dictMode_e dictMode, size_t* offsetPtr, const U32 rowLog)
-{
- switch(ms->cParams.minMatch)
- {
- default : /* includes case 3 */
- case 4 : return ZSTD_RowFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 4, dictMode, rowLog);
- case 5 : return ZSTD_RowFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 5, dictMode, rowLog);
- case 7 :
- case 6 : return ZSTD_RowFindBestMatch_generic(ms, ip, iLimit, offsetPtr, 6, dictMode, rowLog);
- }
-}
-FORCE_INLINE_TEMPLATE size_t ZSTD_RowFindBestMatch_selectRowLog (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- const U32 cappedSearchLog = MIN(ms->cParams.searchLog, 5);
- switch(cappedSearchLog)
- {
- default :
- case 4 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_noDict, offsetPtr, 4);
- case 5 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_noDict, offsetPtr, 5);
+typedef size_t (*searchMax_f)(
+ ZSTD_matchState_t* ms,
+ const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
+
+/**
+ * This struct contains the functions necessary for lazy to search.
+ * Currently, that is only searchMax. However, it is still valuable to have the
+ * VTable because this makes it easier to add more functions to the VTable later.
+ *
+ * TODO: The start of the search function involves loading and calculating a
+ * bunch of constants from the ZSTD_matchState_t. These computations could be
+ * done in an initialization function, and saved somewhere in the match state.
+ * Then we could pass a pointer to the saved state instead of the match state,
+ * and avoid duplicate computations.
+ *
+ * TODO: Move the match re-winding into searchMax. This improves compression
+ * ratio, and unlocks further simplifications with the next TODO.
+ *
+ * TODO: Try moving the repcode search into searchMax. After the re-winding
+ * and repcode search are in searchMax, there is no more logic in the match
+ * finder loop that requires knowledge about the dictMode. So we should be
+ * able to avoid force inlining it, and we can join the extDict loop with
+ * the single segment loop. It should go in searchMax instead of its own
+ * function to avoid having multiple virtual function calls per search.
+ */
+typedef struct {
+ searchMax_f searchMax;
+} ZSTD_LazyVTable;
+
+#define GEN_ZSTD_BT_VTABLE(dictMode, mls) \
+ static size_t ZSTD_BtFindBestMatch_##dictMode##_##mls( \
+ ZSTD_matchState_t* ms, \
+ const BYTE* ip, const BYTE* const iLimit, \
+ size_t* offsetPtr) \
+ { \
+ assert(MAX(4, MIN(6, ms->cParams.minMatch)) == mls); \
+ return ZSTD_BtFindBestMatch(ms, ip, iLimit, offsetPtr, mls, ZSTD_##dictMode); \
+ } \
+ static const ZSTD_LazyVTable ZSTD_BtVTable_##dictMode##_##mls = { \
+ ZSTD_BtFindBestMatch_##dictMode##_##mls \
+ };
+
+#define GEN_ZSTD_HC_VTABLE(dictMode, mls) \
+ static size_t ZSTD_HcFindBestMatch_##dictMode##_##mls( \
+ ZSTD_matchState_t* ms, \
+ const BYTE* ip, const BYTE* const iLimit, \
+ size_t* offsetPtr) \
+ { \
+ assert(MAX(4, MIN(6, ms->cParams.minMatch)) == mls); \
+ return ZSTD_HcFindBestMatch(ms, ip, iLimit, offsetPtr, mls, ZSTD_##dictMode); \
+ } \
+ static const ZSTD_LazyVTable ZSTD_HcVTable_##dictMode##_##mls = { \
+ ZSTD_HcFindBestMatch_##dictMode##_##mls \
+ };
+
+#define GEN_ZSTD_ROW_VTABLE(dictMode, mls, rowLog) \
+ static size_t ZSTD_RowFindBestMatch_##dictMode##_##mls##_##rowLog( \
+ ZSTD_matchState_t* ms, \
+ const BYTE* ip, const BYTE* const iLimit, \
+ size_t* offsetPtr) \
+ { \
+ assert(MAX(4, MIN(6, ms->cParams.minMatch)) == mls); \
+ assert(MAX(4, MIN(6, ms->cParams.searchLog)) == rowLog); \
+ return ZSTD_RowFindBestMatch(ms, ip, iLimit, offsetPtr, mls, ZSTD_##dictMode, rowLog); \
+ } \
+ static const ZSTD_LazyVTable ZSTD_RowVTable_##dictMode##_##mls##_##rowLog = { \
+ ZSTD_RowFindBestMatch_##dictMode##_##mls##_##rowLog \
+ };
+
+#define ZSTD_FOR_EACH_ROWLOG(X, dictMode, mls) \
+ X(dictMode, mls, 4) \
+ X(dictMode, mls, 5) \
+ X(dictMode, mls, 6)
+
+#define ZSTD_FOR_EACH_MLS_ROWLOG(X, dictMode) \
+ ZSTD_FOR_EACH_ROWLOG(X, dictMode, 4) \
+ ZSTD_FOR_EACH_ROWLOG(X, dictMode, 5) \
+ ZSTD_FOR_EACH_ROWLOG(X, dictMode, 6)
+
+#define ZSTD_FOR_EACH_MLS(X, dictMode) \
+ X(dictMode, 4) \
+ X(dictMode, 5) \
+ X(dictMode, 6)
+
+#define ZSTD_FOR_EACH_DICT_MODE(X, ...) \
+ X(__VA_ARGS__, noDict) \
+ X(__VA_ARGS__, extDict) \
+ X(__VA_ARGS__, dictMatchState) \
+ X(__VA_ARGS__, dedicatedDictSearch)
+
+/* Generate Row VTables for each combination of (dictMode, mls, rowLog) */
+ZSTD_FOR_EACH_DICT_MODE(ZSTD_FOR_EACH_MLS_ROWLOG, GEN_ZSTD_ROW_VTABLE)
+/* Generate Binary Tree VTables for each combination of (dictMode, mls) */
+ZSTD_FOR_EACH_DICT_MODE(ZSTD_FOR_EACH_MLS, GEN_ZSTD_BT_VTABLE)
+/* Generate Hash Chain VTables for each combination of (dictMode, mls) */
+ZSTD_FOR_EACH_DICT_MODE(ZSTD_FOR_EACH_MLS, GEN_ZSTD_HC_VTABLE)
+
+#define GEN_ZSTD_BT_VTABLE_ARRAY(dictMode) \
+ { \
+ &ZSTD_BtVTable_##dictMode##_4, \
+ &ZSTD_BtVTable_##dictMode##_5, \
+ &ZSTD_BtVTable_##dictMode##_6 \
}
-}
-FORCE_INLINE_TEMPLATE size_t ZSTD_RowFindBestMatch_dictMatchState_selectRowLog(
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- const U32 cappedSearchLog = MIN(ms->cParams.searchLog, 5);
- switch(cappedSearchLog)
- {
- default :
- case 4 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_dictMatchState, offsetPtr, 4);
- case 5 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_dictMatchState, offsetPtr, 5);
+#define GEN_ZSTD_HC_VTABLE_ARRAY(dictMode) \
+ { \
+ &ZSTD_HcVTable_##dictMode##_4, \
+ &ZSTD_HcVTable_##dictMode##_5, \
+ &ZSTD_HcVTable_##dictMode##_6 \
}
-}
-FORCE_INLINE_TEMPLATE size_t ZSTD_RowFindBestMatch_dedicatedDictSearch_selectRowLog(
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- const U32 cappedSearchLog = MIN(ms->cParams.searchLog, 5);
- switch(cappedSearchLog)
- {
- default :
- case 4 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_dedicatedDictSearch, offsetPtr, 4);
- case 5 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_dedicatedDictSearch, offsetPtr, 5);
+#define GEN_ZSTD_ROW_VTABLE_ARRAY_(dictMode, mls) \
+ { \
+ &ZSTD_RowVTable_##dictMode##_##mls##_4, \
+ &ZSTD_RowVTable_##dictMode##_##mls##_5, \
+ &ZSTD_RowVTable_##dictMode##_##mls##_6 \
}
-}
-FORCE_INLINE_TEMPLATE size_t ZSTD_RowFindBestMatch_extDict_selectRowLog (
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* const iLimit,
- size_t* offsetPtr)
-{
- const U32 cappedSearchLog = MIN(ms->cParams.searchLog, 5);
- switch(cappedSearchLog)
- {
- default :
- case 4 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_extDict, offsetPtr, 4);
- case 5 : return ZSTD_RowFindBestMatch_selectMLS(ms, ip, iLimit, ZSTD_extDict, offsetPtr, 5);
+#define GEN_ZSTD_ROW_VTABLE_ARRAY(dictMode) \
+ { \
+ GEN_ZSTD_ROW_VTABLE_ARRAY_(dictMode, 4), \
+ GEN_ZSTD_ROW_VTABLE_ARRAY_(dictMode, 5), \
+ GEN_ZSTD_ROW_VTABLE_ARRAY_(dictMode, 6) \
}
-}
+#define GEN_ZSTD_VTABLE_ARRAY(X) \
+ { \
+ X(noDict), \
+ X(extDict), \
+ X(dictMatchState), \
+ X(dedicatedDictSearch) \
+ }
/* *******************************
* Common parser - lazy strategy
*********************************/
typedef enum { search_hashChain=0, search_binaryTree=1, search_rowHash=2 } searchMethod_e;
+/**
+ * This table is indexed first by the four ZSTD_dictMode_e values, and then
+ * by the two searchMethod_e values. NULLs are placed for configurations
+ * that should never occur (extDict modes go to the other implementation
+ * below and there is no DDSS for binary tree search yet).
+ */
+
+static ZSTD_LazyVTable const*
+ZSTD_selectLazyVTable(ZSTD_matchState_t const* ms, searchMethod_e searchMethod, ZSTD_dictMode_e dictMode)
+{
+ /* Fill the Hc/Bt VTable arrays with the right functions for the (dictMode, mls) combination. */
+ ZSTD_LazyVTable const* const hcVTables[4][3] = GEN_ZSTD_VTABLE_ARRAY(GEN_ZSTD_HC_VTABLE_ARRAY);
+ ZSTD_LazyVTable const* const btVTables[4][3] = GEN_ZSTD_VTABLE_ARRAY(GEN_ZSTD_BT_VTABLE_ARRAY);
+ /* Fill the Row VTable array with the right functions for the (dictMode, mls, rowLog) combination. */
+ ZSTD_LazyVTable const* const rowVTables[4][3][3] = GEN_ZSTD_VTABLE_ARRAY(GEN_ZSTD_ROW_VTABLE_ARRAY);
+
+ U32 const mls = MAX(4, MIN(6, ms->cParams.minMatch));
+ U32 const rowLog = MAX(4, MIN(6, ms->cParams.searchLog));
+ switch (searchMethod) {
+ case search_hashChain:
+ return hcVTables[dictMode][mls - 4];
+ case search_binaryTree:
+ return btVTables[dictMode][mls - 4];
+ case search_rowHash:
+ return rowVTables[dictMode][mls - 4][rowLog - 4];
+ default:
+ return NULL;
+ }
+}
+
FORCE_INLINE_TEMPLATE size_t
ZSTD_compressBlock_lazy_generic(
ZSTD_matchState_t* ms, seqStore_t* seqStore,
@@ -1525,46 +1484,12 @@ ZSTD_compressBlock_lazy_generic(
const BYTE* ip = istart;
const BYTE* anchor = istart;
const BYTE* const iend = istart + srcSize;
- const BYTE* const ilimit = searchMethod == search_rowHash ? iend - 8 - ZSTD_ROW_HASH_CACHE_SIZE : iend - 8;
+ const BYTE* const ilimit = (searchMethod == search_rowHash) ? iend - 8 - ZSTD_ROW_HASH_CACHE_SIZE : iend - 8;
const BYTE* const base = ms->window.base;
const U32 prefixLowestIndex = ms->window.dictLimit;
const BYTE* const prefixLowest = base + prefixLowestIndex;
- const U32 rowLog = ms->cParams.searchLog < 5 ? 4 : 5;
- typedef size_t (*searchMax_f)(
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
-
- /**
- * This table is indexed first by the four ZSTD_dictMode_e values, and then
- * by the two searchMethod_e values. NULLs are placed for configurations
- * that should never occur (extDict modes go to the other implementation
- * below and there is no DDSS for binary tree search yet).
- */
- const searchMax_f searchFuncs[4][3] = {
- {
- ZSTD_HcFindBestMatch_selectMLS,
- ZSTD_BtFindBestMatch_selectMLS,
- ZSTD_RowFindBestMatch_selectRowLog
- },
- {
- NULL,
- NULL,
- NULL
- },
- {
- ZSTD_HcFindBestMatch_dictMatchState_selectMLS,
- ZSTD_BtFindBestMatch_dictMatchState_selectMLS,
- ZSTD_RowFindBestMatch_dictMatchState_selectRowLog
- },
- {
- ZSTD_HcFindBestMatch_dedicatedDictSearch_selectMLS,
- NULL,
- ZSTD_RowFindBestMatch_dedicatedDictSearch_selectRowLog
- }
- };
-
- searchMax_f const searchMax = searchFuncs[dictMode][(int)searchMethod];
+ searchMax_f const searchMax = ZSTD_selectLazyVTable(ms, searchMethod, dictMode)->searchMax;
U32 offset_1 = rep[0], offset_2 = rep[1], savedOffset=0;
const int isDMS = dictMode == ZSTD_dictMatchState;
@@ -1599,6 +1524,7 @@ ZSTD_compressBlock_lazy_generic(
}
if (searchMethod == search_rowHash) {
+ const U32 rowLog = MAX(4, MIN(6, ms->cParams.searchLog));
ZSTD_row_fillHashCache(ms, base, rowLog,
MIN(ms->cParams.minMatch, 6 /* mls caps out at 6 */),
ms->nextToUpdate, ilimit);
@@ -1613,8 +1539,9 @@ ZSTD_compressBlock_lazy_generic(
#endif
while (ip < ilimit) {
size_t matchLength=0;
- size_t offset=0;
+ size_t offcode=STORE_REPCODE_1;
const BYTE* start=ip+1;
+ DEBUGLOG(7, "search baseline (depth 0)");
/* check repCode */
if (isDxS) {
@@ -1640,7 +1567,7 @@ ZSTD_compressBlock_lazy_generic(
{ size_t offsetFound = 999999999;
size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
if (ml2 > matchLength)
- matchLength = ml2, start = ip, offset=offsetFound;
+ matchLength = ml2, start = ip, offcode=offsetFound;
}
if (matchLength < 4) {
@@ -1651,14 +1578,15 @@ ZSTD_compressBlock_lazy_generic(
/* let's try to find a better solution */
if (depth>=1)
while (ip<ilimit) {
+ DEBUGLOG(7, "search depth 1");
ip ++;
if ( (dictMode == ZSTD_noDict)
- && (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
+ && (offcode) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(mlRep * 3);
- int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
+ int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
- matchLength = mlRep, offset = 0, start = ip;
+ matchLength = mlRep, offcode = STORE_REPCODE_1, start = ip;
}
if (isDxS) {
const U32 repIndex = (U32)(ip - base) - offset_1;
@@ -1670,30 +1598,31 @@ ZSTD_compressBlock_lazy_generic(
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
int const gain2 = (int)(mlRep * 3);
- int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
+ int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
- matchLength = mlRep, offset = 0, start = ip;
+ matchLength = mlRep, offcode = STORE_REPCODE_1, start = ip;
}
}
{ size_t offset2=999999999;
size_t const ml2 = searchMax(ms, ip, iend, &offset2);
- int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
+ int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offset2))); /* raw approx */
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 4);
if ((ml2 >= 4) && (gain2 > gain1)) {
- matchLength = ml2, offset = offset2, start = ip;
+ matchLength = ml2, offcode = offset2, start = ip;
continue; /* search a better one */
} }
/* let's find an even better one */
if ((depth==2) && (ip<ilimit)) {
+ DEBUGLOG(7, "search depth 2");
ip ++;
if ( (dictMode == ZSTD_noDict)
- && (offset) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
+ && (offcode) && ((offset_1>0) & (MEM_read32(ip) == MEM_read32(ip - offset_1)))) {
size_t const mlRep = ZSTD_count(ip+4, ip+4-offset_1, iend) + 4;
int const gain2 = (int)(mlRep * 4);
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
- matchLength = mlRep, offset = 0, start = ip;
+ matchLength = mlRep, offcode = STORE_REPCODE_1, start = ip;
}
if (isDxS) {
const U32 repIndex = (U32)(ip - base) - offset_1;
@@ -1705,46 +1634,45 @@ ZSTD_compressBlock_lazy_generic(
const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
size_t const mlRep = ZSTD_count_2segments(ip+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
int const gain2 = (int)(mlRep * 4);
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 1);
if ((mlRep >= 4) && (gain2 > gain1))
- matchLength = mlRep, offset = 0, start = ip;
+ matchLength = mlRep, offcode = STORE_REPCODE_1, start = ip;
}
}
{ size_t offset2=999999999;
size_t const ml2 = searchMax(ms, ip, iend, &offset2);
- int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
+ int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offset2))); /* raw approx */
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 7);
if ((ml2 >= 4) && (gain2 > gain1)) {
- matchLength = ml2, offset = offset2, start = ip;
+ matchLength = ml2, offcode = offset2, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
}
/* NOTE:
- * start[-offset+ZSTD_REP_MOVE-1] is undefined behavior.
- * (-offset+ZSTD_REP_MOVE-1) is unsigned, and is added to start, which
- * overflows the pointer, which is undefined behavior.
+ * Pay attention that `start[-value]` can lead to strange undefined behavior
+ * notably if `value` is unsigned, resulting in a large positive `-value`.
*/
/* catch up */
- if (offset) {
+ if (STORED_IS_OFFSET(offcode)) {
if (dictMode == ZSTD_noDict) {
- while ( ((start > anchor) & (start - (offset-ZSTD_REP_MOVE) > prefixLowest))
- && (start[-1] == (start-(offset-ZSTD_REP_MOVE))[-1]) ) /* only search for offset within prefix */
+ while ( ((start > anchor) & (start - STORED_OFFSET(offcode) > prefixLowest))
+ && (start[-1] == (start-STORED_OFFSET(offcode))[-1]) ) /* only search for offset within prefix */
{ start--; matchLength++; }
}
if (isDxS) {
- U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
+ U32 const matchIndex = (U32)((size_t)(start-base) - STORED_OFFSET(offcode));
const BYTE* match = (matchIndex < prefixLowestIndex) ? dictBase + matchIndex - dictIndexDelta : base + matchIndex;
const BYTE* const mStart = (matchIndex < prefixLowestIndex) ? dictLowest : prefixLowest;
while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
}
- offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
+ offset_2 = offset_1; offset_1 = (U32)STORED_OFFSET(offcode);
}
/* store sequence */
_storeSequence:
- { size_t const litLength = start - anchor;
- ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offset, matchLength-MINMATCH);
+ { size_t const litLength = (size_t)(start - anchor);
+ ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offcode, matchLength);
anchor = ip = start + matchLength;
}
@@ -1760,8 +1688,8 @@ _storeSequence:
&& (MEM_read32(repMatch) == MEM_read32(ip)) ) {
const BYTE* const repEnd2 = repIndex < prefixLowestIndex ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd2, prefixLowest) + 4;
- offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset_2 <=> offset_1 */
- ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
+ offcode = offset_2; offset_2 = offset_1; offset_1 = (U32)offcode; /* swap offset_2 <=> offset_1 */
+ ZSTD_storeSeq(seqStore, 0, anchor, iend, STORE_REPCODE_1, matchLength);
ip += matchLength;
anchor = ip;
continue;
@@ -1775,8 +1703,8 @@ _storeSequence:
&& (MEM_read32(ip) == MEM_read32(ip - offset_2)) ) {
/* store sequence */
matchLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
- offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap repcodes */
- ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
+ offcode = offset_2; offset_2 = offset_1; offset_1 = (U32)offcode; /* swap repcodes */
+ ZSTD_storeSeq(seqStore, 0, anchor, iend, STORE_REPCODE_1, matchLength);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
@@ -1955,15 +1883,7 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
const U32 windowLog = ms->cParams.windowLog;
const U32 rowLog = ms->cParams.searchLog < 5 ? 4 : 5;
- typedef size_t (*searchMax_f)(
- ZSTD_matchState_t* ms,
- const BYTE* ip, const BYTE* iLimit, size_t* offsetPtr);
- const searchMax_f searchFuncs[3] = {
- ZSTD_HcFindBestMatch_extDict_selectMLS,
- ZSTD_BtFindBestMatch_extDict_selectMLS,
- ZSTD_RowFindBestMatch_extDict_selectRowLog
- };
- searchMax_f searchMax = searchFuncs[(int)searchMethod];
+ searchMax_f const searchMax = ZSTD_selectLazyVTable(ms, searchMethod, ZSTD_extDict)->searchMax;
U32 offset_1 = rep[0], offset_2 = rep[1];
DEBUGLOG(5, "ZSTD_compressBlock_lazy_extDict_generic (searchFunc=%u)", (U32)searchMethod);
@@ -1985,7 +1905,7 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
#endif
while (ip < ilimit) {
size_t matchLength=0;
- size_t offset=0;
+ size_t offcode=STORE_REPCODE_1;
const BYTE* start=ip+1;
U32 curr = (U32)(ip-base);
@@ -1995,7 +1915,7 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow */
- & (offset_1 < curr+1 - windowLow) ) /* note: we are searching at curr+1 */
+ & (offset_1 <= curr+1 - windowLow) ) /* note: we are searching at curr+1 */
if (MEM_read32(ip+1) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
@@ -2007,10 +1927,10 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
{ size_t offsetFound = 999999999;
size_t const ml2 = searchMax(ms, ip, iend, &offsetFound);
if (ml2 > matchLength)
- matchLength = ml2, start = ip, offset=offsetFound;
+ matchLength = ml2, start = ip, offcode=offsetFound;
}
- if (matchLength < 4) {
+ if (matchLength < 4) {
ip += ((ip-anchor) >> kSearchStrength) + 1; /* jump faster over incompressible sections */
continue;
}
@@ -2021,30 +1941,30 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
ip ++;
curr++;
/* check repCode */
- if (offset) {
+ if (offcode) {
const U32 windowLow = ZSTD_getLowestMatchIndex(ms, curr, windowLog);
const U32 repIndex = (U32)(curr - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow : do not test positions overlapping 2 memory segments */
- & (offset_1 < curr - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */
+ & (offset_1 <= curr - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
int const gain2 = (int)(repLength * 3);
- int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)offset+1) + 1);
+ int const gain1 = (int)(matchLength*3 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 1);
if ((repLength >= 4) && (gain2 > gain1))
- matchLength = repLength, offset = 0, start = ip;
+ matchLength = repLength, offcode = STORE_REPCODE_1, start = ip;
} }
/* search match, depth 1 */
{ size_t offset2=999999999;
size_t const ml2 = searchMax(ms, ip, iend, &offset2);
- int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 4);
+ int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offset2))); /* raw approx */
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 4);
if ((ml2 >= 4) && (gain2 > gain1)) {
- matchLength = ml2, offset = offset2, start = ip;
+ matchLength = ml2, offcode = offset2, start = ip;
continue; /* search a better one */
} }
@@ -2053,48 +1973,48 @@ size_t ZSTD_compressBlock_lazy_extDict_generic(
ip ++;
curr++;
/* check repCode */
- if (offset) {
+ if (offcode) {
const U32 windowLow = ZSTD_getLowestMatchIndex(ms, curr, windowLog);
const U32 repIndex = (U32)(curr - offset_1);
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow : do not test positions overlapping 2 memory segments */
- & (offset_1 < curr - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */
+ & (offset_1 <= curr - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
size_t const repLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
int const gain2 = (int)(repLength * 4);
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 1);
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 1);
if ((repLength >= 4) && (gain2 > gain1))
- matchLength = repLength, offset = 0, start = ip;
+ matchLength = repLength, offcode = STORE_REPCODE_1, start = ip;
} }
/* search match, depth 2 */
{ size_t offset2=999999999;
size_t const ml2 = searchMax(ms, ip, iend, &offset2);
- int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)offset2+1)); /* raw approx */
- int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)offset+1) + 7);
+ int const gain2 = (int)(ml2*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offset2))); /* raw approx */
+ int const gain1 = (int)(matchLength*4 - ZSTD_highbit32((U32)STORED_TO_OFFBASE(offcode)) + 7);
if ((ml2 >= 4) && (gain2 > gain1)) {
- matchLength = ml2, offset = offset2, start = ip;
+ matchLength = ml2, offcode = offset2, start = ip;
continue;
} } }
break; /* nothing found : store previous solution */
}
/* catch up */
- if (offset) {
- U32 const matchIndex = (U32)((start-base) - (offset - ZSTD_REP_MOVE));
+ if (STORED_IS_OFFSET(offcode)) {
+ U32 const matchIndex = (U32)((size_t)(start-base) - STORED_OFFSET(offcode));
const BYTE* match = (matchIndex < dictLimit) ? dictBase + matchIndex : base + matchIndex;
const BYTE* const mStart = (matchIndex < dictLimit) ? dictStart : prefixStart;
while ((start>anchor) && (match>mStart) && (start[-1] == match[-1])) { start--; match--; matchLength++; } /* catch up */
- offset_2 = offset_1; offset_1 = (U32)(offset - ZSTD_REP_MOVE);
+ offset_2 = offset_1; offset_1 = (U32)STORED_OFFSET(offcode);
}
/* store sequence */
_storeSequence:
- { size_t const litLength = start - anchor;
- ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offset, matchLength-MINMATCH);
+ { size_t const litLength = (size_t)(start - anchor);
+ ZSTD_storeSeq(seqStore, litLength, anchor, iend, (U32)offcode, matchLength);
anchor = ip = start + matchLength;
}
@@ -2106,13 +2026,13 @@ _storeSequence:
const BYTE* const repBase = repIndex < dictLimit ? dictBase : base;
const BYTE* const repMatch = repBase + repIndex;
if ( ((U32)((dictLimit-1) - repIndex) >= 3) /* intentional overflow : do not test positions overlapping 2 memory segments */
- & (offset_2 < repCurrent - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */
+ & (offset_2 <= repCurrent - windowLow) ) /* equivalent to `curr > repIndex >= windowLow` */
if (MEM_read32(ip) == MEM_read32(repMatch)) {
/* repcode detected we should take it */
const BYTE* const repEnd = repIndex < dictLimit ? dictEnd : iend;
matchLength = ZSTD_count_2segments(ip+4, repMatch+4, iend, repEnd, prefixStart) + 4;
- offset = offset_2; offset_2 = offset_1; offset_1 = (U32)offset; /* swap offset history */
- ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, matchLength-MINMATCH);
+ offcode = offset_2; offset_2 = offset_1; offset_1 = (U32)offcode; /* swap offset history */
+ ZSTD_storeSeq(seqStore, 0, anchor, iend, STORE_REPCODE_1, matchLength);
ip += matchLength;
anchor = ip;
continue; /* faster when present ... (?) */
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-26 07:47:12 +0000