// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause/* * Copyright (c) Meta Platforms, Inc. and affiliates. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. */ #include "zstd_compress_internal.h"#include "zstd_double_fast.h" #ifndef ZSTD_EXCLUDE_DFAST_BLOCK_COMPRESSOR staticZSTD_ALLOW_POINTER_OVERFLOW_ATTRvoid ZSTD_fillDoubleHashTableForCDict(ZSTD_MatchState_t* ms, void const* end, ZSTD_dictTableLoadMethod_e dtlm){ const ZSTD_compressionParameters* const cParams = &ms->cParams; U32* const hashLarge = ms->hashTable; U32 const hBitsL = cParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS; U32 const mls = cParams->minMatch; U32* const hashSmall = ms->chainTable; U32 const hBitsS = cParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS; const BYTE* const base = ms->window.base; const BYTE* ip = base + ms->nextToUpdate; const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE; const U32 fastHashFillStep = 3; /* Always insert every fastHashFillStep position into the hash tables. * Insert the other positions into the large hash table if their entry * is empty. */ for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) { U32 const curr = (U32)(ip - base); U32 i; for (i = 0; i < fastHashFillStep; ++i) { size_t const smHashAndTag = ZSTD_hashPtr(ip + i, hBitsS, mls); size_t const lgHashAndTag = ZSTD_hashPtr(ip + i, hBitsL, 8); if (i == 0) { ZSTD_writeTaggedIndex(hashSmall, smHashAndTag, curr + i); } if (i == 0 || hashLarge[lgHashAndTag >> ZSTD_SHORT_CACHE_TAG_BITS] == 0) { ZSTD_writeTaggedIndex(hashLarge, lgHashAndTag, curr + i); } /* Only load extra positions for ZSTD_dtlm_full */ if (dtlm == ZSTD_dtlm_fast) break; } }} staticZSTD_ALLOW_POINTER_OVERFLOW_ATTRvoid ZSTD_fillDoubleHashTableForCCtx(ZSTD_MatchState_t* ms, void const* end, ZSTD_dictTableLoadMethod_e dtlm){ const ZSTD_compressionParameters* const cParams = &ms->cParams; U32* const hashLarge = ms->hashTable; U32 const hBitsL = cParams->hashLog; U32 const mls = cParams->minMatch; U32* const hashSmall = ms->chainTable; U32 const hBitsS = cParams->chainLog; const BYTE* const base = ms->window.base; const BYTE* ip = base + ms->nextToUpdate; const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE; const U32 fastHashFillStep = 3; /* Always insert every fastHashFillStep position into the hash tables. * Insert the other positions into the large hash table if their entry * is empty. */ for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) { U32 const curr = (U32)(ip - base); U32 i; for (i = 0; i < fastHashFillStep; ++i) { size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls); size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8); if (i == 0) hashSmall[smHash] = curr + i; if (i == 0 || hashLarge[lgHash] == 0) hashLarge[lgHash] = curr + i; /* Only load extra positions for ZSTD_dtlm_full */ if (dtlm == ZSTD_dtlm_fast) break; } }} void ZSTD_fillDoubleHashTable(ZSTD_MatchState_t* ms, const void* const end, ZSTD_dictTableLoadMethod_e dtlm, ZSTD_tableFillPurpose_e tfp){ if (tfp == ZSTD_tfp_forCDict) { ZSTD_fillDoubleHashTableForCDict(ms, end, dtlm); } else { ZSTD_fillDoubleHashTableForCCtx(ms, end, dtlm); }} FORCE_INLINE_TEMPLATEZSTD_ALLOW_POINTER_OVERFLOW_ATTRsize_t ZSTD_compressBlock_doubleFast_noDict_generic( ZSTD_MatchState_t* ms, SeqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], void const* src, size_t srcSize, U32 const mls /* template */){ ZSTD_compressionParameters const* cParams = &ms->cParams; U32* const hashLong = ms->hashTable; const U32 hBitsL = cParams->hashLog; U32* const hashSmall = ms->chainTable; const U32 hBitsS = cParams->chainLog; const BYTE* const base = ms->window.base; const BYTE* const istart = (const BYTE*)src; const BYTE* anchor = istart; const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); /* presumes that, if there is a dictionary, it must be using Attach mode */ const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog); const BYTE* const prefixLowest = base + prefixLowestIndex; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - HASH_READ_SIZE; U32 offset_1=rep[0], offset_2=rep[1]; U32 offsetSaved1 = 0, offsetSaved2 = 0; size_t mLength; U32 offset; U32 curr; /* how many positions to search before increasing step size */ const size_t kStepIncr = 1 << kSearchStrength; /* the position at which to increment the step size if no match is found */ const BYTE* nextStep; size_t step; /* the current step size */ size_t hl0; /* the long hash at ip */ size_t hl1; /* the long hash at ip1 */ U32 idxl0; /* the long match index for ip */ U32 idxl1; /* the long match index for ip1 */ const BYTE* matchl0; /* the long match for ip */ const BYTE* matchs0; /* the short match for ip */ const BYTE* matchl1; /* the long match for ip1 */ const BYTE* matchs0_safe; /* matchs0 or safe address */ const BYTE* ip = istart; /* the current position */ const BYTE* ip1; /* the next position */ /* Array of ~random data, should have low probability of matching data * we load from here instead of from tables, if matchl0/matchl1 are * invalid indices. Used to avoid unpredictable branches. */ const BYTE dummy[] = {0x12,0x34,0x56,0x78,0x9a,0xbc,0xde,0xf0,0xe2,0xb4}; DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_noDict_generic"); /* init */ ip += ((ip - prefixLowest) == 0); { U32 const current = (U32)(ip - base); U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, current, cParams->windowLog); U32 const maxRep = current - windowLow; if (offset_2 > maxRep) offsetSaved2 = offset_2, offset_2 = 0; if (offset_1 > maxRep) offsetSaved1 = offset_1, offset_1 = 0; } /* Outer Loop: one iteration per match found and stored */ while (1) { step = 1; nextStep = ip + kStepIncr; ip1 = ip + step; if (ip1 > ilimit) { goto _cleanup; } hl0 = ZSTD_hashPtr(ip, hBitsL, 8); idxl0 = hashLong[hl0]; matchl0 = base + idxl0; /* Inner Loop: one iteration per search / position */ do { const size_t hs0 = ZSTD_hashPtr(ip, hBitsS, mls); const U32 idxs0 = hashSmall[hs0]; curr = (U32)(ip-base); matchs0 = base + idxs0; hashLong[hl0] = hashSmall[hs0] = curr; /* update hash tables */ /* check noDict repcode */ if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) { mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4; ip++; ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength); goto _match_stored; } hl1 = ZSTD_hashPtr(ip1, hBitsL, 8); /* idxl0 > prefixLowestIndex is a (somewhat) unpredictable branch. * However expression below complies into conditional move. Since * match is unlikely and we only *branch* on idxl0 > prefixLowestIndex * if there is a match, all branches become predictable. */ { const BYTE* const matchl0_safe = ZSTD_selectAddr(idxl0, prefixLowestIndex, matchl0, &dummy[0]); /* check prefix long match */ if (MEM_read64(matchl0_safe) == MEM_read64(ip) && matchl0_safe == matchl0) { mLength = ZSTD_count(ip+8, matchl0+8, iend) + 8; offset = (U32)(ip-matchl0); while (((ip>anchor) & (matchl0>prefixLowest)) && (ip[-1] == matchl0[-1])) { ip--; matchl0--; mLength++; } /* catch up */ goto _match_found; } } idxl1 = hashLong[hl1]; matchl1 = base + idxl1; /* Same optimization as matchl0 above */ matchs0_safe = ZSTD_selectAddr(idxs0, prefixLowestIndex, matchs0, &dummy[0]); /* check prefix short match */ if(MEM_read32(matchs0_safe) == MEM_read32(ip) && matchs0_safe == matchs0) { goto _search_next_long; } if (ip1 >= nextStep) { PREFETCH_L1(ip1 + 64); PREFETCH_L1(ip1 + 128); step++; nextStep += kStepIncr; } ip = ip1; ip1 += step; hl0 = hl1; idxl0 = idxl1; matchl0 = matchl1; #if defined(__aarch64__) PREFETCH_L1(ip+256); #endif } while (ip1 <= ilimit); _cleanup: /* If offset_1 started invalid (offsetSaved1 != 0) and became valid (offset_1 != 0), * rotate saved offsets. See comment in ZSTD_compressBlock_fast_noDict for more context. */ offsetSaved2 = ((offsetSaved1 != 0) && (offset_1 != 0)) ? offsetSaved1 : offsetSaved2; /* save reps for next block */ rep[0] = offset_1 ? offset_1 : offsetSaved1; rep[1] = offset_2 ? offset_2 : offsetSaved2; /* Return the last literals size */ return (size_t)(iend - anchor); _search_next_long: /* short match found: let's check for a longer one */ mLength = ZSTD_count(ip+4, matchs0+4, iend) + 4; offset = (U32)(ip - matchs0); /* check long match at +1 position */ if ((idxl1 > prefixLowestIndex) && (MEM_read64(matchl1) == MEM_read64(ip1))) { size_t const l1len = ZSTD_count(ip1+8, matchl1+8, iend) + 8; if (l1len > mLength) { /* use the long match instead */ ip = ip1; mLength = l1len; offset = (U32)(ip-matchl1); matchs0 = matchl1; } } while (((ip>anchor) & (matchs0>prefixLowest)) && (ip[-1] == matchs0[-1])) { ip--; matchs0--; mLength++; } /* complete backward */ /* fall-through */ _match_found: /* requires ip, offset, mLength */ offset_2 = offset_1; offset_1 = offset; if (step < 4) { /* It is unsafe to write this value back to the hashtable when ip1 is * greater than or equal to the new ip we will have after we're done * processing this match. Rather than perform that test directly * (ip1 >= ip + mLength), which costs speed in practice, we do a simpler * more predictable test. The minmatch even if we take a short match is * 4 bytes, so as long as step, the distance between ip and ip1 * (initially) is less than 4, we know ip1 < new ip. */ hashLong[hl1] = (U32)(ip1 - base); } ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength); _match_stored: /* match found */ ip += mLength; anchor = ip; if (ip <= ilimit) { /* Complementary insertion */ /* done after iLimit test, as candidates could be > iend-8 */ { U32 const indexToInsert = curr+2; hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert; hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base); hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert; hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base); } /* check immediate repcode */ while ( (ip <= ilimit) && ( (offset_2>0) & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) { /* store sequence */ size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4; U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; /* swap offset_2 <=> offset_1 */ hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base); hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base); ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, rLength); ip += rLength; anchor = ip; continue; /* faster when present ... (?) */ } } }} FORCE_INLINE_TEMPLATEZSTD_ALLOW_POINTER_OVERFLOW_ATTRsize_t ZSTD_compressBlock_doubleFast_dictMatchState_generic( ZSTD_MatchState_t* ms, SeqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], void const* src, size_t srcSize, U32 const mls /* template */){ ZSTD_compressionParameters const* cParams = &ms->cParams; U32* const hashLong = ms->hashTable; const U32 hBitsL = cParams->hashLog; U32* const hashSmall = ms->chainTable; const U32 hBitsS = cParams->chainLog; const BYTE* const base = ms->window.base; const BYTE* const istart = (const BYTE*)src; const BYTE* ip = istart; const BYTE* anchor = istart; const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); /* presumes that, if there is a dictionary, it must be using Attach mode */ const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog); const BYTE* const prefixLowest = base + prefixLowestIndex; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - HASH_READ_SIZE; U32 offset_1=rep[0], offset_2=rep[1]; const ZSTD_MatchState_t* const dms = ms->dictMatchState; const ZSTD_compressionParameters* const dictCParams = &dms->cParams; const U32* const dictHashLong = dms->hashTable; const U32* const dictHashSmall = dms->chainTable; const U32 dictStartIndex = dms->window.dictLimit; const BYTE* const dictBase = dms->window.base; const BYTE* const dictStart = dictBase + dictStartIndex; const BYTE* const dictEnd = dms->window.nextSrc; const U32 dictIndexDelta = prefixLowestIndex - (U32)(dictEnd - dictBase); const U32 dictHBitsL = dictCParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS; const U32 dictHBitsS = dictCParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS; const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictStart)); DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_dictMatchState_generic"); /* if a dictionary is attached, it must be within window range */ assert(ms->window.dictLimit + (1U << cParams->windowLog) >= endIndex); if (ms->prefetchCDictTables) { size_t const hashTableBytes = (((size_t)1) << dictCParams->hashLog) * sizeof(U32); size_t const chainTableBytes = (((size_t)1) << dictCParams->chainLog) * sizeof(U32); PREFETCH_AREA(dictHashLong, hashTableBytes); PREFETCH_AREA(dictHashSmall, chainTableBytes); } /* init */ ip += (dictAndPrefixLength == 0); /* dictMatchState repCode checks don't currently handle repCode == 0 * disabling. */ assert(offset_1 <= dictAndPrefixLength); assert(offset_2 <= dictAndPrefixLength); /* Main Search Loop */ while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */ size_t mLength; U32 offset; size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8); size_t const h = ZSTD_hashPtr(ip, hBitsS, mls); size_t const dictHashAndTagL = ZSTD_hashPtr(ip, dictHBitsL, 8); size_t const dictHashAndTagS = ZSTD_hashPtr(ip, dictHBitsS, mls); U32 const dictMatchIndexAndTagL = dictHashLong[dictHashAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS]; U32 const dictMatchIndexAndTagS = dictHashSmall[dictHashAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS]; int const dictTagsMatchL = ZSTD_comparePackedTags(dictMatchIndexAndTagL, dictHashAndTagL); int const dictTagsMatchS = ZSTD_comparePackedTags(dictMatchIndexAndTagS, dictHashAndTagS); U32 const curr = (U32)(ip-base); U32 const matchIndexL = hashLong[h2]; U32 matchIndexS = hashSmall[h]; const BYTE* matchLong = base + matchIndexL; const BYTE* match = base + matchIndexS; const U32 repIndex = curr + 1 - offset_1; const BYTE* repMatch = (repIndex < prefixLowestIndex) ? dictBase + (repIndex - dictIndexDelta) : base + repIndex; hashLong[h2] = hashSmall[h] = curr; /* update hash tables */ /* check repcode */ if ((ZSTD_index_overlap_check(prefixLowestIndex, repIndex)) && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend; mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4; ip++; ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength); goto _match_stored; } if ((matchIndexL >= prefixLowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) { /* check prefix long match */ mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8; offset = (U32)(ip-matchLong); while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */ goto _match_found; } else if (dictTagsMatchL) { /* check dictMatchState long match */ U32 const dictMatchIndexL = dictMatchIndexAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS; const BYTE* dictMatchL = dictBase + dictMatchIndexL; assert(dictMatchL < dictEnd); if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) { mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8; offset = (U32)(curr - dictMatchIndexL - dictIndexDelta); while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */ goto _match_found; } } if (matchIndexS > prefixLowestIndex) { /* short match candidate */ if (MEM_read32(match) == MEM_read32(ip)) { goto _search_next_long; } } else if (dictTagsMatchS) { /* check dictMatchState short match */ U32 const dictMatchIndexS = dictMatchIndexAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS; match = dictBase + dictMatchIndexS; matchIndexS = dictMatchIndexS + dictIndexDelta; if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) { goto _search_next_long; } } ip += ((ip-anchor) >> kSearchStrength) + 1;#if defined(__aarch64__) PREFETCH_L1(ip+256);#endif continue; _search_next_long: { size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8); size_t const dictHashAndTagL3 = ZSTD_hashPtr(ip+1, dictHBitsL, 8); U32 const matchIndexL3 = hashLong[hl3]; U32 const dictMatchIndexAndTagL3 = dictHashLong[dictHashAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS]; int const dictTagsMatchL3 = ZSTD_comparePackedTags(dictMatchIndexAndTagL3, dictHashAndTagL3); const BYTE* matchL3 = base + matchIndexL3; hashLong[hl3] = curr + 1; /* check prefix long +1 match */ if ((matchIndexL3 >= prefixLowestIndex) && (MEM_read64(matchL3) == MEM_read64(ip+1))) { mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8; ip++; offset = (U32)(ip-matchL3); while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */ goto _match_found; } else if (dictTagsMatchL3) { /* check dict long +1 match */ U32 const dictMatchIndexL3 = dictMatchIndexAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS; const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3; assert(dictMatchL3 < dictEnd); if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) { mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8; ip++; offset = (U32)(curr + 1 - dictMatchIndexL3 - dictIndexDelta); while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */ goto _match_found; } } } /* if no long +1 match, explore the short match we found */ if (matchIndexS < prefixLowestIndex) { mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4; offset = (U32)(curr - matchIndexS); while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ } else { mLength = ZSTD_count(ip+4, match+4, iend) + 4; offset = (U32)(ip - match); while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ } _match_found: offset_2 = offset_1; offset_1 = offset; Lines 1–500 of 779. 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// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause /* * Copyright (c) Meta Platforms, Inc. and affiliates. * All rights reserved. * * This source code is licensed under both the BSD-style license (found in the * LICENSE file in the root directory of this source tree) and the GPLv2 (found * in the COPYING file in the root directory of this source tree). * You may select, at your option, one of the above-listed licenses. */ #include "zstd_compress_internal.h" #include "zstd_double_fast.h" #ifndef ZSTD_EXCLUDE_DFAST_BLOCK_COMPRESSOR static ZSTD_ALLOW_POINTER_OVERFLOW_ATTR void ZSTD_fillDoubleHashTableForCDict(ZSTD_MatchState_t* ms, void const* end, ZSTD_dictTableLoadMethod_e dtlm) { const ZSTD_compressionParameters* const cParams = &ms->cParams; U32* const hashLarge = ms->hashTable; U32 const hBitsL = cParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS; U32 const mls = cParams->minMatch; U32* const hashSmall = ms->chainTable; U32 const hBitsS = cParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS; const BYTE* const base = ms->window.base; const BYTE* ip = base + ms->nextToUpdate; const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE; const U32 fastHashFillStep = 3; /* Always insert every fastHashFillStep position into the hash tables. * Insert the other positions into the large hash table if their entry * is empty. */ for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) { U32 const curr = (U32)(ip - base); U32 i; for (i = 0; i < fastHashFillStep; ++i) { size_t const smHashAndTag = ZSTD_hashPtr(ip + i, hBitsS, mls); size_t const lgHashAndTag = ZSTD_hashPtr(ip + i, hBitsL, 8); if (i == 0) { ZSTD_writeTaggedIndex(hashSmall, smHashAndTag, curr + i); } if (i == 0 || hashLarge[lgHashAndTag >> ZSTD_SHORT_CACHE_TAG_BITS] == 0) { ZSTD_writeTaggedIndex(hashLarge, lgHashAndTag, curr + i); } /* Only load extra positions for ZSTD_dtlm_full */ if (dtlm == ZSTD_dtlm_fast) break; } } } static ZSTD_ALLOW_POINTER_OVERFLOW_ATTR void ZSTD_fillDoubleHashTableForCCtx(ZSTD_MatchState_t* ms, void const* end, ZSTD_dictTableLoadMethod_e dtlm) { const ZSTD_compressionParameters* const cParams = &ms->cParams; U32* const hashLarge = ms->hashTable; U32 const hBitsL = cParams->hashLog; U32 const mls = cParams->minMatch; U32* const hashSmall = ms->chainTable; U32 const hBitsS = cParams->chainLog; const BYTE* const base = ms->window.base; const BYTE* ip = base + ms->nextToUpdate; const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE; const U32 fastHashFillStep = 3; /* Always insert every fastHashFillStep position into the hash tables. * Insert the other positions into the large hash table if their entry * is empty. */ for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) { U32 const curr = (U32)(ip - base); U32 i; for (i = 0; i < fastHashFillStep; ++i) { size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls); size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8); if (i == 0) hashSmall[smHash] = curr + i; if (i == 0 || hashLarge[lgHash] == 0) hashLarge[lgHash] = curr + i; /* Only load extra positions for ZSTD_dtlm_full */ if (dtlm == ZSTD_dtlm_fast) break; } } } void ZSTD_fillDoubleHashTable(ZSTD_MatchState_t* ms, const void* const end, ZSTD_dictTableLoadMethod_e dtlm, ZSTD_tableFillPurpose_e tfp) { if (tfp == ZSTD_tfp_forCDict) { ZSTD_fillDoubleHashTableForCDict(ms, end, dtlm); } else { ZSTD_fillDoubleHashTableForCCtx(ms, end, dtlm); } } FORCE_INLINE_TEMPLATE ZSTD_ALLOW_POINTER_OVERFLOW_ATTR size_t ZSTD_compressBlock_doubleFast_noDict_generic( ZSTD_MatchState_t* ms, SeqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], void const* src, size_t srcSize, U32 const mls /* template */) { ZSTD_compressionParameters const* cParams = &ms->cParams; U32* const hashLong = ms->hashTable; const U32 hBitsL = cParams->hashLog; U32* const hashSmall = ms->chainTable; const U32 hBitsS = cParams->chainLog; const BYTE* const base = ms->window.base; const BYTE* const istart = (const BYTE*)src; const BYTE* anchor = istart; const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); /* presumes that, if there is a dictionary, it must be using Attach mode */ const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog); const BYTE* const prefixLowest = base + prefixLowestIndex; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - HASH_READ_SIZE; U32 offset_1=rep[0], offset_2=rep[1]; U32 offsetSaved1 = 0, offsetSaved2 = 0; size_t mLength; U32 offset; U32 curr; /* how many positions to search before increasing step size */ const size_t kStepIncr = 1 << kSearchStrength; /* the position at which to increment the step size if no match is found */ const BYTE* nextStep; size_t step; /* the current step size */ size_t hl0; /* the long hash at ip */ size_t hl1; /* the long hash at ip1 */ U32 idxl0; /* the long match index for ip */ U32 idxl1; /* the long match index for ip1 */ const BYTE* matchl0; /* the long match for ip */ const BYTE* matchs0; /* the short match for ip */ const BYTE* matchl1; /* the long match for ip1 */ const BYTE* matchs0_safe; /* matchs0 or safe address */ const BYTE* ip = istart; /* the current position */ const BYTE* ip1; /* the next position */ /* Array of ~random data, should have low probability of matching data * we load from here instead of from tables, if matchl0/matchl1 are * invalid indices. Used to avoid unpredictable branches. */ const BYTE dummy[] = {0x12,0x34,0x56,0x78,0x9a,0xbc,0xde,0xf0,0xe2,0xb4}; DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_noDict_generic"); /* init */ ip += ((ip - prefixLowest) == 0); { U32 const current = (U32)(ip - base); U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, current, cParams->windowLog); U32 const maxRep = current - windowLow; if (offset_2 > maxRep) offsetSaved2 = offset_2, offset_2 = 0; if (offset_1 > maxRep) offsetSaved1 = offset_1, offset_1 = 0; } /* Outer Loop: one iteration per match found and stored */ while (1) { step = 1; nextStep = ip + kStepIncr; ip1 = ip + step; if (ip1 > ilimit) { goto _cleanup; } hl0 = ZSTD_hashPtr(ip, hBitsL, 8); idxl0 = hashLong[hl0]; matchl0 = base + idxl0; /* Inner Loop: one iteration per search / position */ do { const size_t hs0 = ZSTD_hashPtr(ip, hBitsS, mls); const U32 idxs0 = hashSmall[hs0]; curr = (U32)(ip-base); matchs0 = base + idxs0; hashLong[hl0] = hashSmall[hs0] = curr; /* update hash tables */ /* check noDict repcode */ if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) { mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4; ip++; ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength); goto _match_stored; } hl1 = ZSTD_hashPtr(ip1, hBitsL, 8); /* idxl0 > prefixLowestIndex is a (somewhat) unpredictable branch. * However expression below complies into conditional move. Since * match is unlikely and we only *branch* on idxl0 > prefixLowestIndex * if there is a match, all branches become predictable. */ { const BYTE* const matchl0_safe = ZSTD_selectAddr(idxl0, prefixLowestIndex, matchl0, &dummy[0]); /* check prefix long match */ if (MEM_read64(matchl0_safe) == MEM_read64(ip) && matchl0_safe == matchl0) { mLength = ZSTD_count(ip+8, matchl0+8, iend) + 8; offset = (U32)(ip-matchl0); while (((ip>anchor) & (matchl0>prefixLowest)) && (ip[-1] == matchl0[-1])) { ip--; matchl0--; mLength++; } /* catch up */ goto _match_found; } } idxl1 = hashLong[hl1]; matchl1 = base + idxl1; /* Same optimization as matchl0 above */ matchs0_safe = ZSTD_selectAddr(idxs0, prefixLowestIndex, matchs0, &dummy[0]); /* check prefix short match */ if(MEM_read32(matchs0_safe) == MEM_read32(ip) && matchs0_safe == matchs0) { goto _search_next_long; } if (ip1 >= nextStep) { PREFETCH_L1(ip1 + 64); PREFETCH_L1(ip1 + 128); step++; nextStep += kStepIncr; } ip = ip1; ip1 += step; hl0 = hl1; idxl0 = idxl1; matchl0 = matchl1; #if defined(__aarch64__) PREFETCH_L1(ip+256); #endif } while (ip1 <= ilimit); _cleanup: /* If offset_1 started invalid (offsetSaved1 != 0) and became valid (offset_1 != 0), * rotate saved offsets. See comment in ZSTD_compressBlock_fast_noDict for more context. */ offsetSaved2 = ((offsetSaved1 != 0) && (offset_1 != 0)) ? offsetSaved1 : offsetSaved2; /* save reps for next block */ rep[0] = offset_1 ? offset_1 : offsetSaved1; rep[1] = offset_2 ? offset_2 : offsetSaved2; /* Return the last literals size */ return (size_t)(iend - anchor); _search_next_long: /* short match found: let's check for a longer one */ mLength = ZSTD_count(ip+4, matchs0+4, iend) + 4; offset = (U32)(ip - matchs0); /* check long match at +1 position */ if ((idxl1 > prefixLowestIndex) && (MEM_read64(matchl1) == MEM_read64(ip1))) { size_t const l1len = ZSTD_count(ip1+8, matchl1+8, iend) + 8; if (l1len > mLength) { /* use the long match instead */ ip = ip1; mLength = l1len; offset = (U32)(ip-matchl1); matchs0 = matchl1; } } while (((ip>anchor) & (matchs0>prefixLowest)) && (ip[-1] == matchs0[-1])) { ip--; matchs0--; mLength++; } /* complete backward */ /* fall-through */ _match_found: /* requires ip, offset, mLength */ offset_2 = offset_1; offset_1 = offset; if (step < 4) { /* It is unsafe to write this value back to the hashtable when ip1 is * greater than or equal to the new ip we will have after we're done * processing this match. Rather than perform that test directly * (ip1 >= ip + mLength), which costs speed in practice, we do a simpler * more predictable test. The minmatch even if we take a short match is * 4 bytes, so as long as step, the distance between ip and ip1 * (initially) is less than 4, we know ip1 < new ip. */ hashLong[hl1] = (U32)(ip1 - base); } ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength); _match_stored: /* match found */ ip += mLength; anchor = ip; if (ip <= ilimit) { /* Complementary insertion */ /* done after iLimit test, as candidates could be > iend-8 */ { U32 const indexToInsert = curr+2; hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert; hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base); hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert; hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base); } /* check immediate repcode */ while ( (ip <= ilimit) && ( (offset_2>0) & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) { /* store sequence */ size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4; U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; /* swap offset_2 <=> offset_1 */ hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base); hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base); ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, rLength); ip += rLength; anchor = ip; continue; /* faster when present ... (?) */ } } } } FORCE_INLINE_TEMPLATE ZSTD_ALLOW_POINTER_OVERFLOW_ATTR size_t ZSTD_compressBlock_doubleFast_dictMatchState_generic( ZSTD_MatchState_t* ms, SeqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], void const* src, size_t srcSize, U32 const mls /* template */) { ZSTD_compressionParameters const* cParams = &ms->cParams; U32* const hashLong = ms->hashTable; const U32 hBitsL = cParams->hashLog; U32* const hashSmall = ms->chainTable; const U32 hBitsS = cParams->chainLog; const BYTE* const base = ms->window.base; const BYTE* const istart = (const BYTE*)src; const BYTE* ip = istart; const BYTE* anchor = istart; const U32 endIndex = (U32)((size_t)(istart - base) + srcSize); /* presumes that, if there is a dictionary, it must be using Attach mode */ const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog); const BYTE* const prefixLowest = base + prefixLowestIndex; const BYTE* const iend = istart + srcSize; const BYTE* const ilimit = iend - HASH_READ_SIZE; U32 offset_1=rep[0], offset_2=rep[1]; const ZSTD_MatchState_t* const dms = ms->dictMatchState; const ZSTD_compressionParameters* const dictCParams = &dms->cParams; const U32* const dictHashLong = dms->hashTable; const U32* const dictHashSmall = dms->chainTable; const U32 dictStartIndex = dms->window.dictLimit; const BYTE* const dictBase = dms->window.base; const BYTE* const dictStart = dictBase + dictStartIndex; const BYTE* const dictEnd = dms->window.nextSrc; const U32 dictIndexDelta = prefixLowestIndex - (U32)(dictEnd - dictBase); const U32 dictHBitsL = dictCParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS; const U32 dictHBitsS = dictCParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS; const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictStart)); DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_dictMatchState_generic"); /* if a dictionary is attached, it must be within window range */ assert(ms->window.dictLimit + (1U << cParams->windowLog) >= endIndex); if (ms->prefetchCDictTables) { size_t const hashTableBytes = (((size_t)1) << dictCParams->hashLog) * sizeof(U32); size_t const chainTableBytes = (((size_t)1) << dictCParams->chainLog) * sizeof(U32); PREFETCH_AREA(dictHashLong, hashTableBytes); PREFETCH_AREA(dictHashSmall, chainTableBytes); } /* init */ ip += (dictAndPrefixLength == 0); /* dictMatchState repCode checks don't currently handle repCode == 0 * disabling. */ assert(offset_1 <= dictAndPrefixLength); assert(offset_2 <= dictAndPrefixLength); /* Main Search Loop */ while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */ size_t mLength; U32 offset; size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8); size_t const h = ZSTD_hashPtr(ip, hBitsS, mls); size_t const dictHashAndTagL = ZSTD_hashPtr(ip, dictHBitsL, 8); size_t const dictHashAndTagS = ZSTD_hashPtr(ip, dictHBitsS, mls); U32 const dictMatchIndexAndTagL = dictHashLong[dictHashAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS]; U32 const dictMatchIndexAndTagS = dictHashSmall[dictHashAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS]; int const dictTagsMatchL = ZSTD_comparePackedTags(dictMatchIndexAndTagL, dictHashAndTagL); int const dictTagsMatchS = ZSTD_comparePackedTags(dictMatchIndexAndTagS, dictHashAndTagS); U32 const curr = (U32)(ip-base); U32 const matchIndexL = hashLong[h2]; U32 matchIndexS = hashSmall[h]; const BYTE* matchLong = base + matchIndexL; const BYTE* match = base + matchIndexS; const U32 repIndex = curr + 1 - offset_1; const BYTE* repMatch = (repIndex < prefixLowestIndex) ? dictBase + (repIndex - dictIndexDelta) : base + repIndex; hashLong[h2] = hashSmall[h] = curr; /* update hash tables */ /* check repcode */ if ((ZSTD_index_overlap_check(prefixLowestIndex, repIndex)) && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) { const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend; mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4; ip++; ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength); goto _match_stored; } if ((matchIndexL >= prefixLowestIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) { /* check prefix long match */ mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8; offset = (U32)(ip-matchLong); while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */ goto _match_found; } else if (dictTagsMatchL) { /* check dictMatchState long match */ U32 const dictMatchIndexL = dictMatchIndexAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS; const BYTE* dictMatchL = dictBase + dictMatchIndexL; assert(dictMatchL < dictEnd); if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) { mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8; offset = (U32)(curr - dictMatchIndexL - dictIndexDelta); while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */ goto _match_found; } } if (matchIndexS > prefixLowestIndex) { /* short match candidate */ if (MEM_read32(match) == MEM_read32(ip)) { goto _search_next_long; } } else if (dictTagsMatchS) { /* check dictMatchState short match */ U32 const dictMatchIndexS = dictMatchIndexAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS; match = dictBase + dictMatchIndexS; matchIndexS = dictMatchIndexS + dictIndexDelta; if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) { goto _search_next_long; } } ip += ((ip-anchor) >> kSearchStrength) + 1; #if defined(__aarch64__) PREFETCH_L1(ip+256); #endif continue; _search_next_long: { size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8); size_t const dictHashAndTagL3 = ZSTD_hashPtr(ip+1, dictHBitsL, 8); U32 const matchIndexL3 = hashLong[hl3]; U32 const dictMatchIndexAndTagL3 = dictHashLong[dictHashAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS]; int const dictTagsMatchL3 = ZSTD_comparePackedTags(dictMatchIndexAndTagL3, dictHashAndTagL3); const BYTE* matchL3 = base + matchIndexL3; hashLong[hl3] = curr + 1; /* check prefix long +1 match */ if ((matchIndexL3 >= prefixLowestIndex) && (MEM_read64(matchL3) == MEM_read64(ip+1))) { mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8; ip++; offset = (U32)(ip-matchL3); while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */ goto _match_found; } else if (dictTagsMatchL3) { /* check dict long +1 match */ U32 const dictMatchIndexL3 = dictMatchIndexAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS; const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3; assert(dictMatchL3 < dictEnd); if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) { mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8; ip++; offset = (U32)(curr + 1 - dictMatchIndexL3 - dictIndexDelta); while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */ goto _match_found; } } } /* if no long +1 match, explore the short match we found */ if (matchIndexS < prefixLowestIndex) { mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4; offset = (U32)(curr - matchIndexS); while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ } else { mLength = ZSTD_count(ip+4, match+4, iend) + 4; offset = (U32)(ip - match); while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */ } _match_found: offset_2 = offset_1; offset_1 = offset;