FreeBSD/Linux Kernel Cross Reference
sys/contrib/openzfs/module/zstd/lib/compress/zstd_double_fast.c

     /*
      * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
      * 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"
    
    
    void ZSTD_fillDoubleHashTable(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 current = (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] = current + i;
                if (i == 0 || hashLarge[lgHash] == 0)
                    hashLarge[lgHash] = current + i;
                /* Only load extra positions for ZSTD_dtlm_full */
                if (dtlm == ZSTD_dtlm_fast)
                    break;
        }   }
    }
    
    
    FORCE_INLINE_TEMPLATE
    size_t ZSTD_compressBlock_doubleFast_generic(
            ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
            void const* src, size_t srcSize,
            U32 const mls /* template */, ZSTD_dictMode_e const dictMode)
    {
        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];
        U32 offsetSaved = 0;
    
        const ZSTD_matchState_t* const dms = ms->dictMatchState;
        const ZSTD_compressionParameters* const dictCParams =
                                         dictMode == ZSTD_dictMatchState ?
                                         &dms->cParams : NULL;
        const U32* const dictHashLong  = dictMode == ZSTD_dictMatchState ?
                                         dms->hashTable : NULL;
        const U32* const dictHashSmall = dictMode == ZSTD_dictMatchState ?
                                         dms->chainTable : NULL;
        const U32 dictStartIndex       = dictMode == ZSTD_dictMatchState ?
                                         dms->window.dictLimit : 0;
        const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
                                         dms->window.base : NULL;
        const BYTE* const dictStart    = dictMode == ZSTD_dictMatchState ?
                                         dictBase + dictStartIndex : NULL;
        const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
                                         dms->window.nextSrc : NULL;
        const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
                                         prefixLowestIndex - (U32)(dictEnd - dictBase) :
                                         0;
        const U32 dictHBitsL           = dictMode == ZSTD_dictMatchState ?
                                         dictCParams->hashLog : hBitsL;
        const U32 dictHBitsS           = dictMode == ZSTD_dictMatchState ?
                                         dictCParams->chainLog : hBitsS;
        const U32 dictAndPrefixLength  = (U32)((ip - prefixLowest) + (dictEnd - dictStart));
    
        DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_generic");
   
       assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
   
       /* if a dictionary is attached, it must be within window range */
       if (dictMode == ZSTD_dictMatchState) {
           assert(ms->window.dictLimit + (1U << cParams->windowLog) >= endIndex);
       }
   
       /* init */
       ip += (dictAndPrefixLength == 0);
       if (dictMode == ZSTD_noDict) {
           U32 const current = (U32)(ip - base);
           U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, current, cParams->windowLog);
           U32 const maxRep = current - windowLow;
           if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
           if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
       }
       if (dictMode == ZSTD_dictMatchState) {
           /* 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 dictHL = ZSTD_hashPtr(ip, dictHBitsL, 8);
           size_t const dictHS = ZSTD_hashPtr(ip, dictHBitsS, mls);
           U32 const current = (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 = current + 1 - offset_1;
           const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
                               && repIndex < prefixLowestIndex) ?
                                  dictBase + (repIndex - dictIndexDelta) :
                                  base + repIndex;
           hashLong[h2] = hashSmall[h] = current;   /* update hash tables */
   
           /* check dictMatchState repcode */
           if (dictMode == ZSTD_dictMatchState
               && ((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
               && (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, 0, mLength-MINMATCH);
               goto _match_stored;
           }
   
           /* check noDict repcode */
           if ( dictMode == ZSTD_noDict
             && ((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, 0, mLength-MINMATCH);
               goto _match_stored;
           }
   
           if (matchIndexL > prefixLowestIndex) {
               /* check prefix long match */
               if (MEM_read64(matchLong) == MEM_read64(ip)) {
                   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 (dictMode == ZSTD_dictMatchState) {
               /* check dictMatchState long match */
               U32 const dictMatchIndexL = dictHashLong[dictHL];
               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)(current - dictMatchIndexL - dictIndexDelta);
                   while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
                   goto _match_found;
           }   }
   
           if (matchIndexS > prefixLowestIndex) {
               /* check prefix short match */
               if (MEM_read32(match) == MEM_read32(ip)) {
                   goto _search_next_long;
               }
           } else if (dictMode == ZSTD_dictMatchState) {
               /* check dictMatchState short match */
               U32 const dictMatchIndexS = dictHashSmall[dictHS];
               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 dictHLNext = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
               U32 const matchIndexL3 = hashLong[hl3];
               const BYTE* matchL3 = base + matchIndexL3;
               hashLong[hl3] = current + 1;
   
               /* check prefix long +1 match */
               if (matchIndexL3 > prefixLowestIndex) {
                   if (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 (dictMode == ZSTD_dictMatchState) {
                   /* check dict long +1 match */
                   U32 const dictMatchIndexL3 = dictHashLong[dictHLNext];
                   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)(current + 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 (dictMode == ZSTD_dictMatchState && matchIndexS < prefixLowestIndex) {
               mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4;
               offset = (U32)(current - 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 */
           }
   
           /* fall-through */
   
   _match_found:
           offset_2 = offset_1;
           offset_1 = offset;
   
           ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
   
   _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 = current+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 */
               if (dictMode == ZSTD_dictMatchState) {
                   while (ip <= ilimit) {
                       U32 const current2 = (U32)(ip-base);
                       U32 const repIndex2 = current2 - offset_2;
                       const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
                           && repIndex2 < prefixLowestIndex ?
                               dictBase + repIndex2 - dictIndexDelta :
                               base + repIndex2;
                       if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
                          && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                           const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
                           size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
                           U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
                           ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
                           hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
                           hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
                           ip += repLength2;
                           anchor = ip;
                           continue;
                       }
                       break;
               }   }
   
               if (dictMode == ZSTD_noDict) {
                   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, 0, rLength-MINMATCH);
                       ip += rLength;
                       anchor = ip;
                       continue;   /* faster when present ... (?) */
           }   }   }
       }   /* while (ip < ilimit) */
   
       /* save reps for next block */
       rep[0] = offset_1 ? offset_1 : offsetSaved;
       rep[1] = offset_2 ? offset_2 : offsetSaved;
   
       /* Return the last literals size */
       return (size_t)(iend - anchor);
   }
   
   
   size_t ZSTD_compressBlock_doubleFast(
           ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
           void const* src, size_t srcSize)
   {
       const U32 mls = ms->cParams.minMatch;
       switch(mls)
       {
       default: /* includes case 3 */
       case 4 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_noDict);
       case 5 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_noDict);
       case 6 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_noDict);
       case 7 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_noDict);
       }
   }
   
   
   size_t ZSTD_compressBlock_doubleFast_dictMatchState(
           ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
           void const* src, size_t srcSize)
   {
       const U32 mls = ms->cParams.minMatch;
       switch(mls)
       {
       default: /* includes case 3 */
       case 4 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_dictMatchState);
       case 5 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_dictMatchState);
       case 6 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_dictMatchState);
       case 7 :
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_dictMatchState);
       }
   }
   
   
   static size_t ZSTD_compressBlock_doubleFast_extDict_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;
       U32  const hBitsL = cParams->hashLog;
       U32* const hashSmall = ms->chainTable;
       U32  const hBitsS = cParams->chainLog;
       const BYTE* const istart = (const BYTE*)src;
       const BYTE* ip = istart;
       const BYTE* anchor = istart;
       const BYTE* const iend = istart + srcSize;
       const BYTE* const ilimit = iend - 8;
       const BYTE* const base = ms->window.base;
       const U32   endIndex = (U32)((size_t)(istart - base) + srcSize);
       const U32   lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
       const U32   dictStartIndex = lowLimit;
       const U32   dictLimit = ms->window.dictLimit;
       const U32   prefixStartIndex = (dictLimit > lowLimit) ? dictLimit : lowLimit;
       const BYTE* const prefixStart = base + prefixStartIndex;
       const BYTE* const dictBase = ms->window.dictBase;
       const BYTE* const dictStart = dictBase + dictStartIndex;
       const BYTE* const dictEnd = dictBase + prefixStartIndex;
       U32 offset_1=rep[0], offset_2=rep[1];
   
       DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
   
       /* if extDict is invalidated due to maxDistance, switch to "regular" variant */
       if (prefixStartIndex == dictStartIndex)
           return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, mls, ZSTD_noDict);
   
       /* Search Loop */
       while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
           const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
           const U32 matchIndex = hashSmall[hSmall];
           const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
           const BYTE* match = matchBase + matchIndex;
   
           const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
           const U32 matchLongIndex = hashLong[hLong];
           const BYTE* const matchLongBase = matchLongIndex < prefixStartIndex ? dictBase : base;
           const BYTE* matchLong = matchLongBase + matchLongIndex;
   
           const U32 current = (U32)(ip-base);
           const U32 repIndex = current + 1 - offset_1;   /* offset_1 expected <= current +1 */
           const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
           const BYTE* const repMatch = repBase + repIndex;
           size_t mLength;
           hashSmall[hSmall] = hashLong[hLong] = current;   /* update hash table */
   
           if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
               & (repIndex > dictStartIndex))
             && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
               const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
               mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
               ip++;
               ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
           } else {
               if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
                   const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
                   const BYTE* const lowMatchPtr = matchLongIndex < prefixStartIndex ? dictStart : prefixStart;
                   U32 offset;
                   mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, prefixStart) + 8;
                   offset = current - matchLongIndex;
                   while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; }   /* catch up */
                   offset_2 = offset_1;
                   offset_1 = offset;
                   ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
   
               } else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
                   size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
                   U32 const matchIndex3 = hashLong[h3];
                   const BYTE* const match3Base = matchIndex3 < prefixStartIndex ? dictBase : base;
                   const BYTE* match3 = match3Base + matchIndex3;
                   U32 offset;
                   hashLong[h3] = current + 1;
                   if ( (matchIndex3 > dictStartIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
                       const BYTE* const matchEnd = matchIndex3 < prefixStartIndex ? dictEnd : iend;
                       const BYTE* const lowMatchPtr = matchIndex3 < prefixStartIndex ? dictStart : prefixStart;
                       mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, prefixStart) + 8;
                       ip++;
                       offset = current+1 - matchIndex3;
                       while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
                   } else {
                       const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
                       const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
                       mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
                       offset = current - matchIndex;
                       while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; }   /* catch up */
                   }
                   offset_2 = offset_1;
                   offset_1 = offset;
                   ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
   
               } else {
                   ip += ((ip-anchor) >> kSearchStrength) + 1;
                   continue;
           }   }
   
           /* move to next sequence start */
           ip += mLength;
           anchor = ip;
   
           if (ip <= ilimit) {
               /* Complementary insertion */
               /* done after iLimit test, as candidates could be > iend-8 */
               {   U32 const indexToInsert = current+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) {
                   U32 const current2 = (U32)(ip-base);
                   U32 const repIndex2 = current2 - offset_2;
                   const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
                   if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3)   /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
                       & (repIndex2 > dictStartIndex))
                     && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
                       const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
                       size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
                       U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
                       ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
                       hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
                       hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
                       ip += repLength2;
                       anchor = ip;
                       continue;
                   }
                   break;
       }   }   }
   
       /* save reps for next block */
       rep[0] = offset_1;
       rep[1] = offset_2;
   
       /* Return the last literals size */
       return (size_t)(iend - anchor);
   }
   
   
   size_t ZSTD_compressBlock_doubleFast_extDict(
           ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
           void const* src, size_t srcSize)
   {
       U32 const mls = ms->cParams.minMatch;
       switch(mls)
       {
       default: /* includes case 3 */
       case 4 :
           return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
       case 5 :
           return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
       case 6 :
           return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
       case 7 :
           return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
       }
   }

Cache object: 2192c1303afe20e6b3ece218d63278b7