/*

 * 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;

        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) {

                U32 const current2 = (U32)(ip-base);

                U32 const repIndex2 = current2 - offset_2;

                const BYTE* repMatch2 = repIndex2 < prefixLowestIndex ?

                        dictBase + repIndex2 - dictIndexDelta :

                        base + repIndex2;

                if ( (ZSTD_index_overlap_check(prefixLowestIndex, repIndex2))

                   && (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, REPCODE1_TO_OFFBASE, repLength2);

                    hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;

                    hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;

                    ip += repLength2;

                    anchor = ip;

                    continue;

                }

                break;

            }

        }

    }   /* while (ip < ilimit) */

    /* save reps for next block */

    rep[0] = offset_1;

    rep[1] = offset_2;

    /* Return the last literals size */

    return (size_t)(iend - anchor);

}

#define ZSTD_GEN_DFAST_FN(dictMode, mls)                                                                 \

    static size_t ZSTD_compressBlock_doubleFast_##dictMode##_##mls(                                      \

            ZSTD_MatchState_t* ms, SeqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],                          \

            void const* src, size_t srcSize)                                                             \

    {                                                                                                    \

        return ZSTD_compressBlock_doubleFast_##dictMode##_generic(ms, seqStore, rep, src, srcSize, mls); \

    }

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_noDict_4

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_noDict_5

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_noDict_6

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_noDict_7

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_dictMatchState_4

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_dictMatchState_5

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_dictMatchState_6

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_dictMatchState_7

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_extDict_4

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_extDict_5

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_extDict_6

Unexecuted instantiation: zstd_double_fast.c:ZSTD_compressBlock_doubleFast_extDict_7

ZSTD_GEN_DFAST_FN(noDict, 4)

ZSTD_GEN_DFAST_FN(noDict, 5)

ZSTD_GEN_DFAST_FN(noDict, 6)

ZSTD_GEN_DFAST_FN(noDict, 7)

ZSTD_GEN_DFAST_FN(dictMatchState, 4)

ZSTD_GEN_DFAST_FN(dictMatchState, 5)

ZSTD_GEN_DFAST_FN(dictMatchState, 6)

ZSTD_GEN_DFAST_FN(dictMatchState, 7)

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_noDict_4(ms, seqStore, rep, src, srcSize);

    case 5 :

        return ZSTD_compressBlock_doubleFast_noDict_5(ms, seqStore, rep, src, srcSize);

    case 6 :

        return ZSTD_compressBlock_doubleFast_noDict_6(ms, seqStore, rep, src, srcSize);

    case 7 :

        return ZSTD_compressBlock_doubleFast_noDict_7(ms, seqStore, rep, src, srcSize);

    }

}

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_dictMatchState_4(ms, seqStore, rep, src, srcSize);

    case 5 :

        return ZSTD_compressBlock_doubleFast_dictMatchState_5(ms, seqStore, rep, src, srcSize);

    case 6 :

        return ZSTD_compressBlock_doubleFast_dictMatchState_6(ms, seqStore, rep, src, srcSize);

    case 7 :

        return ZSTD_compressBlock_doubleFast_dictMatchState_7(ms, seqStore, rep, src, srcSize);

    }

}

static

ZSTD_ALLOW_POINTER_OVERFLOW_ATTR

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(ms, seqStore, rep, src, srcSize);

    /* 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 curr = (U32)(ip-base);

        const U32 repIndex = curr + 1 - offset_1;   /* offset_1 expected <= curr +1 */

        const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;

        const BYTE* const repMatch = repBase + repIndex;

        size_t mLength;

        hashSmall[hSmall] = hashLong[hLong] = curr;   /* update hash table */

        if (((ZSTD_index_overlap_check(prefixStartIndex, repIndex))

            & (offset_1 <= curr+1 - dictStartIndex)) /* note: we are searching at curr+1 */

          && (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, REPCODE1_TO_OFFBASE, mLength);

        } 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 = curr - 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_TO_OFFBASE(offset), mLength);

            } 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] = curr + 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 = curr+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 = curr - 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_TO_OFFBASE(offset), mLength);

            } 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 = 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) {

                U32 const current2 = (U32)(ip-base);

                U32 const repIndex2 = current2 - offset_2;

                const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;

                if ( ((ZSTD_index_overlap_check(prefixStartIndex, repIndex2))

                    & (offset_2 <= current2 - 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, REPCODE1_TO_OFFBASE, repLength2);

                    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);

}

ZSTD_GEN_DFAST_FN(extDict, 4)

ZSTD_GEN_DFAST_FN(extDict, 5)

ZSTD_GEN_DFAST_FN(extDict, 6)

ZSTD_GEN_DFAST_FN(extDict, 7)

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_4(ms, seqStore, rep, src, srcSize);

    case 5 :

        return ZSTD_compressBlock_doubleFast_extDict_5(ms, seqStore, rep, src, srcSize);

    case 6 :

        return ZSTD_compressBlock_doubleFast_extDict_6(ms, seqStore, rep, src, srcSize);

    case 7 :

        return ZSTD_compressBlock_doubleFast_extDict_7(ms, seqStore, rep, src, srcSize);

    }

}

#endif /* ZSTD_EXCLUDE_DFAST_BLOCK_COMPRESSOR */