969 lines
36 KiB
C
969 lines
36 KiB
C
/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#include "zstd_compress_internal.h" /* ZSTD_hashPtr, ZSTD_count, ZSTD_storeSeq */
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#include "zstd_fast.h"
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static
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ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
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void ZSTD_fillHashTableForCDict(ZSTD_matchState_t* ms,
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const void* const end,
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ZSTD_dictTableLoadMethod_e dtlm)
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{
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const ZSTD_compressionParameters* const cParams = &ms->cParams;
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U32* const hashTable = ms->hashTable;
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U32 const hBits = cParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS;
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U32 const mls = cParams->minMatch;
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const BYTE* const base = ms->window.base;
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const BYTE* ip = base + ms->nextToUpdate;
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const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
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const U32 fastHashFillStep = 3;
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/* Currently, we always use ZSTD_dtlm_full for filling CDict tables.
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* Feel free to remove this assert if there's a good reason! */
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assert(dtlm == ZSTD_dtlm_full);
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/* Always insert every fastHashFillStep position into the hash table.
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* Insert the other positions if their hash entry is empty.
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*/
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for ( ; ip + fastHashFillStep < iend + 2; ip += fastHashFillStep) {
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U32 const curr = (U32)(ip - base);
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{ size_t const hashAndTag = ZSTD_hashPtr(ip, hBits, mls);
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ZSTD_writeTaggedIndex(hashTable, hashAndTag, curr); }
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if (dtlm == ZSTD_dtlm_fast) continue;
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/* Only load extra positions for ZSTD_dtlm_full */
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{ U32 p;
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for (p = 1; p < fastHashFillStep; ++p) {
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size_t const hashAndTag = ZSTD_hashPtr(ip + p, hBits, mls);
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if (hashTable[hashAndTag >> ZSTD_SHORT_CACHE_TAG_BITS] == 0) { /* not yet filled */
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ZSTD_writeTaggedIndex(hashTable, hashAndTag, curr + p);
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} } } }
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}
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static
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ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
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void ZSTD_fillHashTableForCCtx(ZSTD_matchState_t* ms,
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const void* const end,
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ZSTD_dictTableLoadMethod_e dtlm)
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{
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const ZSTD_compressionParameters* const cParams = &ms->cParams;
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U32* const hashTable = ms->hashTable;
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U32 const hBits = cParams->hashLog;
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U32 const mls = cParams->minMatch;
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const BYTE* const base = ms->window.base;
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const BYTE* ip = base + ms->nextToUpdate;
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const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
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const U32 fastHashFillStep = 3;
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/* Currently, we always use ZSTD_dtlm_fast for filling CCtx tables.
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* Feel free to remove this assert if there's a good reason! */
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assert(dtlm == ZSTD_dtlm_fast);
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/* Always insert every fastHashFillStep position into the hash table.
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* Insert the other positions if their hash entry is empty.
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*/
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for ( ; ip + fastHashFillStep < iend + 2; ip += fastHashFillStep) {
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U32 const curr = (U32)(ip - base);
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size_t const hash0 = ZSTD_hashPtr(ip, hBits, mls);
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hashTable[hash0] = curr;
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if (dtlm == ZSTD_dtlm_fast) continue;
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/* Only load extra positions for ZSTD_dtlm_full */
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{ U32 p;
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for (p = 1; p < fastHashFillStep; ++p) {
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size_t const hash = ZSTD_hashPtr(ip + p, hBits, mls);
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if (hashTable[hash] == 0) { /* not yet filled */
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hashTable[hash] = curr + p;
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} } } }
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}
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void ZSTD_fillHashTable(ZSTD_matchState_t* ms,
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const void* const end,
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ZSTD_dictTableLoadMethod_e dtlm,
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ZSTD_tableFillPurpose_e tfp)
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{
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if (tfp == ZSTD_tfp_forCDict) {
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ZSTD_fillHashTableForCDict(ms, end, dtlm);
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} else {
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ZSTD_fillHashTableForCCtx(ms, end, dtlm);
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}
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}
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/**
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* If you squint hard enough (and ignore repcodes), the search operation at any
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* given position is broken into 4 stages:
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*
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* 1. Hash (map position to hash value via input read)
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* 2. Lookup (map hash val to index via hashtable read)
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* 3. Load (map index to value at that position via input read)
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* 4. Compare
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*
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* Each of these steps involves a memory read at an address which is computed
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* from the previous step. This means these steps must be sequenced and their
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* latencies are cumulative.
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*
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* Rather than do 1->2->3->4 sequentially for a single position before moving
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* onto the next, this implementation interleaves these operations across the
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* next few positions:
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*
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* R = Repcode Read & Compare
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* H = Hash
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* T = Table Lookup
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* M = Match Read & Compare
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*
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* Pos | Time -->
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* ----+-------------------
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* N | ... M
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* N+1 | ... TM
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* N+2 | R H T M
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* N+3 | H TM
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* N+4 | R H T M
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* N+5 | H ...
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* N+6 | R ...
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*
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* This is very much analogous to the pipelining of execution in a CPU. And just
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* like a CPU, we have to dump the pipeline when we find a match (i.e., take a
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* branch).
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*
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* When this happens, we throw away our current state, and do the following prep
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* to re-enter the loop:
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*
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* Pos | Time -->
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* ----+-------------------
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* N | H T
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* N+1 | H
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*
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* This is also the work we do at the beginning to enter the loop initially.
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*/
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FORCE_INLINE_TEMPLATE
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ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
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size_t ZSTD_compressBlock_fast_noDict_generic(
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ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
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void const* src, size_t srcSize,
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U32 const mls, U32 const hasStep)
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{
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const ZSTD_compressionParameters* const cParams = &ms->cParams;
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U32* const hashTable = ms->hashTable;
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U32 const hlog = cParams->hashLog;
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/* support stepSize of 0 */
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size_t const stepSize = hasStep ? (cParams->targetLength + !(cParams->targetLength) + 1) : 2;
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const BYTE* const base = ms->window.base;
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const BYTE* const istart = (const BYTE*)src;
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const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
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const U32 prefixStartIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
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const BYTE* const prefixStart = base + prefixStartIndex;
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const BYTE* const iend = istart + srcSize;
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const BYTE* const ilimit = iend - HASH_READ_SIZE;
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const BYTE* anchor = istart;
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const BYTE* ip0 = istart;
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const BYTE* ip1;
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const BYTE* ip2;
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const BYTE* ip3;
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U32 current0;
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U32 rep_offset1 = rep[0];
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U32 rep_offset2 = rep[1];
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U32 offsetSaved1 = 0, offsetSaved2 = 0;
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size_t hash0; /* hash for ip0 */
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size_t hash1; /* hash for ip1 */
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U32 idx; /* match idx for ip0 */
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U32 mval; /* src value at match idx */
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U32 offcode;
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const BYTE* match0;
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size_t mLength;
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/* ip0 and ip1 are always adjacent. The targetLength skipping and
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* uncompressibility acceleration is applied to every other position,
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* matching the behavior of #1562. step therefore represents the gap
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* between pairs of positions, from ip0 to ip2 or ip1 to ip3. */
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size_t step;
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const BYTE* nextStep;
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const size_t kStepIncr = (1 << (kSearchStrength - 1));
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DEBUGLOG(5, "ZSTD_compressBlock_fast_generic");
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ip0 += (ip0 == prefixStart);
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{ U32 const curr = (U32)(ip0 - base);
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U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, curr, cParams->windowLog);
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U32 const maxRep = curr - windowLow;
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if (rep_offset2 > maxRep) offsetSaved2 = rep_offset2, rep_offset2 = 0;
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if (rep_offset1 > maxRep) offsetSaved1 = rep_offset1, rep_offset1 = 0;
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}
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/* start each op */
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_start: /* Requires: ip0 */
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step = stepSize;
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nextStep = ip0 + kStepIncr;
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/* calculate positions, ip0 - anchor == 0, so we skip step calc */
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ip1 = ip0 + 1;
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ip2 = ip0 + step;
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ip3 = ip2 + 1;
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if (ip3 >= ilimit) {
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goto _cleanup;
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}
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hash0 = ZSTD_hashPtr(ip0, hlog, mls);
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hash1 = ZSTD_hashPtr(ip1, hlog, mls);
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idx = hashTable[hash0];
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do {
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/* load repcode match for ip[2]*/
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const U32 rval = MEM_read32(ip2 - rep_offset1);
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/* write back hash table entry */
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current0 = (U32)(ip0 - base);
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hashTable[hash0] = current0;
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/* check repcode at ip[2] */
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if ((MEM_read32(ip2) == rval) & (rep_offset1 > 0)) {
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ip0 = ip2;
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match0 = ip0 - rep_offset1;
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mLength = ip0[-1] == match0[-1];
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ip0 -= mLength;
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match0 -= mLength;
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offcode = REPCODE1_TO_OFFBASE;
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mLength += 4;
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/* First write next hash table entry; we've already calculated it.
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* This write is known to be safe because the ip1 is before the
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* repcode (ip2). */
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hashTable[hash1] = (U32)(ip1 - base);
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goto _match;
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}
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/* load match for ip[0] */
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if (idx >= prefixStartIndex) {
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mval = MEM_read32(base + idx);
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} else {
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mval = MEM_read32(ip0) ^ 1; /* guaranteed to not match. */
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}
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/* check match at ip[0] */
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if (MEM_read32(ip0) == mval) {
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/* found a match! */
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/* First write next hash table entry; we've already calculated it.
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* This write is known to be safe because the ip1 == ip0 + 1, so
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* we know we will resume searching after ip1 */
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hashTable[hash1] = (U32)(ip1 - base);
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goto _offset;
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}
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/* lookup ip[1] */
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idx = hashTable[hash1];
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/* hash ip[2] */
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hash0 = hash1;
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hash1 = ZSTD_hashPtr(ip2, hlog, mls);
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/* advance to next positions */
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ip0 = ip1;
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ip1 = ip2;
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ip2 = ip3;
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/* write back hash table entry */
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current0 = (U32)(ip0 - base);
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hashTable[hash0] = current0;
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/* load match for ip[0] */
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if (idx >= prefixStartIndex) {
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mval = MEM_read32(base + idx);
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} else {
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mval = MEM_read32(ip0) ^ 1; /* guaranteed to not match. */
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}
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/* check match at ip[0] */
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if (MEM_read32(ip0) == mval) {
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/* found a match! */
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/* first write next hash table entry; we've already calculated it */
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if (step <= 4) {
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/* We need to avoid writing an index into the hash table >= the
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* position at which we will pick up our searching after we've
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* taken this match.
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*
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* The minimum possible match has length 4, so the earliest ip0
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* can be after we take this match will be the current ip0 + 4.
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* ip1 is ip0 + step - 1. If ip1 is >= ip0 + 4, we can't safely
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* write this position.
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*/
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hashTable[hash1] = (U32)(ip1 - base);
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}
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goto _offset;
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}
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/* lookup ip[1] */
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idx = hashTable[hash1];
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/* hash ip[2] */
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hash0 = hash1;
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hash1 = ZSTD_hashPtr(ip2, hlog, mls);
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/* advance to next positions */
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ip0 = ip1;
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ip1 = ip2;
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ip2 = ip0 + step;
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ip3 = ip1 + step;
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/* calculate step */
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if (ip2 >= nextStep) {
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step++;
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PREFETCH_L1(ip1 + 64);
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PREFETCH_L1(ip1 + 128);
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nextStep += kStepIncr;
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}
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} while (ip3 < ilimit);
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_cleanup:
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/* Note that there are probably still a couple positions we could search.
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* However, it seems to be a meaningful performance hit to try to search
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* them. So let's not. */
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/* When the repcodes are outside of the prefix, we set them to zero before the loop.
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* When the offsets are still zero, we need to restore them after the block to have a correct
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* repcode history. If only one offset was invalid, it is easy. The tricky case is when both
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* offsets were invalid. We need to figure out which offset to refill with.
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* - If both offsets are zero they are in the same order.
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* - If both offsets are non-zero, we won't restore the offsets from `offsetSaved[12]`.
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* - If only one is zero, we need to decide which offset to restore.
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* - If rep_offset1 is non-zero, then rep_offset2 must be offsetSaved1.
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* - It is impossible for rep_offset2 to be non-zero.
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*
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* So if rep_offset1 started invalid (offsetSaved1 != 0) and became valid (rep_offset1 != 0), then
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* set rep[0] = rep_offset1 and rep[1] = offsetSaved1.
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*/
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offsetSaved2 = ((offsetSaved1 != 0) && (rep_offset1 != 0)) ? offsetSaved1 : offsetSaved2;
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/* save reps for next block */
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rep[0] = rep_offset1 ? rep_offset1 : offsetSaved1;
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rep[1] = rep_offset2 ? rep_offset2 : offsetSaved2;
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/* Return the last literals size */
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return (size_t)(iend - anchor);
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_offset: /* Requires: ip0, idx */
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/* Compute the offset code. */
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match0 = base + idx;
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rep_offset2 = rep_offset1;
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rep_offset1 = (U32)(ip0-match0);
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offcode = OFFSET_TO_OFFBASE(rep_offset1);
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mLength = 4;
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/* Count the backwards match length. */
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while (((ip0>anchor) & (match0>prefixStart)) && (ip0[-1] == match0[-1])) {
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ip0--;
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match0--;
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mLength++;
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}
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_match: /* Requires: ip0, match0, offcode */
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/* Count the forward length. */
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mLength += ZSTD_count(ip0 + mLength, match0 + mLength, iend);
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ZSTD_storeSeq(seqStore, (size_t)(ip0 - anchor), anchor, iend, offcode, mLength);
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ip0 += mLength;
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anchor = ip0;
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/* Fill table and check for immediate repcode. */
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if (ip0 <= ilimit) {
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/* Fill Table */
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assert(base+current0+2 > istart); /* check base overflow */
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hashTable[ZSTD_hashPtr(base+current0+2, hlog, mls)] = current0+2; /* here because current+2 could be > iend-8 */
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hashTable[ZSTD_hashPtr(ip0-2, hlog, mls)] = (U32)(ip0-2-base);
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if (rep_offset2 > 0) { /* rep_offset2==0 means rep_offset2 is invalidated */
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while ( (ip0 <= ilimit) && (MEM_read32(ip0) == MEM_read32(ip0 - rep_offset2)) ) {
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/* store sequence */
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size_t const rLength = ZSTD_count(ip0+4, ip0+4-rep_offset2, iend) + 4;
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{ U32 const tmpOff = rep_offset2; rep_offset2 = rep_offset1; rep_offset1 = tmpOff; } /* swap rep_offset2 <=> rep_offset1 */
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hashTable[ZSTD_hashPtr(ip0, hlog, mls)] = (U32)(ip0-base);
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ip0 += rLength;
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ZSTD_storeSeq(seqStore, 0 /*litLen*/, anchor, iend, REPCODE1_TO_OFFBASE, rLength);
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anchor = ip0;
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continue; /* faster when present (confirmed on gcc-8) ... (?) */
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} } }
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goto _start;
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}
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#define ZSTD_GEN_FAST_FN(dictMode, mls, step) \
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static size_t ZSTD_compressBlock_fast_##dictMode##_##mls##_##step( \
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ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], \
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void const* src, size_t srcSize) \
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{ \
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return ZSTD_compressBlock_fast_##dictMode##_generic(ms, seqStore, rep, src, srcSize, mls, step); \
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}
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ZSTD_GEN_FAST_FN(noDict, 4, 1)
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ZSTD_GEN_FAST_FN(noDict, 5, 1)
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ZSTD_GEN_FAST_FN(noDict, 6, 1)
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ZSTD_GEN_FAST_FN(noDict, 7, 1)
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ZSTD_GEN_FAST_FN(noDict, 4, 0)
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ZSTD_GEN_FAST_FN(noDict, 5, 0)
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ZSTD_GEN_FAST_FN(noDict, 6, 0)
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ZSTD_GEN_FAST_FN(noDict, 7, 0)
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size_t ZSTD_compressBlock_fast(
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ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
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void const* src, size_t srcSize)
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{
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U32 const mls = ms->cParams.minMatch;
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assert(ms->dictMatchState == NULL);
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if (ms->cParams.targetLength > 1) {
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switch(mls)
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{
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default: /* includes case 3 */
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case 4 :
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return ZSTD_compressBlock_fast_noDict_4_1(ms, seqStore, rep, src, srcSize);
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case 5 :
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return ZSTD_compressBlock_fast_noDict_5_1(ms, seqStore, rep, src, srcSize);
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case 6 :
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return ZSTD_compressBlock_fast_noDict_6_1(ms, seqStore, rep, src, srcSize);
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case 7 :
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return ZSTD_compressBlock_fast_noDict_7_1(ms, seqStore, rep, src, srcSize);
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}
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} else {
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switch(mls)
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{
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default: /* includes case 3 */
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case 4 :
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return ZSTD_compressBlock_fast_noDict_4_0(ms, seqStore, rep, src, srcSize);
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case 5 :
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return ZSTD_compressBlock_fast_noDict_5_0(ms, seqStore, rep, src, srcSize);
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case 6 :
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return ZSTD_compressBlock_fast_noDict_6_0(ms, seqStore, rep, src, srcSize);
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case 7 :
|
|
return ZSTD_compressBlock_fast_noDict_7_0(ms, seqStore, rep, src, srcSize);
|
|
}
|
|
|
|
}
|
|
}
|
|
|
|
FORCE_INLINE_TEMPLATE
|
|
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
|
size_t ZSTD_compressBlock_fast_dictMatchState_generic(
|
|
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
|
|
void const* src, size_t srcSize, U32 const mls, U32 const hasStep)
|
|
{
|
|
const ZSTD_compressionParameters* const cParams = &ms->cParams;
|
|
U32* const hashTable = ms->hashTable;
|
|
U32 const hlog = cParams->hashLog;
|
|
/* support stepSize of 0 */
|
|
U32 const stepSize = cParams->targetLength + !(cParams->targetLength);
|
|
const BYTE* const base = ms->window.base;
|
|
const BYTE* const istart = (const BYTE*)src;
|
|
const BYTE* ip0 = istart;
|
|
const BYTE* ip1 = ip0 + stepSize; /* we assert below that stepSize >= 1 */
|
|
const BYTE* anchor = istart;
|
|
const U32 prefixStartIndex = ms->window.dictLimit;
|
|
const BYTE* const prefixStart = base + prefixStartIndex;
|
|
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 dictHashTable = dms->hashTable;
|
|
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 = prefixStartIndex - (U32)(dictEnd - dictBase);
|
|
const U32 dictAndPrefixLength = (U32)(istart - prefixStart + dictEnd - dictStart);
|
|
const U32 dictHBits = dictCParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS;
|
|
|
|
/* if a dictionary is still attached, it necessarily means that
|
|
* it is within window size. So we just check it. */
|
|
const U32 maxDistance = 1U << cParams->windowLog;
|
|
const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
|
|
assert(endIndex - prefixStartIndex <= maxDistance);
|
|
(void)maxDistance; (void)endIndex; /* these variables are not used when assert() is disabled */
|
|
|
|
(void)hasStep; /* not currently specialized on whether it's accelerated */
|
|
|
|
/* ensure there will be no underflow
|
|
* when translating a dict index into a local index */
|
|
assert(prefixStartIndex >= (U32)(dictEnd - dictBase));
|
|
|
|
if (ms->prefetchCDictTables) {
|
|
size_t const hashTableBytes = (((size_t)1) << dictCParams->hashLog) * sizeof(U32);
|
|
PREFETCH_AREA(dictHashTable, hashTableBytes);
|
|
}
|
|
|
|
/* init */
|
|
DEBUGLOG(5, "ZSTD_compressBlock_fast_dictMatchState_generic");
|
|
ip0 += (dictAndPrefixLength == 0);
|
|
/* dictMatchState repCode checks don't currently handle repCode == 0
|
|
* disabling. */
|
|
assert(offset_1 <= dictAndPrefixLength);
|
|
assert(offset_2 <= dictAndPrefixLength);
|
|
|
|
/* Outer search loop */
|
|
assert(stepSize >= 1);
|
|
while (ip1 <= ilimit) { /* repcode check at (ip0 + 1) is safe because ip0 < ip1 */
|
|
size_t mLength;
|
|
size_t hash0 = ZSTD_hashPtr(ip0, hlog, mls);
|
|
|
|
size_t const dictHashAndTag0 = ZSTD_hashPtr(ip0, dictHBits, mls);
|
|
U32 dictMatchIndexAndTag = dictHashTable[dictHashAndTag0 >> ZSTD_SHORT_CACHE_TAG_BITS];
|
|
int dictTagsMatch = ZSTD_comparePackedTags(dictMatchIndexAndTag, dictHashAndTag0);
|
|
|
|
U32 matchIndex = hashTable[hash0];
|
|
U32 curr = (U32)(ip0 - base);
|
|
size_t step = stepSize;
|
|
const size_t kStepIncr = 1 << kSearchStrength;
|
|
const BYTE* nextStep = ip0 + kStepIncr;
|
|
|
|
/* Inner search loop */
|
|
while (1) {
|
|
const BYTE* match = base + matchIndex;
|
|
const U32 repIndex = curr + 1 - offset_1;
|
|
const BYTE* repMatch = (repIndex < prefixStartIndex) ?
|
|
dictBase + (repIndex - dictIndexDelta) :
|
|
base + repIndex;
|
|
const size_t hash1 = ZSTD_hashPtr(ip1, hlog, mls);
|
|
size_t const dictHashAndTag1 = ZSTD_hashPtr(ip1, dictHBits, mls);
|
|
hashTable[hash0] = curr; /* update hash table */
|
|
|
|
if (((U32) ((prefixStartIndex - 1) - repIndex) >=
|
|
3) /* intentional underflow : ensure repIndex isn't overlapping dict + prefix */
|
|
&& (MEM_read32(repMatch) == MEM_read32(ip0 + 1))) {
|
|
const BYTE* const repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
|
|
mLength = ZSTD_count_2segments(ip0 + 1 + 4, repMatch + 4, iend, repMatchEnd, prefixStart) + 4;
|
|
ip0++;
|
|
ZSTD_storeSeq(seqStore, (size_t) (ip0 - anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
|
|
break;
|
|
}
|
|
|
|
if (dictTagsMatch) {
|
|
/* Found a possible dict match */
|
|
const U32 dictMatchIndex = dictMatchIndexAndTag >> ZSTD_SHORT_CACHE_TAG_BITS;
|
|
const BYTE* dictMatch = dictBase + dictMatchIndex;
|
|
if (dictMatchIndex > dictStartIndex &&
|
|
MEM_read32(dictMatch) == MEM_read32(ip0)) {
|
|
/* To replicate extDict parse behavior, we only use dict matches when the normal matchIndex is invalid */
|
|
if (matchIndex <= prefixStartIndex) {
|
|
U32 const offset = (U32) (curr - dictMatchIndex - dictIndexDelta);
|
|
mLength = ZSTD_count_2segments(ip0 + 4, dictMatch + 4, iend, dictEnd, prefixStart) + 4;
|
|
while (((ip0 > anchor) & (dictMatch > dictStart))
|
|
&& (ip0[-1] == dictMatch[-1])) {
|
|
ip0--;
|
|
dictMatch--;
|
|
mLength++;
|
|
} /* catch up */
|
|
offset_2 = offset_1;
|
|
offset_1 = offset;
|
|
ZSTD_storeSeq(seqStore, (size_t) (ip0 - anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (matchIndex > prefixStartIndex && MEM_read32(match) == MEM_read32(ip0)) {
|
|
/* found a regular match */
|
|
U32 const offset = (U32) (ip0 - match);
|
|
mLength = ZSTD_count(ip0 + 4, match + 4, iend) + 4;
|
|
while (((ip0 > anchor) & (match > prefixStart))
|
|
&& (ip0[-1] == match[-1])) {
|
|
ip0--;
|
|
match--;
|
|
mLength++;
|
|
} /* catch up */
|
|
offset_2 = offset_1;
|
|
offset_1 = offset;
|
|
ZSTD_storeSeq(seqStore, (size_t) (ip0 - anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
|
|
break;
|
|
}
|
|
|
|
/* Prepare for next iteration */
|
|
dictMatchIndexAndTag = dictHashTable[dictHashAndTag1 >> ZSTD_SHORT_CACHE_TAG_BITS];
|
|
dictTagsMatch = ZSTD_comparePackedTags(dictMatchIndexAndTag, dictHashAndTag1);
|
|
matchIndex = hashTable[hash1];
|
|
|
|
if (ip1 >= nextStep) {
|
|
step++;
|
|
nextStep += kStepIncr;
|
|
}
|
|
ip0 = ip1;
|
|
ip1 = ip1 + step;
|
|
if (ip1 > ilimit) goto _cleanup;
|
|
|
|
curr = (U32)(ip0 - base);
|
|
hash0 = hash1;
|
|
} /* end inner search loop */
|
|
|
|
/* match found */
|
|
assert(mLength);
|
|
ip0 += mLength;
|
|
anchor = ip0;
|
|
|
|
if (ip0 <= ilimit) {
|
|
/* Fill Table */
|
|
assert(base+curr+2 > istart); /* check base overflow */
|
|
hashTable[ZSTD_hashPtr(base+curr+2, hlog, mls)] = curr+2; /* here because curr+2 could be > iend-8 */
|
|
hashTable[ZSTD_hashPtr(ip0-2, hlog, mls)] = (U32)(ip0-2-base);
|
|
|
|
/* check immediate repcode */
|
|
while (ip0 <= ilimit) {
|
|
U32 const current2 = (U32)(ip0-base);
|
|
U32 const repIndex2 = current2 - offset_2;
|
|
const BYTE* repMatch2 = repIndex2 < prefixStartIndex ?
|
|
dictBase - dictIndexDelta + repIndex2 :
|
|
base + repIndex2;
|
|
if ( ((U32)((prefixStartIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
|
|
&& (MEM_read32(repMatch2) == MEM_read32(ip0))) {
|
|
const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
|
|
size_t const repLength2 = ZSTD_count_2segments(ip0+4, repMatch2+4, iend, repEnd2, prefixStart) + 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);
|
|
hashTable[ZSTD_hashPtr(ip0, hlog, mls)] = current2;
|
|
ip0 += repLength2;
|
|
anchor = ip0;
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Prepare for next iteration */
|
|
assert(ip0 == anchor);
|
|
ip1 = ip0 + stepSize;
|
|
}
|
|
|
|
_cleanup:
|
|
/* 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_FAST_FN(dictMatchState, 4, 0)
|
|
ZSTD_GEN_FAST_FN(dictMatchState, 5, 0)
|
|
ZSTD_GEN_FAST_FN(dictMatchState, 6, 0)
|
|
ZSTD_GEN_FAST_FN(dictMatchState, 7, 0)
|
|
|
|
size_t ZSTD_compressBlock_fast_dictMatchState(
|
|
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
|
|
void const* src, size_t srcSize)
|
|
{
|
|
U32 const mls = ms->cParams.minMatch;
|
|
assert(ms->dictMatchState != NULL);
|
|
switch(mls)
|
|
{
|
|
default: /* includes case 3 */
|
|
case 4 :
|
|
return ZSTD_compressBlock_fast_dictMatchState_4_0(ms, seqStore, rep, src, srcSize);
|
|
case 5 :
|
|
return ZSTD_compressBlock_fast_dictMatchState_5_0(ms, seqStore, rep, src, srcSize);
|
|
case 6 :
|
|
return ZSTD_compressBlock_fast_dictMatchState_6_0(ms, seqStore, rep, src, srcSize);
|
|
case 7 :
|
|
return ZSTD_compressBlock_fast_dictMatchState_7_0(ms, seqStore, rep, src, srcSize);
|
|
}
|
|
}
|
|
|
|
|
|
static
|
|
ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
|
|
size_t ZSTD_compressBlock_fast_extDict_generic(
|
|
ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
|
|
void const* src, size_t srcSize, U32 const mls, U32 const hasStep)
|
|
{
|
|
const ZSTD_compressionParameters* const cParams = &ms->cParams;
|
|
U32* const hashTable = ms->hashTable;
|
|
U32 const hlog = cParams->hashLog;
|
|
/* support stepSize of 0 */
|
|
size_t const stepSize = cParams->targetLength + !(cParams->targetLength) + 1;
|
|
const BYTE* const base = ms->window.base;
|
|
const BYTE* const dictBase = ms->window.dictBase;
|
|
const BYTE* const istart = (const BYTE*)src;
|
|
const BYTE* anchor = istart;
|
|
const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
|
|
const U32 lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
|
|
const U32 dictStartIndex = lowLimit;
|
|
const BYTE* const dictStart = dictBase + dictStartIndex;
|
|
const U32 dictLimit = ms->window.dictLimit;
|
|
const U32 prefixStartIndex = dictLimit < lowLimit ? lowLimit : dictLimit;
|
|
const BYTE* const prefixStart = base + prefixStartIndex;
|
|
const BYTE* const dictEnd = dictBase + prefixStartIndex;
|
|
const BYTE* const iend = istart + srcSize;
|
|
const BYTE* const ilimit = iend - 8;
|
|
U32 offset_1=rep[0], offset_2=rep[1];
|
|
U32 offsetSaved1 = 0, offsetSaved2 = 0;
|
|
|
|
const BYTE* ip0 = istart;
|
|
const BYTE* ip1;
|
|
const BYTE* ip2;
|
|
const BYTE* ip3;
|
|
U32 current0;
|
|
|
|
|
|
size_t hash0; /* hash for ip0 */
|
|
size_t hash1; /* hash for ip1 */
|
|
U32 idx; /* match idx for ip0 */
|
|
const BYTE* idxBase; /* base pointer for idx */
|
|
|
|
U32 offcode;
|
|
const BYTE* match0;
|
|
size_t mLength;
|
|
const BYTE* matchEnd = 0; /* initialize to avoid warning, assert != 0 later */
|
|
|
|
size_t step;
|
|
const BYTE* nextStep;
|
|
const size_t kStepIncr = (1 << (kSearchStrength - 1));
|
|
|
|
(void)hasStep; /* not currently specialized on whether it's accelerated */
|
|
|
|
DEBUGLOG(5, "ZSTD_compressBlock_fast_extDict_generic (offset_1=%u)", offset_1);
|
|
|
|
/* switch to "regular" variant if extDict is invalidated due to maxDistance */
|
|
if (prefixStartIndex == dictStartIndex)
|
|
return ZSTD_compressBlock_fast(ms, seqStore, rep, src, srcSize);
|
|
|
|
{ U32 const curr = (U32)(ip0 - base);
|
|
U32 const maxRep = curr - dictStartIndex;
|
|
if (offset_2 >= maxRep) offsetSaved2 = offset_2, offset_2 = 0;
|
|
if (offset_1 >= maxRep) offsetSaved1 = offset_1, offset_1 = 0;
|
|
}
|
|
|
|
/* start each op */
|
|
_start: /* Requires: ip0 */
|
|
|
|
step = stepSize;
|
|
nextStep = ip0 + kStepIncr;
|
|
|
|
/* calculate positions, ip0 - anchor == 0, so we skip step calc */
|
|
ip1 = ip0 + 1;
|
|
ip2 = ip0 + step;
|
|
ip3 = ip2 + 1;
|
|
|
|
if (ip3 >= ilimit) {
|
|
goto _cleanup;
|
|
}
|
|
|
|
hash0 = ZSTD_hashPtr(ip0, hlog, mls);
|
|
hash1 = ZSTD_hashPtr(ip1, hlog, mls);
|
|
|
|
idx = hashTable[hash0];
|
|
idxBase = idx < prefixStartIndex ? dictBase : base;
|
|
|
|
do {
|
|
{ /* load repcode match for ip[2] */
|
|
U32 const current2 = (U32)(ip2 - base);
|
|
U32 const repIndex = current2 - offset_1;
|
|
const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
|
|
U32 rval;
|
|
if ( ((U32)(prefixStartIndex - repIndex) >= 4) /* intentional underflow */
|
|
& (offset_1 > 0) ) {
|
|
rval = MEM_read32(repBase + repIndex);
|
|
} else {
|
|
rval = MEM_read32(ip2) ^ 1; /* guaranteed to not match. */
|
|
}
|
|
|
|
/* write back hash table entry */
|
|
current0 = (U32)(ip0 - base);
|
|
hashTable[hash0] = current0;
|
|
|
|
/* check repcode at ip[2] */
|
|
if (MEM_read32(ip2) == rval) {
|
|
ip0 = ip2;
|
|
match0 = repBase + repIndex;
|
|
matchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
|
|
assert((match0 != prefixStart) & (match0 != dictStart));
|
|
mLength = ip0[-1] == match0[-1];
|
|
ip0 -= mLength;
|
|
match0 -= mLength;
|
|
offcode = REPCODE1_TO_OFFBASE;
|
|
mLength += 4;
|
|
goto _match;
|
|
} }
|
|
|
|
{ /* load match for ip[0] */
|
|
U32 const mval = idx >= dictStartIndex ?
|
|
MEM_read32(idxBase + idx) :
|
|
MEM_read32(ip0) ^ 1; /* guaranteed not to match */
|
|
|
|
/* check match at ip[0] */
|
|
if (MEM_read32(ip0) == mval) {
|
|
/* found a match! */
|
|
goto _offset;
|
|
} }
|
|
|
|
/* lookup ip[1] */
|
|
idx = hashTable[hash1];
|
|
idxBase = idx < prefixStartIndex ? dictBase : base;
|
|
|
|
/* hash ip[2] */
|
|
hash0 = hash1;
|
|
hash1 = ZSTD_hashPtr(ip2, hlog, mls);
|
|
|
|
/* advance to next positions */
|
|
ip0 = ip1;
|
|
ip1 = ip2;
|
|
ip2 = ip3;
|
|
|
|
/* write back hash table entry */
|
|
current0 = (U32)(ip0 - base);
|
|
hashTable[hash0] = current0;
|
|
|
|
{ /* load match for ip[0] */
|
|
U32 const mval = idx >= dictStartIndex ?
|
|
MEM_read32(idxBase + idx) :
|
|
MEM_read32(ip0) ^ 1; /* guaranteed not to match */
|
|
|
|
/* check match at ip[0] */
|
|
if (MEM_read32(ip0) == mval) {
|
|
/* found a match! */
|
|
goto _offset;
|
|
} }
|
|
|
|
/* lookup ip[1] */
|
|
idx = hashTable[hash1];
|
|
idxBase = idx < prefixStartIndex ? dictBase : base;
|
|
|
|
/* hash ip[2] */
|
|
hash0 = hash1;
|
|
hash1 = ZSTD_hashPtr(ip2, hlog, mls);
|
|
|
|
/* advance to next positions */
|
|
ip0 = ip1;
|
|
ip1 = ip2;
|
|
ip2 = ip0 + step;
|
|
ip3 = ip1 + step;
|
|
|
|
/* calculate step */
|
|
if (ip2 >= nextStep) {
|
|
step++;
|
|
PREFETCH_L1(ip1 + 64);
|
|
PREFETCH_L1(ip1 + 128);
|
|
nextStep += kStepIncr;
|
|
}
|
|
} while (ip3 < ilimit);
|
|
|
|
_cleanup:
|
|
/* Note that there are probably still a couple positions we could search.
|
|
* However, it seems to be a meaningful performance hit to try to search
|
|
* them. So let's not. */
|
|
|
|
/* 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);
|
|
|
|
_offset: /* Requires: ip0, idx, idxBase */
|
|
|
|
/* Compute the offset code. */
|
|
{ U32 const offset = current0 - idx;
|
|
const BYTE* const lowMatchPtr = idx < prefixStartIndex ? dictStart : prefixStart;
|
|
matchEnd = idx < prefixStartIndex ? dictEnd : iend;
|
|
match0 = idxBase + idx;
|
|
offset_2 = offset_1;
|
|
offset_1 = offset;
|
|
offcode = OFFSET_TO_OFFBASE(offset);
|
|
mLength = 4;
|
|
|
|
/* Count the backwards match length. */
|
|
while (((ip0>anchor) & (match0>lowMatchPtr)) && (ip0[-1] == match0[-1])) {
|
|
ip0--;
|
|
match0--;
|
|
mLength++;
|
|
} }
|
|
|
|
_match: /* Requires: ip0, match0, offcode, matchEnd */
|
|
|
|
/* Count the forward length. */
|
|
assert(matchEnd != 0);
|
|
mLength += ZSTD_count_2segments(ip0 + mLength, match0 + mLength, iend, matchEnd, prefixStart);
|
|
|
|
ZSTD_storeSeq(seqStore, (size_t)(ip0 - anchor), anchor, iend, offcode, mLength);
|
|
|
|
ip0 += mLength;
|
|
anchor = ip0;
|
|
|
|
/* write next hash table entry */
|
|
if (ip1 < ip0) {
|
|
hashTable[hash1] = (U32)(ip1 - base);
|
|
}
|
|
|
|
/* Fill table and check for immediate repcode. */
|
|
if (ip0 <= ilimit) {
|
|
/* Fill Table */
|
|
assert(base+current0+2 > istart); /* check base overflow */
|
|
hashTable[ZSTD_hashPtr(base+current0+2, hlog, mls)] = current0+2; /* here because current+2 could be > iend-8 */
|
|
hashTable[ZSTD_hashPtr(ip0-2, hlog, mls)] = (U32)(ip0-2-base);
|
|
|
|
while (ip0 <= ilimit) {
|
|
U32 const repIndex2 = (U32)(ip0-base) - offset_2;
|
|
const BYTE* const repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
|
|
if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) & (offset_2 > 0)) /* intentional underflow */
|
|
&& (MEM_read32(repMatch2) == MEM_read32(ip0)) ) {
|
|
const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
|
|
size_t const repLength2 = ZSTD_count_2segments(ip0+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 /*litlen*/, anchor, iend, REPCODE1_TO_OFFBASE, repLength2);
|
|
hashTable[ZSTD_hashPtr(ip0, hlog, mls)] = (U32)(ip0-base);
|
|
ip0 += repLength2;
|
|
anchor = ip0;
|
|
continue;
|
|
}
|
|
break;
|
|
} }
|
|
|
|
goto _start;
|
|
}
|
|
|
|
ZSTD_GEN_FAST_FN(extDict, 4, 0)
|
|
ZSTD_GEN_FAST_FN(extDict, 5, 0)
|
|
ZSTD_GEN_FAST_FN(extDict, 6, 0)
|
|
ZSTD_GEN_FAST_FN(extDict, 7, 0)
|
|
|
|
size_t ZSTD_compressBlock_fast_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;
|
|
assert(ms->dictMatchState == NULL);
|
|
switch(mls)
|
|
{
|
|
default: /* includes case 3 */
|
|
case 4 :
|
|
return ZSTD_compressBlock_fast_extDict_4_0(ms, seqStore, rep, src, srcSize);
|
|
case 5 :
|
|
return ZSTD_compressBlock_fast_extDict_5_0(ms, seqStore, rep, src, srcSize);
|
|
case 6 :
|
|
return ZSTD_compressBlock_fast_extDict_6_0(ms, seqStore, rep, src, srcSize);
|
|
case 7 :
|
|
return ZSTD_compressBlock_fast_extDict_7_0(ms, seqStore, rep, src, srcSize);
|
|
}
|
|
}
|