xref: /dflybsd-src/contrib/zstd/lib/compress/zstd_double_fast.c (revision a28cd43d19e8b720a6c852a4bbc5ae147a26165a)
1a28cd43dSSascha Wildner /*
2a28cd43dSSascha Wildner  * Copyright (c) 2016-2020, Yann Collet, Facebook, Inc.
3a28cd43dSSascha Wildner  * All rights reserved.
4a28cd43dSSascha Wildner  *
5a28cd43dSSascha Wildner  * This source code is licensed under both the BSD-style license (found in the
6a28cd43dSSascha Wildner  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7a28cd43dSSascha Wildner  * in the COPYING file in the root directory of this source tree).
8a28cd43dSSascha Wildner  * You may select, at your option, one of the above-listed licenses.
9a28cd43dSSascha Wildner  */
10a28cd43dSSascha Wildner 
11a28cd43dSSascha Wildner #include "zstd_compress_internal.h"
12a28cd43dSSascha Wildner #include "zstd_double_fast.h"
13a28cd43dSSascha Wildner 
14a28cd43dSSascha Wildner 
ZSTD_fillDoubleHashTable(ZSTD_matchState_t * ms,void const * end,ZSTD_dictTableLoadMethod_e dtlm)15a28cd43dSSascha Wildner void ZSTD_fillDoubleHashTable(ZSTD_matchState_t* ms,
16a28cd43dSSascha Wildner                               void const* end, ZSTD_dictTableLoadMethod_e dtlm)
17a28cd43dSSascha Wildner {
18a28cd43dSSascha Wildner     const ZSTD_compressionParameters* const cParams = &ms->cParams;
19a28cd43dSSascha Wildner     U32* const hashLarge = ms->hashTable;
20a28cd43dSSascha Wildner     U32  const hBitsL = cParams->hashLog;
21a28cd43dSSascha Wildner     U32  const mls = cParams->minMatch;
22a28cd43dSSascha Wildner     U32* const hashSmall = ms->chainTable;
23a28cd43dSSascha Wildner     U32  const hBitsS = cParams->chainLog;
24a28cd43dSSascha Wildner     const BYTE* const base = ms->window.base;
25a28cd43dSSascha Wildner     const BYTE* ip = base + ms->nextToUpdate;
26a28cd43dSSascha Wildner     const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
27a28cd43dSSascha Wildner     const U32 fastHashFillStep = 3;
28a28cd43dSSascha Wildner 
29a28cd43dSSascha Wildner     /* Always insert every fastHashFillStep position into the hash tables.
30a28cd43dSSascha Wildner      * Insert the other positions into the large hash table if their entry
31a28cd43dSSascha Wildner      * is empty.
32a28cd43dSSascha Wildner      */
33a28cd43dSSascha Wildner     for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
34a28cd43dSSascha Wildner         U32 const curr = (U32)(ip - base);
35a28cd43dSSascha Wildner         U32 i;
36a28cd43dSSascha Wildner         for (i = 0; i < fastHashFillStep; ++i) {
37a28cd43dSSascha Wildner             size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls);
38a28cd43dSSascha Wildner             size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8);
39a28cd43dSSascha Wildner             if (i == 0)
40a28cd43dSSascha Wildner                 hashSmall[smHash] = curr + i;
41a28cd43dSSascha Wildner             if (i == 0 || hashLarge[lgHash] == 0)
42a28cd43dSSascha Wildner                 hashLarge[lgHash] = curr + i;
43a28cd43dSSascha Wildner             /* Only load extra positions for ZSTD_dtlm_full */
44a28cd43dSSascha Wildner             if (dtlm == ZSTD_dtlm_fast)
45a28cd43dSSascha Wildner                 break;
46a28cd43dSSascha Wildner     }   }
47a28cd43dSSascha Wildner }
48a28cd43dSSascha Wildner 
49a28cd43dSSascha Wildner 
50a28cd43dSSascha Wildner FORCE_INLINE_TEMPLATE
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,ZSTD_dictMode_e const dictMode)51a28cd43dSSascha Wildner size_t ZSTD_compressBlock_doubleFast_generic(
52a28cd43dSSascha Wildner         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
53a28cd43dSSascha Wildner         void const* src, size_t srcSize,
54a28cd43dSSascha Wildner         U32 const mls /* template */, ZSTD_dictMode_e const dictMode)
55a28cd43dSSascha Wildner {
56a28cd43dSSascha Wildner     ZSTD_compressionParameters const* cParams = &ms->cParams;
57a28cd43dSSascha Wildner     U32* const hashLong = ms->hashTable;
58a28cd43dSSascha Wildner     const U32 hBitsL = cParams->hashLog;
59a28cd43dSSascha Wildner     U32* const hashSmall = ms->chainTable;
60a28cd43dSSascha Wildner     const U32 hBitsS = cParams->chainLog;
61a28cd43dSSascha Wildner     const BYTE* const base = ms->window.base;
62a28cd43dSSascha Wildner     const BYTE* const istart = (const BYTE*)src;
63a28cd43dSSascha Wildner     const BYTE* ip = istart;
64a28cd43dSSascha Wildner     const BYTE* anchor = istart;
65a28cd43dSSascha Wildner     const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
66a28cd43dSSascha Wildner     /* presumes that, if there is a dictionary, it must be using Attach mode */
67a28cd43dSSascha Wildner     const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
68a28cd43dSSascha Wildner     const BYTE* const prefixLowest = base + prefixLowestIndex;
69a28cd43dSSascha Wildner     const BYTE* const iend = istart + srcSize;
70a28cd43dSSascha Wildner     const BYTE* const ilimit = iend - HASH_READ_SIZE;
71a28cd43dSSascha Wildner     U32 offset_1=rep[0], offset_2=rep[1];
72a28cd43dSSascha Wildner     U32 offsetSaved = 0;
73a28cd43dSSascha Wildner 
74a28cd43dSSascha Wildner     const ZSTD_matchState_t* const dms = ms->dictMatchState;
75a28cd43dSSascha Wildner     const ZSTD_compressionParameters* const dictCParams =
76a28cd43dSSascha Wildner                                      dictMode == ZSTD_dictMatchState ?
77a28cd43dSSascha Wildner                                      &dms->cParams : NULL;
78a28cd43dSSascha Wildner     const U32* const dictHashLong  = dictMode == ZSTD_dictMatchState ?
79a28cd43dSSascha Wildner                                      dms->hashTable : NULL;
80a28cd43dSSascha Wildner     const U32* const dictHashSmall = dictMode == ZSTD_dictMatchState ?
81a28cd43dSSascha Wildner                                      dms->chainTable : NULL;
82a28cd43dSSascha Wildner     const U32 dictStartIndex       = dictMode == ZSTD_dictMatchState ?
83a28cd43dSSascha Wildner                                      dms->window.dictLimit : 0;
84a28cd43dSSascha Wildner     const BYTE* const dictBase     = dictMode == ZSTD_dictMatchState ?
85a28cd43dSSascha Wildner                                      dms->window.base : NULL;
86a28cd43dSSascha Wildner     const BYTE* const dictStart    = dictMode == ZSTD_dictMatchState ?
87a28cd43dSSascha Wildner                                      dictBase + dictStartIndex : NULL;
88a28cd43dSSascha Wildner     const BYTE* const dictEnd      = dictMode == ZSTD_dictMatchState ?
89a28cd43dSSascha Wildner                                      dms->window.nextSrc : NULL;
90a28cd43dSSascha Wildner     const U32 dictIndexDelta       = dictMode == ZSTD_dictMatchState ?
91a28cd43dSSascha Wildner                                      prefixLowestIndex - (U32)(dictEnd - dictBase) :
92a28cd43dSSascha Wildner                                      0;
93a28cd43dSSascha Wildner     const U32 dictHBitsL           = dictMode == ZSTD_dictMatchState ?
94a28cd43dSSascha Wildner                                      dictCParams->hashLog : hBitsL;
95a28cd43dSSascha Wildner     const U32 dictHBitsS           = dictMode == ZSTD_dictMatchState ?
96a28cd43dSSascha Wildner                                      dictCParams->chainLog : hBitsS;
97a28cd43dSSascha Wildner     const U32 dictAndPrefixLength  = (U32)((ip - prefixLowest) + (dictEnd - dictStart));
98a28cd43dSSascha Wildner 
99a28cd43dSSascha Wildner     DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_generic");
100a28cd43dSSascha Wildner 
101a28cd43dSSascha Wildner     assert(dictMode == ZSTD_noDict || dictMode == ZSTD_dictMatchState);
102a28cd43dSSascha Wildner 
103a28cd43dSSascha Wildner     /* if a dictionary is attached, it must be within window range */
104a28cd43dSSascha Wildner     if (dictMode == ZSTD_dictMatchState) {
105a28cd43dSSascha Wildner         assert(ms->window.dictLimit + (1U << cParams->windowLog) >= endIndex);
106a28cd43dSSascha Wildner     }
107a28cd43dSSascha Wildner 
108a28cd43dSSascha Wildner     /* init */
109a28cd43dSSascha Wildner     ip += (dictAndPrefixLength == 0);
110a28cd43dSSascha Wildner     if (dictMode == ZSTD_noDict) {
111a28cd43dSSascha Wildner         U32 const curr = (U32)(ip - base);
112a28cd43dSSascha Wildner         U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, curr, cParams->windowLog);
113a28cd43dSSascha Wildner         U32 const maxRep = curr - windowLow;
114a28cd43dSSascha Wildner         if (offset_2 > maxRep) offsetSaved = offset_2, offset_2 = 0;
115a28cd43dSSascha Wildner         if (offset_1 > maxRep) offsetSaved = offset_1, offset_1 = 0;
116a28cd43dSSascha Wildner     }
117a28cd43dSSascha Wildner     if (dictMode == ZSTD_dictMatchState) {
118a28cd43dSSascha Wildner         /* dictMatchState repCode checks don't currently handle repCode == 0
119a28cd43dSSascha Wildner          * disabling. */
120a28cd43dSSascha Wildner         assert(offset_1 <= dictAndPrefixLength);
121a28cd43dSSascha Wildner         assert(offset_2 <= dictAndPrefixLength);
122a28cd43dSSascha Wildner     }
123a28cd43dSSascha Wildner 
124a28cd43dSSascha Wildner     /* Main Search Loop */
125a28cd43dSSascha Wildner     while (ip < ilimit) {   /* < instead of <=, because repcode check at (ip+1) */
126a28cd43dSSascha Wildner         size_t mLength;
127a28cd43dSSascha Wildner         U32 offset;
128a28cd43dSSascha Wildner         size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
129a28cd43dSSascha Wildner         size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
130a28cd43dSSascha Wildner         size_t const dictHL = ZSTD_hashPtr(ip, dictHBitsL, 8);
131a28cd43dSSascha Wildner         size_t const dictHS = ZSTD_hashPtr(ip, dictHBitsS, mls);
132a28cd43dSSascha Wildner         U32 const curr = (U32)(ip-base);
133a28cd43dSSascha Wildner         U32 const matchIndexL = hashLong[h2];
134a28cd43dSSascha Wildner         U32 matchIndexS = hashSmall[h];
135a28cd43dSSascha Wildner         const BYTE* matchLong = base + matchIndexL;
136a28cd43dSSascha Wildner         const BYTE* match = base + matchIndexS;
137a28cd43dSSascha Wildner         const U32 repIndex = curr + 1 - offset_1;
138a28cd43dSSascha Wildner         const BYTE* repMatch = (dictMode == ZSTD_dictMatchState
139a28cd43dSSascha Wildner                             && repIndex < prefixLowestIndex) ?
140a28cd43dSSascha Wildner                                dictBase + (repIndex - dictIndexDelta) :
141a28cd43dSSascha Wildner                                base + repIndex;
142a28cd43dSSascha Wildner         hashLong[h2] = hashSmall[h] = curr;   /* update hash tables */
143a28cd43dSSascha Wildner 
144a28cd43dSSascha Wildner         /* check dictMatchState repcode */
145a28cd43dSSascha Wildner         if (dictMode == ZSTD_dictMatchState
146a28cd43dSSascha Wildner             && ((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
147a28cd43dSSascha Wildner             && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
148a28cd43dSSascha Wildner             const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
149a28cd43dSSascha Wildner             mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
150a28cd43dSSascha Wildner             ip++;
151a28cd43dSSascha Wildner             ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
152a28cd43dSSascha Wildner             goto _match_stored;
153a28cd43dSSascha Wildner         }
154a28cd43dSSascha Wildner 
155a28cd43dSSascha Wildner         /* check noDict repcode */
156a28cd43dSSascha Wildner         if ( dictMode == ZSTD_noDict
157a28cd43dSSascha Wildner           && ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1)))) {
158a28cd43dSSascha Wildner             mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
159a28cd43dSSascha Wildner             ip++;
160a28cd43dSSascha Wildner             ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
161a28cd43dSSascha Wildner             goto _match_stored;
162a28cd43dSSascha Wildner         }
163a28cd43dSSascha Wildner 
164a28cd43dSSascha Wildner         if (matchIndexL > prefixLowestIndex) {
165a28cd43dSSascha Wildner             /* check prefix long match */
166a28cd43dSSascha Wildner             if (MEM_read64(matchLong) == MEM_read64(ip)) {
167a28cd43dSSascha Wildner                 mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
168a28cd43dSSascha Wildner                 offset = (U32)(ip-matchLong);
169a28cd43dSSascha Wildner                 while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
170a28cd43dSSascha Wildner                 goto _match_found;
171a28cd43dSSascha Wildner             }
172a28cd43dSSascha Wildner         } else if (dictMode == ZSTD_dictMatchState) {
173a28cd43dSSascha Wildner             /* check dictMatchState long match */
174a28cd43dSSascha Wildner             U32 const dictMatchIndexL = dictHashLong[dictHL];
175a28cd43dSSascha Wildner             const BYTE* dictMatchL = dictBase + dictMatchIndexL;
176a28cd43dSSascha Wildner             assert(dictMatchL < dictEnd);
177a28cd43dSSascha Wildner 
178a28cd43dSSascha Wildner             if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) {
179a28cd43dSSascha Wildner                 mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
180a28cd43dSSascha Wildner                 offset = (U32)(curr - dictMatchIndexL - dictIndexDelta);
181a28cd43dSSascha Wildner                 while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
182a28cd43dSSascha Wildner                 goto _match_found;
183a28cd43dSSascha Wildner         }   }
184a28cd43dSSascha Wildner 
185a28cd43dSSascha Wildner         if (matchIndexS > prefixLowestIndex) {
186a28cd43dSSascha Wildner             /* check prefix short match */
187a28cd43dSSascha Wildner             if (MEM_read32(match) == MEM_read32(ip)) {
188a28cd43dSSascha Wildner                 goto _search_next_long;
189a28cd43dSSascha Wildner             }
190a28cd43dSSascha Wildner         } else if (dictMode == ZSTD_dictMatchState) {
191a28cd43dSSascha Wildner             /* check dictMatchState short match */
192a28cd43dSSascha Wildner             U32 const dictMatchIndexS = dictHashSmall[dictHS];
193a28cd43dSSascha Wildner             match = dictBase + dictMatchIndexS;
194a28cd43dSSascha Wildner             matchIndexS = dictMatchIndexS + dictIndexDelta;
195a28cd43dSSascha Wildner 
196a28cd43dSSascha Wildner             if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) {
197a28cd43dSSascha Wildner                 goto _search_next_long;
198a28cd43dSSascha Wildner         }   }
199a28cd43dSSascha Wildner 
200a28cd43dSSascha Wildner         ip += ((ip-anchor) >> kSearchStrength) + 1;
201a28cd43dSSascha Wildner #if defined(__aarch64__)
202a28cd43dSSascha Wildner         PREFETCH_L1(ip+256);
203a28cd43dSSascha Wildner #endif
204a28cd43dSSascha Wildner         continue;
205a28cd43dSSascha Wildner 
206a28cd43dSSascha Wildner _search_next_long:
207a28cd43dSSascha Wildner 
208a28cd43dSSascha Wildner         {   size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
209a28cd43dSSascha Wildner             size_t const dictHLNext = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
210a28cd43dSSascha Wildner             U32 const matchIndexL3 = hashLong[hl3];
211a28cd43dSSascha Wildner             const BYTE* matchL3 = base + matchIndexL3;
212a28cd43dSSascha Wildner             hashLong[hl3] = curr + 1;
213a28cd43dSSascha Wildner 
214a28cd43dSSascha Wildner             /* check prefix long +1 match */
215a28cd43dSSascha Wildner             if (matchIndexL3 > prefixLowestIndex) {
216a28cd43dSSascha Wildner                 if (MEM_read64(matchL3) == MEM_read64(ip+1)) {
217a28cd43dSSascha Wildner                     mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
218a28cd43dSSascha Wildner                     ip++;
219a28cd43dSSascha Wildner                     offset = (U32)(ip-matchL3);
220a28cd43dSSascha Wildner                     while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
221a28cd43dSSascha Wildner                     goto _match_found;
222a28cd43dSSascha Wildner                 }
223a28cd43dSSascha Wildner             } else if (dictMode == ZSTD_dictMatchState) {
224a28cd43dSSascha Wildner                 /* check dict long +1 match */
225a28cd43dSSascha Wildner                 U32 const dictMatchIndexL3 = dictHashLong[dictHLNext];
226a28cd43dSSascha Wildner                 const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3;
227a28cd43dSSascha Wildner                 assert(dictMatchL3 < dictEnd);
228a28cd43dSSascha Wildner                 if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) {
229a28cd43dSSascha Wildner                     mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8;
230a28cd43dSSascha Wildner                     ip++;
231a28cd43dSSascha Wildner                     offset = (U32)(curr + 1 - dictMatchIndexL3 - dictIndexDelta);
232a28cd43dSSascha Wildner                     while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */
233a28cd43dSSascha Wildner                     goto _match_found;
234a28cd43dSSascha Wildner         }   }   }
235a28cd43dSSascha Wildner 
236a28cd43dSSascha Wildner         /* if no long +1 match, explore the short match we found */
237a28cd43dSSascha Wildner         if (dictMode == ZSTD_dictMatchState && matchIndexS < prefixLowestIndex) {
238a28cd43dSSascha Wildner             mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4;
239a28cd43dSSascha Wildner             offset = (U32)(curr - matchIndexS);
240a28cd43dSSascha Wildner             while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
241a28cd43dSSascha Wildner         } else {
242a28cd43dSSascha Wildner             mLength = ZSTD_count(ip+4, match+4, iend) + 4;
243a28cd43dSSascha Wildner             offset = (U32)(ip - match);
244a28cd43dSSascha Wildner             while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
245a28cd43dSSascha Wildner         }
246a28cd43dSSascha Wildner 
247a28cd43dSSascha Wildner         /* fall-through */
248a28cd43dSSascha Wildner 
249a28cd43dSSascha Wildner _match_found:
250a28cd43dSSascha Wildner         offset_2 = offset_1;
251a28cd43dSSascha Wildner         offset_1 = offset;
252a28cd43dSSascha Wildner 
253a28cd43dSSascha Wildner         ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
254a28cd43dSSascha Wildner 
255a28cd43dSSascha Wildner _match_stored:
256a28cd43dSSascha Wildner         /* match found */
257a28cd43dSSascha Wildner         ip += mLength;
258a28cd43dSSascha Wildner         anchor = ip;
259a28cd43dSSascha Wildner 
260a28cd43dSSascha Wildner         if (ip <= ilimit) {
261a28cd43dSSascha Wildner             /* Complementary insertion */
262a28cd43dSSascha Wildner             /* done after iLimit test, as candidates could be > iend-8 */
263a28cd43dSSascha Wildner             {   U32 const indexToInsert = curr+2;
264a28cd43dSSascha Wildner                 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
265a28cd43dSSascha Wildner                 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
266a28cd43dSSascha Wildner                 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
267a28cd43dSSascha Wildner                 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
268a28cd43dSSascha Wildner             }
269a28cd43dSSascha Wildner 
270a28cd43dSSascha Wildner             /* check immediate repcode */
271a28cd43dSSascha Wildner             if (dictMode == ZSTD_dictMatchState) {
272a28cd43dSSascha Wildner                 while (ip <= ilimit) {
273a28cd43dSSascha Wildner                     U32 const current2 = (U32)(ip-base);
274a28cd43dSSascha Wildner                     U32 const repIndex2 = current2 - offset_2;
275a28cd43dSSascha Wildner                     const BYTE* repMatch2 = dictMode == ZSTD_dictMatchState
276a28cd43dSSascha Wildner                         && repIndex2 < prefixLowestIndex ?
277a28cd43dSSascha Wildner                             dictBase + repIndex2 - dictIndexDelta :
278a28cd43dSSascha Wildner                             base + repIndex2;
279a28cd43dSSascha Wildner                     if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
280a28cd43dSSascha Wildner                        && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
281a28cd43dSSascha Wildner                         const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
282a28cd43dSSascha Wildner                         size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
283a28cd43dSSascha Wildner                         U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
284a28cd43dSSascha Wildner                         ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
285a28cd43dSSascha Wildner                         hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
286a28cd43dSSascha Wildner                         hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
287a28cd43dSSascha Wildner                         ip += repLength2;
288a28cd43dSSascha Wildner                         anchor = ip;
289a28cd43dSSascha Wildner                         continue;
290a28cd43dSSascha Wildner                     }
291a28cd43dSSascha Wildner                     break;
292a28cd43dSSascha Wildner             }   }
293a28cd43dSSascha Wildner 
294a28cd43dSSascha Wildner             if (dictMode == ZSTD_noDict) {
295a28cd43dSSascha Wildner                 while ( (ip <= ilimit)
296a28cd43dSSascha Wildner                      && ( (offset_2>0)
297a28cd43dSSascha Wildner                         & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
298a28cd43dSSascha Wildner                     /* store sequence */
299a28cd43dSSascha Wildner                     size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
300a28cd43dSSascha Wildner                     U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff;  /* swap offset_2 <=> offset_1 */
301a28cd43dSSascha Wildner                     hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
302a28cd43dSSascha Wildner                     hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
303a28cd43dSSascha Wildner                     ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, rLength-MINMATCH);
304a28cd43dSSascha Wildner                     ip += rLength;
305a28cd43dSSascha Wildner                     anchor = ip;
306a28cd43dSSascha Wildner                     continue;   /* faster when present ... (?) */
307a28cd43dSSascha Wildner         }   }   }
308a28cd43dSSascha Wildner     }   /* while (ip < ilimit) */
309a28cd43dSSascha Wildner 
310a28cd43dSSascha Wildner     /* save reps for next block */
311a28cd43dSSascha Wildner     rep[0] = offset_1 ? offset_1 : offsetSaved;
312a28cd43dSSascha Wildner     rep[1] = offset_2 ? offset_2 : offsetSaved;
313a28cd43dSSascha Wildner 
314a28cd43dSSascha Wildner     /* Return the last literals size */
315a28cd43dSSascha Wildner     return (size_t)(iend - anchor);
316a28cd43dSSascha Wildner }
317a28cd43dSSascha Wildner 
318a28cd43dSSascha Wildner 
ZSTD_compressBlock_doubleFast(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize)319a28cd43dSSascha Wildner size_t ZSTD_compressBlock_doubleFast(
320a28cd43dSSascha Wildner         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
321a28cd43dSSascha Wildner         void const* src, size_t srcSize)
322a28cd43dSSascha Wildner {
323a28cd43dSSascha Wildner     const U32 mls = ms->cParams.minMatch;
324a28cd43dSSascha Wildner     switch(mls)
325a28cd43dSSascha Wildner     {
326a28cd43dSSascha Wildner     default: /* includes case 3 */
327a28cd43dSSascha Wildner     case 4 :
328a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_noDict);
329a28cd43dSSascha Wildner     case 5 :
330a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_noDict);
331a28cd43dSSascha Wildner     case 6 :
332a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_noDict);
333a28cd43dSSascha Wildner     case 7 :
334a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_noDict);
335a28cd43dSSascha Wildner     }
336a28cd43dSSascha Wildner }
337a28cd43dSSascha Wildner 
338a28cd43dSSascha Wildner 
ZSTD_compressBlock_doubleFast_dictMatchState(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize)339a28cd43dSSascha Wildner size_t ZSTD_compressBlock_doubleFast_dictMatchState(
340a28cd43dSSascha Wildner         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
341a28cd43dSSascha Wildner         void const* src, size_t srcSize)
342a28cd43dSSascha Wildner {
343a28cd43dSSascha Wildner     const U32 mls = ms->cParams.minMatch;
344a28cd43dSSascha Wildner     switch(mls)
345a28cd43dSSascha Wildner     {
346a28cd43dSSascha Wildner     default: /* includes case 3 */
347a28cd43dSSascha Wildner     case 4 :
348a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 4, ZSTD_dictMatchState);
349a28cd43dSSascha Wildner     case 5 :
350a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 5, ZSTD_dictMatchState);
351a28cd43dSSascha Wildner     case 6 :
352a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 6, ZSTD_dictMatchState);
353a28cd43dSSascha Wildner     case 7 :
354a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, 7, ZSTD_dictMatchState);
355a28cd43dSSascha Wildner     }
356a28cd43dSSascha Wildner }
357a28cd43dSSascha Wildner 
358a28cd43dSSascha Wildner 
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)359a28cd43dSSascha Wildner static size_t ZSTD_compressBlock_doubleFast_extDict_generic(
360a28cd43dSSascha Wildner         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
361a28cd43dSSascha Wildner         void const* src, size_t srcSize,
362a28cd43dSSascha Wildner         U32 const mls /* template */)
363a28cd43dSSascha Wildner {
364a28cd43dSSascha Wildner     ZSTD_compressionParameters const* cParams = &ms->cParams;
365a28cd43dSSascha Wildner     U32* const hashLong = ms->hashTable;
366a28cd43dSSascha Wildner     U32  const hBitsL = cParams->hashLog;
367a28cd43dSSascha Wildner     U32* const hashSmall = ms->chainTable;
368a28cd43dSSascha Wildner     U32  const hBitsS = cParams->chainLog;
369a28cd43dSSascha Wildner     const BYTE* const istart = (const BYTE*)src;
370a28cd43dSSascha Wildner     const BYTE* ip = istart;
371a28cd43dSSascha Wildner     const BYTE* anchor = istart;
372a28cd43dSSascha Wildner     const BYTE* const iend = istart + srcSize;
373a28cd43dSSascha Wildner     const BYTE* const ilimit = iend - 8;
374a28cd43dSSascha Wildner     const BYTE* const base = ms->window.base;
375a28cd43dSSascha Wildner     const U32   endIndex = (U32)((size_t)(istart - base) + srcSize);
376a28cd43dSSascha Wildner     const U32   lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
377a28cd43dSSascha Wildner     const U32   dictStartIndex = lowLimit;
378a28cd43dSSascha Wildner     const U32   dictLimit = ms->window.dictLimit;
379a28cd43dSSascha Wildner     const U32   prefixStartIndex = (dictLimit > lowLimit) ? dictLimit : lowLimit;
380a28cd43dSSascha Wildner     const BYTE* const prefixStart = base + prefixStartIndex;
381a28cd43dSSascha Wildner     const BYTE* const dictBase = ms->window.dictBase;
382a28cd43dSSascha Wildner     const BYTE* const dictStart = dictBase + dictStartIndex;
383a28cd43dSSascha Wildner     const BYTE* const dictEnd = dictBase + prefixStartIndex;
384a28cd43dSSascha Wildner     U32 offset_1=rep[0], offset_2=rep[1];
385a28cd43dSSascha Wildner 
386a28cd43dSSascha Wildner     DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
387a28cd43dSSascha Wildner 
388a28cd43dSSascha Wildner     /* if extDict is invalidated due to maxDistance, switch to "regular" variant */
389a28cd43dSSascha Wildner     if (prefixStartIndex == dictStartIndex)
390a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_generic(ms, seqStore, rep, src, srcSize, mls, ZSTD_noDict);
391a28cd43dSSascha Wildner 
392a28cd43dSSascha Wildner     /* Search Loop */
393a28cd43dSSascha Wildner     while (ip < ilimit) {  /* < instead of <=, because (ip+1) */
394a28cd43dSSascha Wildner         const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
395a28cd43dSSascha Wildner         const U32 matchIndex = hashSmall[hSmall];
396a28cd43dSSascha Wildner         const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
397a28cd43dSSascha Wildner         const BYTE* match = matchBase + matchIndex;
398a28cd43dSSascha Wildner 
399a28cd43dSSascha Wildner         const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
400a28cd43dSSascha Wildner         const U32 matchLongIndex = hashLong[hLong];
401a28cd43dSSascha Wildner         const BYTE* const matchLongBase = matchLongIndex < prefixStartIndex ? dictBase : base;
402a28cd43dSSascha Wildner         const BYTE* matchLong = matchLongBase + matchLongIndex;
403a28cd43dSSascha Wildner 
404a28cd43dSSascha Wildner         const U32 curr = (U32)(ip-base);
405a28cd43dSSascha Wildner         const U32 repIndex = curr + 1 - offset_1;   /* offset_1 expected <= curr +1 */
406a28cd43dSSascha Wildner         const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
407a28cd43dSSascha Wildner         const BYTE* const repMatch = repBase + repIndex;
408a28cd43dSSascha Wildner         size_t mLength;
409a28cd43dSSascha Wildner         hashSmall[hSmall] = hashLong[hLong] = curr;   /* update hash table */
410a28cd43dSSascha Wildner 
411a28cd43dSSascha Wildner         if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
412a28cd43dSSascha Wildner             & (repIndex > dictStartIndex))
413a28cd43dSSascha Wildner           && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
414a28cd43dSSascha Wildner             const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
415a28cd43dSSascha Wildner             mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
416a28cd43dSSascha Wildner             ip++;
417a28cd43dSSascha Wildner             ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, 0, mLength-MINMATCH);
418a28cd43dSSascha Wildner         } else {
419a28cd43dSSascha Wildner             if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
420a28cd43dSSascha Wildner                 const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
421a28cd43dSSascha Wildner                 const BYTE* const lowMatchPtr = matchLongIndex < prefixStartIndex ? dictStart : prefixStart;
422a28cd43dSSascha Wildner                 U32 offset;
423a28cd43dSSascha Wildner                 mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, prefixStart) + 8;
424a28cd43dSSascha Wildner                 offset = curr - matchLongIndex;
425a28cd43dSSascha Wildner                 while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; }   /* catch up */
426a28cd43dSSascha Wildner                 offset_2 = offset_1;
427a28cd43dSSascha Wildner                 offset_1 = offset;
428a28cd43dSSascha Wildner                 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
429a28cd43dSSascha Wildner 
430a28cd43dSSascha Wildner             } else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
431a28cd43dSSascha Wildner                 size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
432a28cd43dSSascha Wildner                 U32 const matchIndex3 = hashLong[h3];
433a28cd43dSSascha Wildner                 const BYTE* const match3Base = matchIndex3 < prefixStartIndex ? dictBase : base;
434a28cd43dSSascha Wildner                 const BYTE* match3 = match3Base + matchIndex3;
435a28cd43dSSascha Wildner                 U32 offset;
436a28cd43dSSascha Wildner                 hashLong[h3] = curr + 1;
437a28cd43dSSascha Wildner                 if ( (matchIndex3 > dictStartIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
438a28cd43dSSascha Wildner                     const BYTE* const matchEnd = matchIndex3 < prefixStartIndex ? dictEnd : iend;
439a28cd43dSSascha Wildner                     const BYTE* const lowMatchPtr = matchIndex3 < prefixStartIndex ? dictStart : prefixStart;
440a28cd43dSSascha Wildner                     mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, prefixStart) + 8;
441a28cd43dSSascha Wildner                     ip++;
442a28cd43dSSascha Wildner                     offset = curr+1 - matchIndex3;
443a28cd43dSSascha Wildner                     while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
444a28cd43dSSascha Wildner                 } else {
445a28cd43dSSascha Wildner                     const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
446a28cd43dSSascha Wildner                     const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
447a28cd43dSSascha Wildner                     mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
448a28cd43dSSascha Wildner                     offset = curr - matchIndex;
449a28cd43dSSascha Wildner                     while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; }   /* catch up */
450a28cd43dSSascha Wildner                 }
451a28cd43dSSascha Wildner                 offset_2 = offset_1;
452a28cd43dSSascha Wildner                 offset_1 = offset;
453a28cd43dSSascha Wildner                 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, offset + ZSTD_REP_MOVE, mLength-MINMATCH);
454a28cd43dSSascha Wildner 
455a28cd43dSSascha Wildner             } else {
456a28cd43dSSascha Wildner                 ip += ((ip-anchor) >> kSearchStrength) + 1;
457a28cd43dSSascha Wildner                 continue;
458a28cd43dSSascha Wildner         }   }
459a28cd43dSSascha Wildner 
460a28cd43dSSascha Wildner         /* move to next sequence start */
461a28cd43dSSascha Wildner         ip += mLength;
462a28cd43dSSascha Wildner         anchor = ip;
463a28cd43dSSascha Wildner 
464a28cd43dSSascha Wildner         if (ip <= ilimit) {
465a28cd43dSSascha Wildner             /* Complementary insertion */
466a28cd43dSSascha Wildner             /* done after iLimit test, as candidates could be > iend-8 */
467a28cd43dSSascha Wildner             {   U32 const indexToInsert = curr+2;
468a28cd43dSSascha Wildner                 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
469a28cd43dSSascha Wildner                 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
470a28cd43dSSascha Wildner                 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
471a28cd43dSSascha Wildner                 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
472a28cd43dSSascha Wildner             }
473a28cd43dSSascha Wildner 
474a28cd43dSSascha Wildner             /* check immediate repcode */
475a28cd43dSSascha Wildner             while (ip <= ilimit) {
476a28cd43dSSascha Wildner                 U32 const current2 = (U32)(ip-base);
477a28cd43dSSascha Wildner                 U32 const repIndex2 = current2 - offset_2;
478a28cd43dSSascha Wildner                 const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
479a28cd43dSSascha Wildner                 if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3)   /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
480a28cd43dSSascha Wildner                     & (repIndex2 > dictStartIndex))
481a28cd43dSSascha Wildner                   && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
482a28cd43dSSascha Wildner                     const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
483a28cd43dSSascha Wildner                     size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
484a28cd43dSSascha Wildner                     U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset;   /* swap offset_2 <=> offset_1 */
485a28cd43dSSascha Wildner                     ZSTD_storeSeq(seqStore, 0, anchor, iend, 0, repLength2-MINMATCH);
486a28cd43dSSascha Wildner                     hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
487a28cd43dSSascha Wildner                     hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
488a28cd43dSSascha Wildner                     ip += repLength2;
489a28cd43dSSascha Wildner                     anchor = ip;
490a28cd43dSSascha Wildner                     continue;
491a28cd43dSSascha Wildner                 }
492a28cd43dSSascha Wildner                 break;
493a28cd43dSSascha Wildner     }   }   }
494a28cd43dSSascha Wildner 
495a28cd43dSSascha Wildner     /* save reps for next block */
496a28cd43dSSascha Wildner     rep[0] = offset_1;
497a28cd43dSSascha Wildner     rep[1] = offset_2;
498a28cd43dSSascha Wildner 
499a28cd43dSSascha Wildner     /* Return the last literals size */
500a28cd43dSSascha Wildner     return (size_t)(iend - anchor);
501a28cd43dSSascha Wildner }
502a28cd43dSSascha Wildner 
503a28cd43dSSascha Wildner 
ZSTD_compressBlock_doubleFast_extDict(ZSTD_matchState_t * ms,seqStore_t * seqStore,U32 rep[ZSTD_REP_NUM],void const * src,size_t srcSize)504a28cd43dSSascha Wildner size_t ZSTD_compressBlock_doubleFast_extDict(
505a28cd43dSSascha Wildner         ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
506a28cd43dSSascha Wildner         void const* src, size_t srcSize)
507a28cd43dSSascha Wildner {
508a28cd43dSSascha Wildner     U32 const mls = ms->cParams.minMatch;
509a28cd43dSSascha Wildner     switch(mls)
510a28cd43dSSascha Wildner     {
511a28cd43dSSascha Wildner     default: /* includes case 3 */
512a28cd43dSSascha Wildner     case 4 :
513a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 4);
514a28cd43dSSascha Wildner     case 5 :
515a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 5);
516a28cd43dSSascha Wildner     case 6 :
517a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 6);
518a28cd43dSSascha Wildner     case 7 :
519a28cd43dSSascha Wildner         return ZSTD_compressBlock_doubleFast_extDict_generic(ms, seqStore, rep, src, srcSize, 7);
520a28cd43dSSascha Wildner     }
521a28cd43dSSascha Wildner }
522