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zstd_double_fast.c
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1/*
2 * Copyright (c) Meta Platforms, Inc. and affiliates.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
12#include "zstd_double_fast.h"
13
14#ifndef ZSTD_EXCLUDE_DFAST_BLOCK_COMPRESSOR
15
16static
18void ZSTD_fillDoubleHashTableForCDict(ZSTD_matchState_t* ms,
19 void const* end, ZSTD_dictTableLoadMethod_e dtlm)
20{
21 const ZSTD_compressionParameters* const cParams = &ms->cParams;
22 U32* const hashLarge = ms->hashTable;
23 U32 const hBitsL = cParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS;
24 U32 const mls = cParams->minMatch;
25 U32* const hashSmall = ms->chainTable;
26 U32 const hBitsS = cParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS;
27 const BYTE* const base = ms->window.base;
28 const BYTE* ip = base + ms->nextToUpdate;
29 const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
30 const U32 fastHashFillStep = 3;
31
32 /* Always insert every fastHashFillStep position into the hash tables.
33 * Insert the other positions into the large hash table if their entry
34 * is empty.
35 */
36 for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
37 U32 const curr = (U32)(ip - base);
38 U32 i;
39 for (i = 0; i < fastHashFillStep; ++i) {
40 size_t const smHashAndTag = ZSTD_hashPtr(ip + i, hBitsS, mls);
41 size_t const lgHashAndTag = ZSTD_hashPtr(ip + i, hBitsL, 8);
42 if (i == 0) {
43 ZSTD_writeTaggedIndex(hashSmall, smHashAndTag, curr + i);
44 }
45 if (i == 0 || hashLarge[lgHashAndTag >> ZSTD_SHORT_CACHE_TAG_BITS] == 0) {
46 ZSTD_writeTaggedIndex(hashLarge, lgHashAndTag, curr + i);
47 }
48 /* Only load extra positions for ZSTD_dtlm_full */
49 if (dtlm == ZSTD_dtlm_fast)
50 break;
51 } }
52}
53
54static
56void ZSTD_fillDoubleHashTableForCCtx(ZSTD_matchState_t* ms,
57 void const* end, ZSTD_dictTableLoadMethod_e dtlm)
58{
59 const ZSTD_compressionParameters* const cParams = &ms->cParams;
60 U32* const hashLarge = ms->hashTable;
61 U32 const hBitsL = cParams->hashLog;
62 U32 const mls = cParams->minMatch;
63 U32* const hashSmall = ms->chainTable;
64 U32 const hBitsS = cParams->chainLog;
65 const BYTE* const base = ms->window.base;
66 const BYTE* ip = base + ms->nextToUpdate;
67 const BYTE* const iend = ((const BYTE*)end) - HASH_READ_SIZE;
68 const U32 fastHashFillStep = 3;
69
70 /* Always insert every fastHashFillStep position into the hash tables.
71 * Insert the other positions into the large hash table if their entry
72 * is empty.
73 */
74 for (; ip + fastHashFillStep - 1 <= iend; ip += fastHashFillStep) {
75 U32 const curr = (U32)(ip - base);
76 U32 i;
77 for (i = 0; i < fastHashFillStep; ++i) {
78 size_t const smHash = ZSTD_hashPtr(ip + i, hBitsS, mls);
79 size_t const lgHash = ZSTD_hashPtr(ip + i, hBitsL, 8);
80 if (i == 0)
81 hashSmall[smHash] = curr + i;
82 if (i == 0 || hashLarge[lgHash] == 0)
83 hashLarge[lgHash] = curr + i;
84 /* Only load extra positions for ZSTD_dtlm_full */
85 if (dtlm == ZSTD_dtlm_fast)
86 break;
87 } }
88}
89
91 const void* const end,
94{
95 if (tfp == ZSTD_tfp_forCDict) {
96 ZSTD_fillDoubleHashTableForCDict(ms, end, dtlm);
97 } else {
98 ZSTD_fillDoubleHashTableForCCtx(ms, end, dtlm);
99 }
100}
101
102
106 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
107 void const* src, size_t srcSize, U32 const mls /* template */)
108{
109 ZSTD_compressionParameters const* cParams = &ms->cParams;
110 U32* const hashLong = ms->hashTable;
111 const U32 hBitsL = cParams->hashLog;
112 U32* const hashSmall = ms->chainTable;
113 const U32 hBitsS = cParams->chainLog;
114 const BYTE* const base = ms->window.base;
115 const BYTE* const istart = (const BYTE*)src;
116 const BYTE* anchor = istart;
117 const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
118 /* presumes that, if there is a dictionary, it must be using Attach mode */
119 const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
120 const BYTE* const prefixLowest = base + prefixLowestIndex;
121 const BYTE* const iend = istart + srcSize;
122 const BYTE* const ilimit = iend - HASH_READ_SIZE;
123 U32 offset_1=rep[0], offset_2=rep[1];
124 U32 offsetSaved1 = 0, offsetSaved2 = 0;
125
126 size_t mLength;
127 U32 offset;
128 U32 curr;
129
130 /* how many positions to search before increasing step size */
131 const size_t kStepIncr = 1 << kSearchStrength;
132 /* the position at which to increment the step size if no match is found */
133 const BYTE* nextStep;
134 size_t step; /* the current step size */
135
136 size_t hl0; /* the long hash at ip */
137 size_t hl1; /* the long hash at ip1 */
138
139 U32 idxl0; /* the long match index for ip */
140 U32 idxl1; /* the long match index for ip1 */
141
142 const BYTE* matchl0; /* the long match for ip */
143 const BYTE* matchs0; /* the short match for ip */
144 const BYTE* matchl1; /* the long match for ip1 */
145
146 const BYTE* ip = istart; /* the current position */
147 const BYTE* ip1; /* the next position */
148
149 DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_noDict_generic");
150
151 /* init */
152 ip += ((ip - prefixLowest) == 0);
153 {
154 U32 const current = (U32)(ip - base);
155 U32 const windowLow = ZSTD_getLowestPrefixIndex(ms, current, cParams->windowLog);
156 U32 const maxRep = current - windowLow;
157 if (offset_2 > maxRep) offsetSaved2 = offset_2, offset_2 = 0;
158 if (offset_1 > maxRep) offsetSaved1 = offset_1, offset_1 = 0;
159 }
160
161 /* Outer Loop: one iteration per match found and stored */
162 while (1) {
163 step = 1;
164 nextStep = ip + kStepIncr;
165 ip1 = ip + step;
166
167 if (ip1 > ilimit) {
168 goto _cleanup;
169 }
170
171 hl0 = ZSTD_hashPtr(ip, hBitsL, 8);
172 idxl0 = hashLong[hl0];
173 matchl0 = base + idxl0;
174
175 /* Inner Loop: one iteration per search / position */
176 do {
177 const size_t hs0 = ZSTD_hashPtr(ip, hBitsS, mls);
178 const U32 idxs0 = hashSmall[hs0];
179 curr = (U32)(ip-base);
180 matchs0 = base + idxs0;
181
182 hashLong[hl0] = hashSmall[hs0] = curr; /* update hash tables */
183
184 /* check noDict repcode */
185 if ((offset_1 > 0) & (MEM_read32(ip+1-offset_1) == MEM_read32(ip+1))) {
186 mLength = ZSTD_count(ip+1+4, ip+1+4-offset_1, iend) + 4;
187 ip++;
188 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
189 goto _match_stored;
190 }
191
192 hl1 = ZSTD_hashPtr(ip1, hBitsL, 8);
193
194 if (idxl0 > prefixLowestIndex) {
195 /* check prefix long match */
196 if (MEM_read64(matchl0) == MEM_read64(ip)) {
197 mLength = ZSTD_count(ip+8, matchl0+8, iend) + 8;
198 offset = (U32)(ip-matchl0);
199 while (((ip>anchor) & (matchl0>prefixLowest)) && (ip[-1] == matchl0[-1])) { ip--; matchl0--; mLength++; } /* catch up */
200 goto _match_found;
201 }
202 }
203
204 idxl1 = hashLong[hl1];
205 matchl1 = base + idxl1;
206
207 if (idxs0 > prefixLowestIndex) {
208 /* check prefix short match */
209 if (MEM_read32(matchs0) == MEM_read32(ip)) {
210 goto _search_next_long;
211 }
212 }
213
214 if (ip1 >= nextStep) {
215 PREFETCH_L1(ip1 + 64);
216 PREFETCH_L1(ip1 + 128);
217 step++;
218 nextStep += kStepIncr;
219 }
220 ip = ip1;
221 ip1 += step;
222
223 hl0 = hl1;
224 idxl0 = idxl1;
225 matchl0 = matchl1;
226 #if defined(__aarch64__)
227 PREFETCH_L1(ip+256);
228 #endif
229 } while (ip1 <= ilimit);
230
231_cleanup:
232 /* If offset_1 started invalid (offsetSaved1 != 0) and became valid (offset_1 != 0),
233 * rotate saved offsets. See comment in ZSTD_compressBlock_fast_noDict for more context. */
234 offsetSaved2 = ((offsetSaved1 != 0) && (offset_1 != 0)) ? offsetSaved1 : offsetSaved2;
235
236 /* save reps for next block */
237 rep[0] = offset_1 ? offset_1 : offsetSaved1;
238 rep[1] = offset_2 ? offset_2 : offsetSaved2;
239
240 /* Return the last literals size */
241 return (size_t)(iend - anchor);
242
243_search_next_long:
244
245 /* check prefix long +1 match */
246 if (idxl1 > prefixLowestIndex) {
247 if (MEM_read64(matchl1) == MEM_read64(ip1)) {
248 ip = ip1;
249 mLength = ZSTD_count(ip+8, matchl1+8, iend) + 8;
250 offset = (U32)(ip-matchl1);
251 while (((ip>anchor) & (matchl1>prefixLowest)) && (ip[-1] == matchl1[-1])) { ip--; matchl1--; mLength++; } /* catch up */
252 goto _match_found;
253 }
254 }
255
256 /* if no long +1 match, explore the short match we found */
257 mLength = ZSTD_count(ip+4, matchs0+4, iend) + 4;
258 offset = (U32)(ip - matchs0);
259 while (((ip>anchor) & (matchs0>prefixLowest)) && (ip[-1] == matchs0[-1])) { ip--; matchs0--; mLength++; } /* catch up */
260
261 /* fall-through */
262
263_match_found: /* requires ip, offset, mLength */
264 offset_2 = offset_1;
265 offset_1 = offset;
266
267 if (step < 4) {
268 /* It is unsafe to write this value back to the hashtable when ip1 is
269 * greater than or equal to the new ip we will have after we're done
270 * processing this match. Rather than perform that test directly
271 * (ip1 >= ip + mLength), which costs speed in practice, we do a simpler
272 * more predictable test. The minmatch even if we take a short match is
273 * 4 bytes, so as long as step, the distance between ip and ip1
274 * (initially) is less than 4, we know ip1 < new ip. */
275 hashLong[hl1] = (U32)(ip1 - base);
276 }
277
278 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
279
280_match_stored:
281 /* match found */
282 ip += mLength;
283 anchor = ip;
284
285 if (ip <= ilimit) {
286 /* Complementary insertion */
287 /* done after iLimit test, as candidates could be > iend-8 */
288 { U32 const indexToInsert = curr+2;
289 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
290 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
291 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
292 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
293 }
294
295 /* check immediate repcode */
296 while ( (ip <= ilimit)
297 && ( (offset_2>0)
298 & (MEM_read32(ip) == MEM_read32(ip - offset_2)) )) {
299 /* store sequence */
300 size_t const rLength = ZSTD_count(ip+4, ip+4-offset_2, iend) + 4;
301 U32 const tmpOff = offset_2; offset_2 = offset_1; offset_1 = tmpOff; /* swap offset_2 <=> offset_1 */
302 hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = (U32)(ip-base);
303 hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = (U32)(ip-base);
304 ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, rLength);
305 ip += rLength;
306 anchor = ip;
307 continue; /* faster when present ... (?) */
308 }
309 }
310 }
311}
312
313
317 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
318 void const* src, size_t srcSize,
319 U32 const mls /* template */)
320{
321 ZSTD_compressionParameters const* cParams = &ms->cParams;
322 U32* const hashLong = ms->hashTable;
323 const U32 hBitsL = cParams->hashLog;
324 U32* const hashSmall = ms->chainTable;
325 const U32 hBitsS = cParams->chainLog;
326 const BYTE* const base = ms->window.base;
327 const BYTE* const istart = (const BYTE*)src;
328 const BYTE* ip = istart;
329 const BYTE* anchor = istart;
330 const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
331 /* presumes that, if there is a dictionary, it must be using Attach mode */
332 const U32 prefixLowestIndex = ZSTD_getLowestPrefixIndex(ms, endIndex, cParams->windowLog);
333 const BYTE* const prefixLowest = base + prefixLowestIndex;
334 const BYTE* const iend = istart + srcSize;
335 const BYTE* const ilimit = iend - HASH_READ_SIZE;
336 U32 offset_1=rep[0], offset_2=rep[1];
337
338 const ZSTD_matchState_t* const dms = ms->dictMatchState;
339 const ZSTD_compressionParameters* const dictCParams = &dms->cParams;
340 const U32* const dictHashLong = dms->hashTable;
341 const U32* const dictHashSmall = dms->chainTable;
342 const U32 dictStartIndex = dms->window.dictLimit;
343 const BYTE* const dictBase = dms->window.base;
344 const BYTE* const dictStart = dictBase + dictStartIndex;
345 const BYTE* const dictEnd = dms->window.nextSrc;
346 const U32 dictIndexDelta = prefixLowestIndex - (U32)(dictEnd - dictBase);
347 const U32 dictHBitsL = dictCParams->hashLog + ZSTD_SHORT_CACHE_TAG_BITS;
348 const U32 dictHBitsS = dictCParams->chainLog + ZSTD_SHORT_CACHE_TAG_BITS;
349 const U32 dictAndPrefixLength = (U32)((ip - prefixLowest) + (dictEnd - dictStart));
350
351 DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_dictMatchState_generic");
352
353 /* if a dictionary is attached, it must be within window range */
354 assert(ms->window.dictLimit + (1U << cParams->windowLog) >= endIndex);
355
356 if (ms->prefetchCDictTables) {
357 size_t const hashTableBytes = (((size_t)1) << dictCParams->hashLog) * sizeof(U32);
358 size_t const chainTableBytes = (((size_t)1) << dictCParams->chainLog) * sizeof(U32);
359 PREFETCH_AREA(dictHashLong, hashTableBytes);
360 PREFETCH_AREA(dictHashSmall, chainTableBytes);
361 }
362
363 /* init */
364 ip += (dictAndPrefixLength == 0);
365
366 /* dictMatchState repCode checks don't currently handle repCode == 0
367 * disabling. */
368 assert(offset_1 <= dictAndPrefixLength);
369 assert(offset_2 <= dictAndPrefixLength);
370
371 /* Main Search Loop */
372 while (ip < ilimit) { /* < instead of <=, because repcode check at (ip+1) */
373 size_t mLength;
374 U32 offset;
375 size_t const h2 = ZSTD_hashPtr(ip, hBitsL, 8);
376 size_t const h = ZSTD_hashPtr(ip, hBitsS, mls);
377 size_t const dictHashAndTagL = ZSTD_hashPtr(ip, dictHBitsL, 8);
378 size_t const dictHashAndTagS = ZSTD_hashPtr(ip, dictHBitsS, mls);
379 U32 const dictMatchIndexAndTagL = dictHashLong[dictHashAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS];
380 U32 const dictMatchIndexAndTagS = dictHashSmall[dictHashAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS];
381 int const dictTagsMatchL = ZSTD_comparePackedTags(dictMatchIndexAndTagL, dictHashAndTagL);
382 int const dictTagsMatchS = ZSTD_comparePackedTags(dictMatchIndexAndTagS, dictHashAndTagS);
383 U32 const curr = (U32)(ip-base);
384 U32 const matchIndexL = hashLong[h2];
385 U32 matchIndexS = hashSmall[h];
386 const BYTE* matchLong = base + matchIndexL;
387 const BYTE* match = base + matchIndexS;
388 const U32 repIndex = curr + 1 - offset_1;
389 const BYTE* repMatch = (repIndex < prefixLowestIndex) ?
390 dictBase + (repIndex - dictIndexDelta) :
391 base + repIndex;
392 hashLong[h2] = hashSmall[h] = curr; /* update hash tables */
393
394 /* check repcode */
395 if (((U32)((prefixLowestIndex-1) - repIndex) >= 3 /* intentional underflow */)
396 && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
397 const BYTE* repMatchEnd = repIndex < prefixLowestIndex ? dictEnd : iend;
398 mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixLowest) + 4;
399 ip++;
400 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
401 goto _match_stored;
402 }
403
404 if (matchIndexL > prefixLowestIndex) {
405 /* check prefix long match */
406 if (MEM_read64(matchLong) == MEM_read64(ip)) {
407 mLength = ZSTD_count(ip+8, matchLong+8, iend) + 8;
408 offset = (U32)(ip-matchLong);
409 while (((ip>anchor) & (matchLong>prefixLowest)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
410 goto _match_found;
411 }
412 } else if (dictTagsMatchL) {
413 /* check dictMatchState long match */
414 U32 const dictMatchIndexL = dictMatchIndexAndTagL >> ZSTD_SHORT_CACHE_TAG_BITS;
415 const BYTE* dictMatchL = dictBase + dictMatchIndexL;
416 assert(dictMatchL < dictEnd);
417
418 if (dictMatchL > dictStart && MEM_read64(dictMatchL) == MEM_read64(ip)) {
419 mLength = ZSTD_count_2segments(ip+8, dictMatchL+8, iend, dictEnd, prefixLowest) + 8;
420 offset = (U32)(curr - dictMatchIndexL - dictIndexDelta);
421 while (((ip>anchor) & (dictMatchL>dictStart)) && (ip[-1] == dictMatchL[-1])) { ip--; dictMatchL--; mLength++; } /* catch up */
422 goto _match_found;
423 } }
424
425 if (matchIndexS > prefixLowestIndex) {
426 /* check prefix short match */
427 if (MEM_read32(match) == MEM_read32(ip)) {
428 goto _search_next_long;
429 }
430 } else if (dictTagsMatchS) {
431 /* check dictMatchState short match */
432 U32 const dictMatchIndexS = dictMatchIndexAndTagS >> ZSTD_SHORT_CACHE_TAG_BITS;
433 match = dictBase + dictMatchIndexS;
434 matchIndexS = dictMatchIndexS + dictIndexDelta;
435
436 if (match > dictStart && MEM_read32(match) == MEM_read32(ip)) {
437 goto _search_next_long;
438 } }
439
440 ip += ((ip-anchor) >> kSearchStrength) + 1;
441#if defined(__aarch64__)
442 PREFETCH_L1(ip+256);
443#endif
444 continue;
445
446_search_next_long:
447 { size_t const hl3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
448 size_t const dictHashAndTagL3 = ZSTD_hashPtr(ip+1, dictHBitsL, 8);
449 U32 const matchIndexL3 = hashLong[hl3];
450 U32 const dictMatchIndexAndTagL3 = dictHashLong[dictHashAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS];
451 int const dictTagsMatchL3 = ZSTD_comparePackedTags(dictMatchIndexAndTagL3, dictHashAndTagL3);
452 const BYTE* matchL3 = base + matchIndexL3;
453 hashLong[hl3] = curr + 1;
454
455 /* check prefix long +1 match */
456 if (matchIndexL3 > prefixLowestIndex) {
457 if (MEM_read64(matchL3) == MEM_read64(ip+1)) {
458 mLength = ZSTD_count(ip+9, matchL3+8, iend) + 8;
459 ip++;
460 offset = (U32)(ip-matchL3);
461 while (((ip>anchor) & (matchL3>prefixLowest)) && (ip[-1] == matchL3[-1])) { ip--; matchL3--; mLength++; } /* catch up */
462 goto _match_found;
463 }
464 } else if (dictTagsMatchL3) {
465 /* check dict long +1 match */
466 U32 const dictMatchIndexL3 = dictMatchIndexAndTagL3 >> ZSTD_SHORT_CACHE_TAG_BITS;
467 const BYTE* dictMatchL3 = dictBase + dictMatchIndexL3;
468 assert(dictMatchL3 < dictEnd);
469 if (dictMatchL3 > dictStart && MEM_read64(dictMatchL3) == MEM_read64(ip+1)) {
470 mLength = ZSTD_count_2segments(ip+1+8, dictMatchL3+8, iend, dictEnd, prefixLowest) + 8;
471 ip++;
472 offset = (U32)(curr + 1 - dictMatchIndexL3 - dictIndexDelta);
473 while (((ip>anchor) & (dictMatchL3>dictStart)) && (ip[-1] == dictMatchL3[-1])) { ip--; dictMatchL3--; mLength++; } /* catch up */
474 goto _match_found;
475 } } }
476
477 /* if no long +1 match, explore the short match we found */
478 if (matchIndexS < prefixLowestIndex) {
479 mLength = ZSTD_count_2segments(ip+4, match+4, iend, dictEnd, prefixLowest) + 4;
480 offset = (U32)(curr - matchIndexS);
481 while (((ip>anchor) & (match>dictStart)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
482 } else {
483 mLength = ZSTD_count(ip+4, match+4, iend) + 4;
484 offset = (U32)(ip - match);
485 while (((ip>anchor) & (match>prefixLowest)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
486 }
487
488_match_found:
489 offset_2 = offset_1;
490 offset_1 = offset;
491
492 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
493
494_match_stored:
495 /* match found */
496 ip += mLength;
497 anchor = ip;
498
499 if (ip <= ilimit) {
500 /* Complementary insertion */
501 /* done after iLimit test, as candidates could be > iend-8 */
502 { U32 const indexToInsert = curr+2;
503 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
504 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
505 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
506 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
507 }
508
509 /* check immediate repcode */
510 while (ip <= ilimit) {
511 U32 const current2 = (U32)(ip-base);
512 U32 const repIndex2 = current2 - offset_2;
513 const BYTE* repMatch2 = repIndex2 < prefixLowestIndex ?
514 dictBase + repIndex2 - dictIndexDelta :
515 base + repIndex2;
516 if ( ((U32)((prefixLowestIndex-1) - (U32)repIndex2) >= 3 /* intentional overflow */)
517 && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
518 const BYTE* const repEnd2 = repIndex2 < prefixLowestIndex ? dictEnd : iend;
519 size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixLowest) + 4;
520 U32 tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
521 ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, repLength2);
522 hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
523 hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
524 ip += repLength2;
525 anchor = ip;
526 continue;
527 }
528 break;
529 }
530 }
531 } /* while (ip < ilimit) */
532
533 /* save reps for next block */
534 rep[0] = offset_1;
535 rep[1] = offset_2;
536
537 /* Return the last literals size */
538 return (size_t)(iend - anchor);
539}
540
541#define ZSTD_GEN_DFAST_FN(dictMode, mls) \
542 static size_t ZSTD_compressBlock_doubleFast_##dictMode##_##mls( \
543 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM], \
544 void const* src, size_t srcSize) \
545 { \
546 return ZSTD_compressBlock_doubleFast_##dictMode##_generic(ms, seqStore, rep, src, srcSize, mls); \
547 }
548
549ZSTD_GEN_DFAST_FN(noDict, 4)
550ZSTD_GEN_DFAST_FN(noDict, 5)
551ZSTD_GEN_DFAST_FN(noDict, 6)
552ZSTD_GEN_DFAST_FN(noDict, 7)
553
554ZSTD_GEN_DFAST_FN(dictMatchState, 4)
555ZSTD_GEN_DFAST_FN(dictMatchState, 5)
556ZSTD_GEN_DFAST_FN(dictMatchState, 6)
557ZSTD_GEN_DFAST_FN(dictMatchState, 7)
558
559
561 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
562 void const* src, size_t srcSize)
563{
564 const U32 mls = ms->cParams.minMatch;
565 switch(mls)
566 {
567 default: /* includes case 3 */
568 case 4 :
569 return ZSTD_compressBlock_doubleFast_noDict_4(ms, seqStore, rep, src, srcSize);
570 case 5 :
571 return ZSTD_compressBlock_doubleFast_noDict_5(ms, seqStore, rep, src, srcSize);
572 case 6 :
573 return ZSTD_compressBlock_doubleFast_noDict_6(ms, seqStore, rep, src, srcSize);
574 case 7 :
575 return ZSTD_compressBlock_doubleFast_noDict_7(ms, seqStore, rep, src, srcSize);
576 }
577}
578
579
581 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
582 void const* src, size_t srcSize)
583{
584 const U32 mls = ms->cParams.minMatch;
585 switch(mls)
586 {
587 default: /* includes case 3 */
588 case 4 :
589 return ZSTD_compressBlock_doubleFast_dictMatchState_4(ms, seqStore, rep, src, srcSize);
590 case 5 :
591 return ZSTD_compressBlock_doubleFast_dictMatchState_5(ms, seqStore, rep, src, srcSize);
592 case 6 :
593 return ZSTD_compressBlock_doubleFast_dictMatchState_6(ms, seqStore, rep, src, srcSize);
594 case 7 :
595 return ZSTD_compressBlock_doubleFast_dictMatchState_7(ms, seqStore, rep, src, srcSize);
596 }
597}
598
599
600static
602size_t ZSTD_compressBlock_doubleFast_extDict_generic(
603 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
604 void const* src, size_t srcSize,
605 U32 const mls /* template */)
606{
607 ZSTD_compressionParameters const* cParams = &ms->cParams;
608 U32* const hashLong = ms->hashTable;
609 U32 const hBitsL = cParams->hashLog;
610 U32* const hashSmall = ms->chainTable;
611 U32 const hBitsS = cParams->chainLog;
612 const BYTE* const istart = (const BYTE*)src;
613 const BYTE* ip = istart;
614 const BYTE* anchor = istart;
615 const BYTE* const iend = istart + srcSize;
616 const BYTE* const ilimit = iend - 8;
617 const BYTE* const base = ms->window.base;
618 const U32 endIndex = (U32)((size_t)(istart - base) + srcSize);
619 const U32 lowLimit = ZSTD_getLowestMatchIndex(ms, endIndex, cParams->windowLog);
620 const U32 dictStartIndex = lowLimit;
621 const U32 dictLimit = ms->window.dictLimit;
622 const U32 prefixStartIndex = (dictLimit > lowLimit) ? dictLimit : lowLimit;
623 const BYTE* const prefixStart = base + prefixStartIndex;
624 const BYTE* const dictBase = ms->window.dictBase;
625 const BYTE* const dictStart = dictBase + dictStartIndex;
626 const BYTE* const dictEnd = dictBase + prefixStartIndex;
627 U32 offset_1=rep[0], offset_2=rep[1];
628
629 DEBUGLOG(5, "ZSTD_compressBlock_doubleFast_extDict_generic (srcSize=%zu)", srcSize);
630
631 /* if extDict is invalidated due to maxDistance, switch to "regular" variant */
632 if (prefixStartIndex == dictStartIndex)
633 return ZSTD_compressBlock_doubleFast(ms, seqStore, rep, src, srcSize);
634
635 /* Search Loop */
636 while (ip < ilimit) { /* < instead of <=, because (ip+1) */
637 const size_t hSmall = ZSTD_hashPtr(ip, hBitsS, mls);
638 const U32 matchIndex = hashSmall[hSmall];
639 const BYTE* const matchBase = matchIndex < prefixStartIndex ? dictBase : base;
640 const BYTE* match = matchBase + matchIndex;
641
642 const size_t hLong = ZSTD_hashPtr(ip, hBitsL, 8);
643 const U32 matchLongIndex = hashLong[hLong];
644 const BYTE* const matchLongBase = matchLongIndex < prefixStartIndex ? dictBase : base;
645 const BYTE* matchLong = matchLongBase + matchLongIndex;
646
647 const U32 curr = (U32)(ip-base);
648 const U32 repIndex = curr + 1 - offset_1; /* offset_1 expected <= curr +1 */
649 const BYTE* const repBase = repIndex < prefixStartIndex ? dictBase : base;
650 const BYTE* const repMatch = repBase + repIndex;
651 size_t mLength;
652 hashSmall[hSmall] = hashLong[hLong] = curr; /* update hash table */
653
654 if ((((U32)((prefixStartIndex-1) - repIndex) >= 3) /* intentional underflow : ensure repIndex doesn't overlap dict + prefix */
655 & (offset_1 <= curr+1 - dictStartIndex)) /* note: we are searching at curr+1 */
656 && (MEM_read32(repMatch) == MEM_read32(ip+1)) ) {
657 const BYTE* repMatchEnd = repIndex < prefixStartIndex ? dictEnd : iend;
658 mLength = ZSTD_count_2segments(ip+1+4, repMatch+4, iend, repMatchEnd, prefixStart) + 4;
659 ip++;
660 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, REPCODE1_TO_OFFBASE, mLength);
661 } else {
662 if ((matchLongIndex > dictStartIndex) && (MEM_read64(matchLong) == MEM_read64(ip))) {
663 const BYTE* const matchEnd = matchLongIndex < prefixStartIndex ? dictEnd : iend;
664 const BYTE* const lowMatchPtr = matchLongIndex < prefixStartIndex ? dictStart : prefixStart;
665 U32 offset;
666 mLength = ZSTD_count_2segments(ip+8, matchLong+8, iend, matchEnd, prefixStart) + 8;
667 offset = curr - matchLongIndex;
668 while (((ip>anchor) & (matchLong>lowMatchPtr)) && (ip[-1] == matchLong[-1])) { ip--; matchLong--; mLength++; } /* catch up */
669 offset_2 = offset_1;
670 offset_1 = offset;
671 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
672
673 } else if ((matchIndex > dictStartIndex) && (MEM_read32(match) == MEM_read32(ip))) {
674 size_t const h3 = ZSTD_hashPtr(ip+1, hBitsL, 8);
675 U32 const matchIndex3 = hashLong[h3];
676 const BYTE* const match3Base = matchIndex3 < prefixStartIndex ? dictBase : base;
677 const BYTE* match3 = match3Base + matchIndex3;
678 U32 offset;
679 hashLong[h3] = curr + 1;
680 if ( (matchIndex3 > dictStartIndex) && (MEM_read64(match3) == MEM_read64(ip+1)) ) {
681 const BYTE* const matchEnd = matchIndex3 < prefixStartIndex ? dictEnd : iend;
682 const BYTE* const lowMatchPtr = matchIndex3 < prefixStartIndex ? dictStart : prefixStart;
683 mLength = ZSTD_count_2segments(ip+9, match3+8, iend, matchEnd, prefixStart) + 8;
684 ip++;
685 offset = curr+1 - matchIndex3;
686 while (((ip>anchor) & (match3>lowMatchPtr)) && (ip[-1] == match3[-1])) { ip--; match3--; mLength++; } /* catch up */
687 } else {
688 const BYTE* const matchEnd = matchIndex < prefixStartIndex ? dictEnd : iend;
689 const BYTE* const lowMatchPtr = matchIndex < prefixStartIndex ? dictStart : prefixStart;
690 mLength = ZSTD_count_2segments(ip+4, match+4, iend, matchEnd, prefixStart) + 4;
691 offset = curr - matchIndex;
692 while (((ip>anchor) & (match>lowMatchPtr)) && (ip[-1] == match[-1])) { ip--; match--; mLength++; } /* catch up */
693 }
694 offset_2 = offset_1;
695 offset_1 = offset;
696 ZSTD_storeSeq(seqStore, (size_t)(ip-anchor), anchor, iend, OFFSET_TO_OFFBASE(offset), mLength);
697
698 } else {
699 ip += ((ip-anchor) >> kSearchStrength) + 1;
700 continue;
701 } }
702
703 /* move to next sequence start */
704 ip += mLength;
705 anchor = ip;
706
707 if (ip <= ilimit) {
708 /* Complementary insertion */
709 /* done after iLimit test, as candidates could be > iend-8 */
710 { U32 const indexToInsert = curr+2;
711 hashLong[ZSTD_hashPtr(base+indexToInsert, hBitsL, 8)] = indexToInsert;
712 hashLong[ZSTD_hashPtr(ip-2, hBitsL, 8)] = (U32)(ip-2-base);
713 hashSmall[ZSTD_hashPtr(base+indexToInsert, hBitsS, mls)] = indexToInsert;
714 hashSmall[ZSTD_hashPtr(ip-1, hBitsS, mls)] = (U32)(ip-1-base);
715 }
716
717 /* check immediate repcode */
718 while (ip <= ilimit) {
719 U32 const current2 = (U32)(ip-base);
720 U32 const repIndex2 = current2 - offset_2;
721 const BYTE* repMatch2 = repIndex2 < prefixStartIndex ? dictBase + repIndex2 : base + repIndex2;
722 if ( (((U32)((prefixStartIndex-1) - repIndex2) >= 3) /* intentional overflow : ensure repIndex2 doesn't overlap dict + prefix */
723 & (offset_2 <= current2 - dictStartIndex))
724 && (MEM_read32(repMatch2) == MEM_read32(ip)) ) {
725 const BYTE* const repEnd2 = repIndex2 < prefixStartIndex ? dictEnd : iend;
726 size_t const repLength2 = ZSTD_count_2segments(ip+4, repMatch2+4, iend, repEnd2, prefixStart) + 4;
727 U32 const tmpOffset = offset_2; offset_2 = offset_1; offset_1 = tmpOffset; /* swap offset_2 <=> offset_1 */
728 ZSTD_storeSeq(seqStore, 0, anchor, iend, REPCODE1_TO_OFFBASE, repLength2);
729 hashSmall[ZSTD_hashPtr(ip, hBitsS, mls)] = current2;
730 hashLong[ZSTD_hashPtr(ip, hBitsL, 8)] = current2;
731 ip += repLength2;
732 anchor = ip;
733 continue;
734 }
735 break;
736 } } }
737
738 /* save reps for next block */
739 rep[0] = offset_1;
740 rep[1] = offset_2;
741
742 /* Return the last literals size */
743 return (size_t)(iend - anchor);
744}
745
746ZSTD_GEN_DFAST_FN(extDict, 4)
747ZSTD_GEN_DFAST_FN(extDict, 5)
748ZSTD_GEN_DFAST_FN(extDict, 6)
749ZSTD_GEN_DFAST_FN(extDict, 7)
750
752 ZSTD_matchState_t* ms, seqStore_t* seqStore, U32 rep[ZSTD_REP_NUM],
753 void const* src, size_t srcSize)
754{
755 U32 const mls = ms->cParams.minMatch;
756 switch(mls)
757 {
758 default: /* includes case 3 */
759 case 4 :
760 return ZSTD_compressBlock_doubleFast_extDict_4(ms, seqStore, rep, src, srcSize);
761 case 5 :
762 return ZSTD_compressBlock_doubleFast_extDict_5(ms, seqStore, rep, src, srcSize);
763 case 6 :
764 return ZSTD_compressBlock_doubleFast_extDict_6(ms, seqStore, rep, src, srcSize);
765 case 7 :
766 return ZSTD_compressBlock_doubleFast_extDict_7(ms, seqStore, rep, src, srcSize);
767 }
768}
769
770#endif /* ZSTD_EXCLUDE_DFAST_BLOCK_COMPRESSOR */
#define PREFETCH_AREA(p, s)
Definition: compiler.h:156
#define PREFETCH_L1(ptr)
Definition: compiler.h:149
#define FORCE_INLINE_TEMPLATE
Definition: compiler.h:68
#define ZSTD_ALLOW_POINTER_OVERFLOW_ATTR
Definition: compiler.h:322
#define DEBUGLOG(l,...)
Definition: debug.h:108
#define assert(condition)
Definition: debug.h:74
MEM_STATIC U32 MEM_read32(const void *memPtr)
Definition: mem.h:202
unsigned char BYTE
Definition: mem.h:58
unsigned int U32
Definition: mem.h:69
MEM_STATIC U64 MEM_read64(const void *memPtr)
Definition: mem.h:207
ZSTD_compressionParameters cParams
const ZSTD_matchState_t * dictMatchState
#define ZSTD_SHORT_CACHE_TAG_BITS
MEM_STATIC size_t ZSTD_count_2segments(const BYTE *ip, const BYTE *match, const BYTE *iEnd, const BYTE *mEnd, const BYTE *iStart)
#define OFFSET_TO_OFFBASE(o)
MEM_STATIC void ZSTD_writeTaggedIndex(U32 *const hashTable, size_t hashAndTag, U32 index)
#define kSearchStrength
MEM_STATIC int ZSTD_comparePackedTags(size_t packedTag1, size_t packedTag2)
MEM_STATIC FORCE_INLINE_ATTR size_t ZSTD_hashPtr(const void *p, U32 hBits, U32 mls)
MEM_STATIC size_t ZSTD_count(const BYTE *pIn, const BYTE *pMatch, const BYTE *const pInLimit)
HINT_INLINE UNUSED_ATTR void ZSTD_storeSeq(seqStore_t *seqStorePtr, size_t litLength, const BYTE *literals, const BYTE *litLimit, U32 offBase, size_t matchLength)
MEM_STATIC U32 ZSTD_getLowestMatchIndex(const ZSTD_matchState_t *ms, U32 curr, unsigned windowLog)
MEM_STATIC U32 ZSTD_getLowestPrefixIndex(const ZSTD_matchState_t *ms, U32 curr, unsigned windowLog)
#define REPCODE1_TO_OFFBASE
ZSTD_dictTableLoadMethod_e
@ ZSTD_dtlm_fast
#define HASH_READ_SIZE
ZSTD_tableFillPurpose_e
@ ZSTD_tfp_forCDict
size_t ZSTD_compressBlock_doubleFast(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
size_t ZSTD_compressBlock_doubleFast_extDict(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
void ZSTD_fillDoubleHashTable(ZSTD_matchState_t *ms, const void *const end, ZSTD_dictTableLoadMethod_e dtlm, ZSTD_tableFillPurpose_e tfp)
FORCE_INLINE_TEMPLATE ZSTD_ALLOW_POINTER_OVERFLOW_ATTR size_t ZSTD_compressBlock_doubleFast_dictMatchState_generic(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize, U32 const mls)
size_t ZSTD_compressBlock_doubleFast_dictMatchState(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize)
FORCE_INLINE_TEMPLATE ZSTD_ALLOW_POINTER_OVERFLOW_ATTR size_t ZSTD_compressBlock_doubleFast_noDict_generic(ZSTD_matchState_t *ms, seqStore_t *seqStore, U32 rep[ZSTD_REP_NUM], void const *src, size_t srcSize, U32 const mls)
#define ZSTD_GEN_DFAST_FN(dictMode, mls)
#define ZSTD_REP_NUM
Definition: zstd_internal.h:68