lib: add Zstandard decompression support
[oweals/u-boot.git] / lib / zstd / zstd_opt.h
diff --git a/lib/zstd/zstd_opt.h b/lib/zstd/zstd_opt.h
new file mode 100644 (file)
index 0000000..af0aaf5
--- /dev/null
@@ -0,0 +1,1004 @@
+/* SPDX-License-Identifier: (GPL-2.0 or BSD-3-Clause-Clear) */
+/**
+ * Copyright (c) 2016-present, Przemyslaw Skibinski, Yann Collet, Facebook, Inc.
+ * All rights reserved.
+ */
+
+/* Note : this file is intended to be included within zstd_compress.c */
+
+#ifndef ZSTD_OPT_H_91842398743
+#define ZSTD_OPT_H_91842398743
+
+#define ZSTD_LITFREQ_ADD 2
+#define ZSTD_FREQ_DIV 4
+#define ZSTD_MAX_PRICE (1 << 30)
+
+/*-*************************************
+*  Price functions for optimal parser
+***************************************/
+FORCE_INLINE void ZSTD_setLog2Prices(seqStore_t *ssPtr)
+{
+       ssPtr->log2matchLengthSum = ZSTD_highbit32(ssPtr->matchLengthSum + 1);
+       ssPtr->log2litLengthSum = ZSTD_highbit32(ssPtr->litLengthSum + 1);
+       ssPtr->log2litSum = ZSTD_highbit32(ssPtr->litSum + 1);
+       ssPtr->log2offCodeSum = ZSTD_highbit32(ssPtr->offCodeSum + 1);
+       ssPtr->factor = 1 + ((ssPtr->litSum >> 5) / ssPtr->litLengthSum) + ((ssPtr->litSum << 1) / (ssPtr->litSum + ssPtr->matchSum));
+}
+
+ZSTD_STATIC void ZSTD_rescaleFreqs(seqStore_t *ssPtr, const BYTE *src, size_t srcSize)
+{
+       unsigned u;
+
+       ssPtr->cachedLiterals = NULL;
+       ssPtr->cachedPrice = ssPtr->cachedLitLength = 0;
+       ssPtr->staticPrices = 0;
+
+       if (ssPtr->litLengthSum == 0) {
+               if (srcSize <= 1024)
+                       ssPtr->staticPrices = 1;
+
+               for (u = 0; u <= MaxLit; u++)
+                       ssPtr->litFreq[u] = 0;
+               for (u = 0; u < srcSize; u++)
+                       ssPtr->litFreq[src[u]]++;
+
+               ssPtr->litSum = 0;
+               ssPtr->litLengthSum = MaxLL + 1;
+               ssPtr->matchLengthSum = MaxML + 1;
+               ssPtr->offCodeSum = (MaxOff + 1);
+               ssPtr->matchSum = (ZSTD_LITFREQ_ADD << Litbits);
+
+               for (u = 0; u <= MaxLit; u++) {
+                       ssPtr->litFreq[u] = 1 + (ssPtr->litFreq[u] >> ZSTD_FREQ_DIV);
+                       ssPtr->litSum += ssPtr->litFreq[u];
+               }
+               for (u = 0; u <= MaxLL; u++)
+                       ssPtr->litLengthFreq[u] = 1;
+               for (u = 0; u <= MaxML; u++)
+                       ssPtr->matchLengthFreq[u] = 1;
+               for (u = 0; u <= MaxOff; u++)
+                       ssPtr->offCodeFreq[u] = 1;
+       } else {
+               ssPtr->matchLengthSum = 0;
+               ssPtr->litLengthSum = 0;
+               ssPtr->offCodeSum = 0;
+               ssPtr->matchSum = 0;
+               ssPtr->litSum = 0;
+
+               for (u = 0; u <= MaxLit; u++) {
+                       ssPtr->litFreq[u] = 1 + (ssPtr->litFreq[u] >> (ZSTD_FREQ_DIV + 1));
+                       ssPtr->litSum += ssPtr->litFreq[u];
+               }
+               for (u = 0; u <= MaxLL; u++) {
+                       ssPtr->litLengthFreq[u] = 1 + (ssPtr->litLengthFreq[u] >> (ZSTD_FREQ_DIV + 1));
+                       ssPtr->litLengthSum += ssPtr->litLengthFreq[u];
+               }
+               for (u = 0; u <= MaxML; u++) {
+                       ssPtr->matchLengthFreq[u] = 1 + (ssPtr->matchLengthFreq[u] >> ZSTD_FREQ_DIV);
+                       ssPtr->matchLengthSum += ssPtr->matchLengthFreq[u];
+                       ssPtr->matchSum += ssPtr->matchLengthFreq[u] * (u + 3);
+               }
+               ssPtr->matchSum *= ZSTD_LITFREQ_ADD;
+               for (u = 0; u <= MaxOff; u++) {
+                       ssPtr->offCodeFreq[u] = 1 + (ssPtr->offCodeFreq[u] >> ZSTD_FREQ_DIV);
+                       ssPtr->offCodeSum += ssPtr->offCodeFreq[u];
+               }
+       }
+
+       ZSTD_setLog2Prices(ssPtr);
+}
+
+FORCE_INLINE U32 ZSTD_getLiteralPrice(seqStore_t *ssPtr, U32 litLength, const BYTE *literals)
+{
+       U32 price, u;
+
+       if (ssPtr->staticPrices)
+               return ZSTD_highbit32((U32)litLength + 1) + (litLength * 6);
+
+       if (litLength == 0)
+               return ssPtr->log2litLengthSum - ZSTD_highbit32(ssPtr->litLengthFreq[0] + 1);
+
+       /* literals */
+       if (ssPtr->cachedLiterals == literals) {
+               U32 const additional = litLength - ssPtr->cachedLitLength;
+               const BYTE *literals2 = ssPtr->cachedLiterals + ssPtr->cachedLitLength;
+               price = ssPtr->cachedPrice + additional * ssPtr->log2litSum;
+               for (u = 0; u < additional; u++)
+                       price -= ZSTD_highbit32(ssPtr->litFreq[literals2[u]] + 1);
+               ssPtr->cachedPrice = price;
+               ssPtr->cachedLitLength = litLength;
+       } else {
+               price = litLength * ssPtr->log2litSum;
+               for (u = 0; u < litLength; u++)
+                       price -= ZSTD_highbit32(ssPtr->litFreq[literals[u]] + 1);
+
+               if (litLength >= 12) {
+                       ssPtr->cachedLiterals = literals;
+                       ssPtr->cachedPrice = price;
+                       ssPtr->cachedLitLength = litLength;
+               }
+       }
+
+       /* literal Length */
+       {
+               const BYTE LL_deltaCode = 19;
+               const BYTE llCode = (litLength > 63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
+               price += LL_bits[llCode] + ssPtr->log2litLengthSum - ZSTD_highbit32(ssPtr->litLengthFreq[llCode] + 1);
+       }
+
+       return price;
+}
+
+FORCE_INLINE U32 ZSTD_getPrice(seqStore_t *seqStorePtr, U32 litLength, const BYTE *literals, U32 offset, U32 matchLength, const int ultra)
+{
+       /* offset */
+       U32 price;
+       BYTE const offCode = (BYTE)ZSTD_highbit32(offset + 1);
+
+       if (seqStorePtr->staticPrices)
+               return ZSTD_getLiteralPrice(seqStorePtr, litLength, literals) + ZSTD_highbit32((U32)matchLength + 1) + 16 + offCode;
+
+       price = offCode + seqStorePtr->log2offCodeSum - ZSTD_highbit32(seqStorePtr->offCodeFreq[offCode] + 1);
+       if (!ultra && offCode >= 20)
+               price += (offCode - 19) * 2;
+
+       /* match Length */
+       {
+               const BYTE ML_deltaCode = 36;
+               const BYTE mlCode = (matchLength > 127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
+               price += ML_bits[mlCode] + seqStorePtr->log2matchLengthSum - ZSTD_highbit32(seqStorePtr->matchLengthFreq[mlCode] + 1);
+       }
+
+       return price + ZSTD_getLiteralPrice(seqStorePtr, litLength, literals) + seqStorePtr->factor;
+}
+
+ZSTD_STATIC void ZSTD_updatePrice(seqStore_t *seqStorePtr, U32 litLength, const BYTE *literals, U32 offset, U32 matchLength)
+{
+       U32 u;
+
+       /* literals */
+       seqStorePtr->litSum += litLength * ZSTD_LITFREQ_ADD;
+       for (u = 0; u < litLength; u++)
+               seqStorePtr->litFreq[literals[u]] += ZSTD_LITFREQ_ADD;
+
+       /* literal Length */
+       {
+               const BYTE LL_deltaCode = 19;
+               const BYTE llCode = (litLength > 63) ? (BYTE)ZSTD_highbit32(litLength) + LL_deltaCode : LL_Code[litLength];
+               seqStorePtr->litLengthFreq[llCode]++;
+               seqStorePtr->litLengthSum++;
+       }
+
+       /* match offset */
+       {
+               BYTE const offCode = (BYTE)ZSTD_highbit32(offset + 1);
+               seqStorePtr->offCodeSum++;
+               seqStorePtr->offCodeFreq[offCode]++;
+       }
+
+       /* match Length */
+       {
+               const BYTE ML_deltaCode = 36;
+               const BYTE mlCode = (matchLength > 127) ? (BYTE)ZSTD_highbit32(matchLength) + ML_deltaCode : ML_Code[matchLength];
+               seqStorePtr->matchLengthFreq[mlCode]++;
+               seqStorePtr->matchLengthSum++;
+       }
+
+       ZSTD_setLog2Prices(seqStorePtr);
+}
+
+#define SET_PRICE(pos, mlen_, offset_, litlen_, price_)           \
+       {                                                         \
+               while (last_pos < pos) {                          \
+                       opt[last_pos + 1].price = ZSTD_MAX_PRICE; \
+                       last_pos++;                               \
+               }                                                 \
+               opt[pos].mlen = mlen_;                            \
+               opt[pos].off = offset_;                           \
+               opt[pos].litlen = litlen_;                        \
+               opt[pos].price = price_;                          \
+       }
+
+/* Update hashTable3 up to ip (excluded)
+   Assumption : always within prefix (i.e. not within extDict) */
+FORCE_INLINE
+U32 ZSTD_insertAndFindFirstIndexHash3(ZSTD_CCtx *zc, const BYTE *ip)
+{
+       U32 *const hashTable3 = zc->hashTable3;
+       U32 const hashLog3 = zc->hashLog3;
+       const BYTE *const base = zc->base;
+       U32 idx = zc->nextToUpdate3;
+       const U32 target = zc->nextToUpdate3 = (U32)(ip - base);
+       const size_t hash3 = ZSTD_hash3Ptr(ip, hashLog3);
+
+       while (idx < target) {
+               hashTable3[ZSTD_hash3Ptr(base + idx, hashLog3)] = idx;
+               idx++;
+       }
+
+       return hashTable3[hash3];
+}
+
+/*-*************************************
+*  Binary Tree search
+***************************************/
+static U32 ZSTD_insertBtAndGetAllMatches(ZSTD_CCtx *zc, const BYTE *const ip, const BYTE *const iLimit, U32 nbCompares, const U32 mls, U32 extDict,
+                                        ZSTD_match_t *matches, const U32 minMatchLen)
+{
+       const BYTE *const base = zc->base;
+       const U32 curr = (U32)(ip - base);
+       const U32 hashLog = zc->params.cParams.hashLog;
+       const size_t h = ZSTD_hashPtr(ip, hashLog, mls);
+       U32 *const hashTable = zc->hashTable;
+       U32 matchIndex = hashTable[h];
+       U32 *const bt = zc->chainTable;
+       const U32 btLog = zc->params.cParams.chainLog - 1;
+       const U32 btMask = (1U << btLog) - 1;
+       size_t commonLengthSmaller = 0, commonLengthLarger = 0;
+       const BYTE *const dictBase = zc->dictBase;
+       const U32 dictLimit = zc->dictLimit;
+       const BYTE *const dictEnd = dictBase + dictLimit;
+       const BYTE *const prefixStart = base + dictLimit;
+       const U32 btLow = btMask >= curr ? 0 : curr - btMask;
+       const U32 windowLow = zc->lowLimit;
+       U32 *smallerPtr = bt + 2 * (curr & btMask);
+       U32 *largerPtr = bt + 2 * (curr & btMask) + 1;
+       U32 matchEndIdx = curr + 8;
+       U32 dummy32; /* to be nullified at the end */
+       U32 mnum = 0;
+
+       const U32 minMatch = (mls == 3) ? 3 : 4;
+       size_t bestLength = minMatchLen - 1;
+
+       if (minMatch == 3) { /* HC3 match finder */
+               U32 const matchIndex3 = ZSTD_insertAndFindFirstIndexHash3(zc, ip);
+               if (matchIndex3 > windowLow && (curr - matchIndex3 < (1 << 18))) {
+                       const BYTE *match;
+                       size_t currMl = 0;
+                       if ((!extDict) || matchIndex3 >= dictLimit) {
+                               match = base + matchIndex3;
+                               if (match[bestLength] == ip[bestLength])
+                                       currMl = ZSTD_count(ip, match, iLimit);
+                       } else {
+                               match = dictBase + matchIndex3;
+                               if (ZSTD_readMINMATCH(match, MINMATCH) ==
+                                   ZSTD_readMINMATCH(ip, MINMATCH)) /* assumption : matchIndex3 <= dictLimit-4 (by table construction) */
+                                       currMl = ZSTD_count_2segments(ip + MINMATCH, match + MINMATCH, iLimit, dictEnd, prefixStart) + MINMATCH;
+                       }
+
+                       /* save best solution */
+                       if (currMl > bestLength) {
+                               bestLength = currMl;
+                               matches[mnum].off = ZSTD_REP_MOVE_OPT + curr - matchIndex3;
+                               matches[mnum].len = (U32)currMl;
+                               mnum++;
+                               if (currMl > ZSTD_OPT_NUM)
+                                       goto update;
+                               if (ip + currMl == iLimit)
+                                       goto update; /* best possible, and avoid read overflow*/
+                       }
+               }
+       }
+
+       hashTable[h] = curr; /* Update Hash Table */
+
+       while (nbCompares-- && (matchIndex > windowLow)) {
+               U32 *nextPtr = bt + 2 * (matchIndex & btMask);
+               size_t matchLength = MIN(commonLengthSmaller, commonLengthLarger); /* guaranteed minimum nb of common bytes */
+               const BYTE *match;
+
+               if ((!extDict) || (matchIndex + matchLength >= dictLimit)) {
+                       match = base + matchIndex;
+                       if (match[matchLength] == ip[matchLength]) {
+                               matchLength += ZSTD_count(ip + matchLength + 1, match + matchLength + 1, iLimit) + 1;
+                       }
+               } else {
+                       match = dictBase + matchIndex;
+                       matchLength += ZSTD_count_2segments(ip + matchLength, match + matchLength, iLimit, dictEnd, prefixStart);
+                       if (matchIndex + matchLength >= dictLimit)
+                               match = base + matchIndex; /* to prepare for next usage of match[matchLength] */
+               }
+
+               if (matchLength > bestLength) {
+                       if (matchLength > matchEndIdx - matchIndex)
+                               matchEndIdx = matchIndex + (U32)matchLength;
+                       bestLength = matchLength;
+                       matches[mnum].off = ZSTD_REP_MOVE_OPT + curr - matchIndex;
+                       matches[mnum].len = (U32)matchLength;
+                       mnum++;
+                       if (matchLength > ZSTD_OPT_NUM)
+                               break;
+                       if (ip + matchLength == iLimit) /* equal : no way to know if inf or sup */
+                               break;                  /* drop, to guarantee consistency (miss a little bit of compression) */
+               }
+
+               if (match[matchLength] < ip[matchLength]) {
+                       /* match is smaller than curr */
+                       *smallerPtr = matchIndex;         /* update smaller idx */
+                       commonLengthSmaller = matchLength; /* all smaller will now have at least this guaranteed common length */
+                       if (matchIndex <= btLow) {
+                               smallerPtr = &dummy32;
+                               break;
+                       }                         /* beyond tree size, stop the search */
+                       smallerPtr = nextPtr + 1; /* new "smaller" => larger of match */
+                       matchIndex = nextPtr[1];  /* new matchIndex larger than previous (closer to curr) */
+               } else {
+                       /* match is larger than curr */
+                       *largerPtr = matchIndex;
+                       commonLengthLarger = matchLength;
+                       if (matchIndex <= btLow) {
+                               largerPtr = &dummy32;
+                               break;
+                       } /* beyond tree size, stop the search */
+                       largerPtr = nextPtr;
+                       matchIndex = nextPtr[0];
+               }
+       }
+
+       *smallerPtr = *largerPtr = 0;
+
+update:
+       zc->nextToUpdate = (matchEndIdx > curr + 8) ? matchEndIdx - 8 : curr + 1;
+       return mnum;
+}
+
+/** Tree updater, providing best match */
+static U32 ZSTD_BtGetAllMatches(ZSTD_CCtx *zc, const BYTE *const ip, const BYTE *const iLimit, const U32 maxNbAttempts, const U32 mls, ZSTD_match_t *matches,
+                               const U32 minMatchLen)
+{
+       if (ip < zc->base + zc->nextToUpdate)
+               return 0; /* skipped area */
+       ZSTD_updateTree(zc, ip, iLimit, maxNbAttempts, mls);
+       return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 0, matches, minMatchLen);
+}
+
+static U32 ZSTD_BtGetAllMatches_selectMLS(ZSTD_CCtx *zc, /* Index table will be updated */
+                                         const BYTE *ip, const BYTE *const iHighLimit, const U32 maxNbAttempts, const U32 matchLengthSearch,
+                                         ZSTD_match_t *matches, const U32 minMatchLen)
+{
+       switch (matchLengthSearch) {
+       case 3: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
+       default:
+       case 4: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
+       case 5: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
+       case 7:
+       case 6: return ZSTD_BtGetAllMatches(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
+       }
+}
+
+/** Tree updater, providing best match */
+static U32 ZSTD_BtGetAllMatches_extDict(ZSTD_CCtx *zc, const BYTE *const ip, const BYTE *const iLimit, const U32 maxNbAttempts, const U32 mls,
+                                       ZSTD_match_t *matches, const U32 minMatchLen)
+{
+       if (ip < zc->base + zc->nextToUpdate)
+               return 0; /* skipped area */
+       ZSTD_updateTree_extDict(zc, ip, iLimit, maxNbAttempts, mls);
+       return ZSTD_insertBtAndGetAllMatches(zc, ip, iLimit, maxNbAttempts, mls, 1, matches, minMatchLen);
+}
+
+static U32 ZSTD_BtGetAllMatches_selectMLS_extDict(ZSTD_CCtx *zc, /* Index table will be updated */
+                                                 const BYTE *ip, const BYTE *const iHighLimit, const U32 maxNbAttempts, const U32 matchLengthSearch,
+                                                 ZSTD_match_t *matches, const U32 minMatchLen)
+{
+       switch (matchLengthSearch) {
+       case 3: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 3, matches, minMatchLen);
+       default:
+       case 4: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 4, matches, minMatchLen);
+       case 5: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 5, matches, minMatchLen);
+       case 7:
+       case 6: return ZSTD_BtGetAllMatches_extDict(zc, ip, iHighLimit, maxNbAttempts, 6, matches, minMatchLen);
+       }
+}
+
+/*-*******************************
+*  Optimal parser
+*********************************/
+FORCE_INLINE
+void ZSTD_compressBlock_opt_generic(ZSTD_CCtx *ctx, const void *src, size_t srcSize, const int ultra)
+{
+       seqStore_t *seqStorePtr = &(ctx->seqStore);
+       const BYTE *const istart = (const BYTE *)src;
+       const BYTE *ip = istart;
+       const BYTE *anchor = istart;
+       const BYTE *const iend = istart + srcSize;
+       const BYTE *const ilimit = iend - 8;
+       const BYTE *const base = ctx->base;
+       const BYTE *const prefixStart = base + ctx->dictLimit;
+
+       const U32 maxSearches = 1U << ctx->params.cParams.searchLog;
+       const U32 sufficient_len = ctx->params.cParams.targetLength;
+       const U32 mls = ctx->params.cParams.searchLength;
+       const U32 minMatch = (ctx->params.cParams.searchLength == 3) ? 3 : 4;
+
+       ZSTD_optimal_t *opt = seqStorePtr->priceTable;
+       ZSTD_match_t *matches = seqStorePtr->matchTable;
+       const BYTE *inr;
+       U32 offset, rep[ZSTD_REP_NUM];
+
+       /* init */
+       ctx->nextToUpdate3 = ctx->nextToUpdate;
+       ZSTD_rescaleFreqs(seqStorePtr, (const BYTE *)src, srcSize);
+       ip += (ip == prefixStart);
+       {
+               U32 i;
+               for (i = 0; i < ZSTD_REP_NUM; i++)
+                       rep[i] = ctx->rep[i];
+       }
+
+       /* Match Loop */
+       while (ip < ilimit) {
+               U32 cur, match_num, last_pos, litlen, price;
+               U32 u, mlen, best_mlen, best_off, litLength;
+               memset(opt, 0, sizeof(ZSTD_optimal_t));
+               last_pos = 0;
+               litlen = (U32)(ip - anchor);
+
+               /* check repCode */
+               {
+                       U32 i, last_i = ZSTD_REP_CHECK + (ip == anchor);
+                       for (i = (ip == anchor); i < last_i; i++) {
+                               const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
+                               if ((repCur > 0) && (repCur < (S32)(ip - prefixStart)) &&
+                                   (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(ip - repCur, minMatch))) {
+                                       mlen = (U32)ZSTD_count(ip + minMatch, ip + minMatch - repCur, iend) + minMatch;
+                                       if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
+                                               best_mlen = mlen;
+                                               best_off = i;
+                                               cur = 0;
+                                               last_pos = 1;
+                                               goto _storeSequence;
+                                       }
+                                       best_off = i - (ip == anchor);
+                                       do {
+                                               price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
+                                               if (mlen > last_pos || price < opt[mlen].price)
+                                                       SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
+                                               mlen--;
+                                       } while (mlen >= minMatch);
+                               }
+                       }
+               }
+
+               match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, ip, iend, maxSearches, mls, matches, minMatch);
+
+               if (!last_pos && !match_num) {
+                       ip++;
+                       continue;
+               }
+
+               if (match_num && (matches[match_num - 1].len > sufficient_len || matches[match_num - 1].len >= ZSTD_OPT_NUM)) {
+                       best_mlen = matches[match_num - 1].len;
+                       best_off = matches[match_num - 1].off;
+                       cur = 0;
+                       last_pos = 1;
+                       goto _storeSequence;
+               }
+
+               /* set prices using matches at position = 0 */
+               best_mlen = (last_pos) ? last_pos : minMatch;
+               for (u = 0; u < match_num; u++) {
+                       mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen;
+                       best_mlen = matches[u].len;
+                       while (mlen <= best_mlen) {
+                               price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra);
+                               if (mlen > last_pos || price < opt[mlen].price)
+                                       SET_PRICE(mlen, mlen, matches[u].off, litlen, price); /* note : macro modifies last_pos */
+                               mlen++;
+                       }
+               }
+
+               if (last_pos < minMatch) {
+                       ip++;
+                       continue;
+               }
+
+               /* initialize opt[0] */
+               {
+                       U32 i;
+                       for (i = 0; i < ZSTD_REP_NUM; i++)
+                               opt[0].rep[i] = rep[i];
+               }
+               opt[0].mlen = 1;
+               opt[0].litlen = litlen;
+
+               /* check further positions */
+               for (cur = 1; cur <= last_pos; cur++) {
+                       inr = ip + cur;
+
+                       if (opt[cur - 1].mlen == 1) {
+                               litlen = opt[cur - 1].litlen + 1;
+                               if (cur > litlen) {
+                                       price = opt[cur - litlen].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - litlen);
+                               } else
+                                       price = ZSTD_getLiteralPrice(seqStorePtr, litlen, anchor);
+                       } else {
+                               litlen = 1;
+                               price = opt[cur - 1].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - 1);
+                       }
+
+                       if (cur > last_pos || price <= opt[cur].price)
+                               SET_PRICE(cur, 1, 0, litlen, price);
+
+                       if (cur == last_pos)
+                               break;
+
+                       if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */
+                               continue;
+
+                       mlen = opt[cur].mlen;
+                       if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
+                               opt[cur].rep[2] = opt[cur - mlen].rep[1];
+                               opt[cur].rep[1] = opt[cur - mlen].rep[0];
+                               opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
+                       } else {
+                               opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur - mlen].rep[1] : opt[cur - mlen].rep[2];
+                               opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur - mlen].rep[0] : opt[cur - mlen].rep[1];
+                               opt[cur].rep[0] =
+                                   ((opt[cur].off == ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur - mlen].rep[0] - 1) : (opt[cur - mlen].rep[opt[cur].off]);
+                       }
+
+                       best_mlen = minMatch;
+                       {
+                               U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
+                               for (i = (opt[cur].mlen != 1); i < last_i; i++) { /* check rep */
+                                       const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i];
+                                       if ((repCur > 0) && (repCur < (S32)(inr - prefixStart)) &&
+                                           (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(inr - repCur, minMatch))) {
+                                               mlen = (U32)ZSTD_count(inr + minMatch, inr + minMatch - repCur, iend) + minMatch;
+
+                                               if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
+                                                       best_mlen = mlen;
+                                                       best_off = i;
+                                                       last_pos = cur + 1;
+                                                       goto _storeSequence;
+                                               }
+
+                                               best_off = i - (opt[cur].mlen != 1);
+                                               if (mlen > best_mlen)
+                                                       best_mlen = mlen;
+
+                                               do {
+                                                       if (opt[cur].mlen == 1) {
+                                                               litlen = opt[cur].litlen;
+                                                               if (cur > litlen) {
+                                                                       price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, inr - litlen,
+                                                                                                                       best_off, mlen - MINMATCH, ultra);
+                                                               } else
+                                                                       price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
+                                                       } else {
+                                                               litlen = 0;
+                                                               price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
+                                                       }
+
+                                                       if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
+                                                               SET_PRICE(cur + mlen, mlen, i, litlen, price);
+                                                       mlen--;
+                                               } while (mlen >= minMatch);
+                                       }
+                               }
+                       }
+
+                       match_num = ZSTD_BtGetAllMatches_selectMLS(ctx, inr, iend, maxSearches, mls, matches, best_mlen);
+
+                       if (match_num > 0 && (matches[match_num - 1].len > sufficient_len || cur + matches[match_num - 1].len >= ZSTD_OPT_NUM)) {
+                               best_mlen = matches[match_num - 1].len;
+                               best_off = matches[match_num - 1].off;
+                               last_pos = cur + 1;
+                               goto _storeSequence;
+                       }
+
+                       /* set prices using matches at position = cur */
+                       for (u = 0; u < match_num; u++) {
+                               mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen;
+                               best_mlen = matches[u].len;
+
+                               while (mlen <= best_mlen) {
+                                       if (opt[cur].mlen == 1) {
+                                               litlen = opt[cur].litlen;
+                                               if (cur > litlen)
+                                                       price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, ip + cur - litlen,
+                                                                                                       matches[u].off - 1, mlen - MINMATCH, ultra);
+                                               else
+                                                       price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra);
+                                       } else {
+                                               litlen = 0;
+                                               price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, matches[u].off - 1, mlen - MINMATCH, ultra);
+                                       }
+
+                                       if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
+                                               SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
+
+                                       mlen++;
+                               }
+                       }
+               }
+
+               best_mlen = opt[last_pos].mlen;
+               best_off = opt[last_pos].off;
+               cur = last_pos - best_mlen;
+
+       /* store sequence */
+_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
+               opt[0].mlen = 1;
+
+               while (1) {
+                       mlen = opt[cur].mlen;
+                       offset = opt[cur].off;
+                       opt[cur].mlen = best_mlen;
+                       opt[cur].off = best_off;
+                       best_mlen = mlen;
+                       best_off = offset;
+                       if (mlen > cur)
+                               break;
+                       cur -= mlen;
+               }
+
+               for (u = 0; u <= last_pos;) {
+                       u += opt[u].mlen;
+               }
+
+               for (cur = 0; cur < last_pos;) {
+                       mlen = opt[cur].mlen;
+                       if (mlen == 1) {
+                               ip++;
+                               cur++;
+                               continue;
+                       }
+                       offset = opt[cur].off;
+                       cur += mlen;
+                       litLength = (U32)(ip - anchor);
+
+                       if (offset > ZSTD_REP_MOVE_OPT) {
+                               rep[2] = rep[1];
+                               rep[1] = rep[0];
+                               rep[0] = offset - ZSTD_REP_MOVE_OPT;
+                               offset--;
+                       } else {
+                               if (offset != 0) {
+                                       best_off = (offset == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
+                                       if (offset != 1)
+                                               rep[2] = rep[1];
+                                       rep[1] = rep[0];
+                                       rep[0] = best_off;
+                               }
+                               if (litLength == 0)
+                                       offset--;
+                       }
+
+                       ZSTD_updatePrice(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH);
+                       ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH);
+                       anchor = ip = ip + mlen;
+               }
+       } /* for (cur=0; cur < last_pos; ) */
+
+       /* Save reps for next block */
+       {
+               int i;
+               for (i = 0; i < ZSTD_REP_NUM; i++)
+                       ctx->repToConfirm[i] = rep[i];
+       }
+
+       /* Last Literals */
+       {
+               size_t const lastLLSize = iend - anchor;
+               memcpy(seqStorePtr->lit, anchor, lastLLSize);
+               seqStorePtr->lit += lastLLSize;
+       }
+}
+
+FORCE_INLINE
+void ZSTD_compressBlock_opt_extDict_generic(ZSTD_CCtx *ctx, const void *src, size_t srcSize, const int ultra)
+{
+       seqStore_t *seqStorePtr = &(ctx->seqStore);
+       const BYTE *const istart = (const BYTE *)src;
+       const BYTE *ip = istart;
+       const BYTE *anchor = istart;
+       const BYTE *const iend = istart + srcSize;
+       const BYTE *const ilimit = iend - 8;
+       const BYTE *const base = ctx->base;
+       const U32 lowestIndex = ctx->lowLimit;
+       const U32 dictLimit = ctx->dictLimit;
+       const BYTE *const prefixStart = base + dictLimit;
+       const BYTE *const dictBase = ctx->dictBase;
+       const BYTE *const dictEnd = dictBase + dictLimit;
+
+       const U32 maxSearches = 1U << ctx->params.cParams.searchLog;
+       const U32 sufficient_len = ctx->params.cParams.targetLength;
+       const U32 mls = ctx->params.cParams.searchLength;
+       const U32 minMatch = (ctx->params.cParams.searchLength == 3) ? 3 : 4;
+
+       ZSTD_optimal_t *opt = seqStorePtr->priceTable;
+       ZSTD_match_t *matches = seqStorePtr->matchTable;
+       const BYTE *inr;
+
+       /* init */
+       U32 offset, rep[ZSTD_REP_NUM];
+       {
+               U32 i;
+               for (i = 0; i < ZSTD_REP_NUM; i++)
+                       rep[i] = ctx->rep[i];
+       }
+
+       ctx->nextToUpdate3 = ctx->nextToUpdate;
+       ZSTD_rescaleFreqs(seqStorePtr, (const BYTE *)src, srcSize);
+       ip += (ip == prefixStart);
+
+       /* Match Loop */
+       while (ip < ilimit) {
+               U32 cur, match_num, last_pos, litlen, price;
+               U32 u, mlen, best_mlen, best_off, litLength;
+               U32 curr = (U32)(ip - base);
+               memset(opt, 0, sizeof(ZSTD_optimal_t));
+               last_pos = 0;
+               opt[0].litlen = (U32)(ip - anchor);
+
+               /* check repCode */
+               {
+                       U32 i, last_i = ZSTD_REP_CHECK + (ip == anchor);
+                       for (i = (ip == anchor); i < last_i; i++) {
+                               const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : rep[i];
+                               const U32 repIndex = (U32)(curr - repCur);
+                               const BYTE *const repBase = repIndex < dictLimit ? dictBase : base;
+                               const BYTE *const repMatch = repBase + repIndex;
+                               if ((repCur > 0 && repCur <= (S32)curr) &&
+                                   (((U32)((dictLimit - 1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
+                                   && (ZSTD_readMINMATCH(ip, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch))) {
+                                       /* repcode detected we should take it */
+                                       const BYTE *const repEnd = repIndex < dictLimit ? dictEnd : iend;
+                                       mlen = (U32)ZSTD_count_2segments(ip + minMatch, repMatch + minMatch, iend, repEnd, prefixStart) + minMatch;
+
+                                       if (mlen > sufficient_len || mlen >= ZSTD_OPT_NUM) {
+                                               best_mlen = mlen;
+                                               best_off = i;
+                                               cur = 0;
+                                               last_pos = 1;
+                                               goto _storeSequence;
+                                       }
+
+                                       best_off = i - (ip == anchor);
+                                       litlen = opt[0].litlen;
+                                       do {
+                                               price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
+                                               if (mlen > last_pos || price < opt[mlen].price)
+                                                       SET_PRICE(mlen, mlen, i, litlen, price); /* note : macro modifies last_pos */
+                                               mlen--;
+                                       } while (mlen >= minMatch);
+                               }
+                       }
+               }
+
+               match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, ip, iend, maxSearches, mls, matches, minMatch); /* first search (depth 0) */
+
+               if (!last_pos && !match_num) {
+                       ip++;
+                       continue;
+               }
+
+               {
+                       U32 i;
+                       for (i = 0; i < ZSTD_REP_NUM; i++)
+                               opt[0].rep[i] = rep[i];
+               }
+               opt[0].mlen = 1;
+
+               if (match_num && (matches[match_num - 1].len > sufficient_len || matches[match_num - 1].len >= ZSTD_OPT_NUM)) {
+                       best_mlen = matches[match_num - 1].len;
+                       best_off = matches[match_num - 1].off;
+                       cur = 0;
+                       last_pos = 1;
+                       goto _storeSequence;
+               }
+
+               best_mlen = (last_pos) ? last_pos : minMatch;
+
+               /* set prices using matches at position = 0 */
+               for (u = 0; u < match_num; u++) {
+                       mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen;
+                       best_mlen = matches[u].len;
+                       litlen = opt[0].litlen;
+                       while (mlen <= best_mlen) {
+                               price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra);
+                               if (mlen > last_pos || price < opt[mlen].price)
+                                       SET_PRICE(mlen, mlen, matches[u].off, litlen, price);
+                               mlen++;
+                       }
+               }
+
+               if (last_pos < minMatch) {
+                       ip++;
+                       continue;
+               }
+
+               /* check further positions */
+               for (cur = 1; cur <= last_pos; cur++) {
+                       inr = ip + cur;
+
+                       if (opt[cur - 1].mlen == 1) {
+                               litlen = opt[cur - 1].litlen + 1;
+                               if (cur > litlen) {
+                                       price = opt[cur - litlen].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - litlen);
+                               } else
+                                       price = ZSTD_getLiteralPrice(seqStorePtr, litlen, anchor);
+                       } else {
+                               litlen = 1;
+                               price = opt[cur - 1].price + ZSTD_getLiteralPrice(seqStorePtr, litlen, inr - 1);
+                       }
+
+                       if (cur > last_pos || price <= opt[cur].price)
+                               SET_PRICE(cur, 1, 0, litlen, price);
+
+                       if (cur == last_pos)
+                               break;
+
+                       if (inr > ilimit) /* last match must start at a minimum distance of 8 from oend */
+                               continue;
+
+                       mlen = opt[cur].mlen;
+                       if (opt[cur].off > ZSTD_REP_MOVE_OPT) {
+                               opt[cur].rep[2] = opt[cur - mlen].rep[1];
+                               opt[cur].rep[1] = opt[cur - mlen].rep[0];
+                               opt[cur].rep[0] = opt[cur].off - ZSTD_REP_MOVE_OPT;
+                       } else {
+                               opt[cur].rep[2] = (opt[cur].off > 1) ? opt[cur - mlen].rep[1] : opt[cur - mlen].rep[2];
+                               opt[cur].rep[1] = (opt[cur].off > 0) ? opt[cur - mlen].rep[0] : opt[cur - mlen].rep[1];
+                               opt[cur].rep[0] =
+                                   ((opt[cur].off == ZSTD_REP_MOVE_OPT) && (mlen != 1)) ? (opt[cur - mlen].rep[0] - 1) : (opt[cur - mlen].rep[opt[cur].off]);
+                       }
+
+                       best_mlen = minMatch;
+                       {
+                               U32 i, last_i = ZSTD_REP_CHECK + (mlen != 1);
+                               for (i = (mlen != 1); i < last_i; i++) {
+                                       const S32 repCur = (i == ZSTD_REP_MOVE_OPT) ? (opt[cur].rep[0] - 1) : opt[cur].rep[i];
+                                       const U32 repIndex = (U32)(curr + cur - repCur);
+                                       const BYTE *const repBase = repIndex < dictLimit ? dictBase : base;
+                                       const BYTE *const repMatch = repBase + repIndex;
+                                       if ((repCur > 0 && repCur <= (S32)(curr + cur)) &&
+                                           (((U32)((dictLimit - 1) - repIndex) >= 3) & (repIndex > lowestIndex)) /* intentional overflow */
+                                           && (ZSTD_readMINMATCH(inr, minMatch) == ZSTD_readMINMATCH(repMatch, minMatch))) {
+                                               /* repcode detected */
+                                               const BYTE *const repEnd = repIndex < dictLimit ? dictEnd : iend;
+                                               mlen = (U32)ZSTD_count_2segments(inr + minMatch, repMatch + minMatch, iend, repEnd, prefixStart) + minMatch;
+
+                                               if (mlen > sufficient_len || cur + mlen >= ZSTD_OPT_NUM) {
+                                                       best_mlen = mlen;
+                                                       best_off = i;
+                                                       last_pos = cur + 1;
+                                                       goto _storeSequence;
+                                               }
+
+                                               best_off = i - (opt[cur].mlen != 1);
+                                               if (mlen > best_mlen)
+                                                       best_mlen = mlen;
+
+                                               do {
+                                                       if (opt[cur].mlen == 1) {
+                                                               litlen = opt[cur].litlen;
+                                                               if (cur > litlen) {
+                                                                       price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, inr - litlen,
+                                                                                                                       best_off, mlen - MINMATCH, ultra);
+                                                               } else
+                                                                       price = ZSTD_getPrice(seqStorePtr, litlen, anchor, best_off, mlen - MINMATCH, ultra);
+                                                       } else {
+                                                               litlen = 0;
+                                                               price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, best_off, mlen - MINMATCH, ultra);
+                                                       }
+
+                                                       if (cur + mlen > last_pos || price <= opt[cur + mlen].price)
+                                                               SET_PRICE(cur + mlen, mlen, i, litlen, price);
+                                                       mlen--;
+                                               } while (mlen >= minMatch);
+                                       }
+                               }
+                       }
+
+                       match_num = ZSTD_BtGetAllMatches_selectMLS_extDict(ctx, inr, iend, maxSearches, mls, matches, minMatch);
+
+                       if (match_num > 0 && (matches[match_num - 1].len > sufficient_len || cur + matches[match_num - 1].len >= ZSTD_OPT_NUM)) {
+                               best_mlen = matches[match_num - 1].len;
+                               best_off = matches[match_num - 1].off;
+                               last_pos = cur + 1;
+                               goto _storeSequence;
+                       }
+
+                       /* set prices using matches at position = cur */
+                       for (u = 0; u < match_num; u++) {
+                               mlen = (u > 0) ? matches[u - 1].len + 1 : best_mlen;
+                               best_mlen = matches[u].len;
+
+                               while (mlen <= best_mlen) {
+                                       if (opt[cur].mlen == 1) {
+                                               litlen = opt[cur].litlen;
+                                               if (cur > litlen)
+                                                       price = opt[cur - litlen].price + ZSTD_getPrice(seqStorePtr, litlen, ip + cur - litlen,
+                                                                                                       matches[u].off - 1, mlen - MINMATCH, ultra);
+                                               else
+                                                       price = ZSTD_getPrice(seqStorePtr, litlen, anchor, matches[u].off - 1, mlen - MINMATCH, ultra);
+                                       } else {
+                                               litlen = 0;
+                                               price = opt[cur].price + ZSTD_getPrice(seqStorePtr, 0, NULL, matches[u].off - 1, mlen - MINMATCH, ultra);
+                                       }
+
+                                       if (cur + mlen > last_pos || (price < opt[cur + mlen].price))
+                                               SET_PRICE(cur + mlen, mlen, matches[u].off, litlen, price);
+
+                                       mlen++;
+                               }
+                       }
+               } /* for (cur = 1; cur <= last_pos; cur++) */
+
+               best_mlen = opt[last_pos].mlen;
+               best_off = opt[last_pos].off;
+               cur = last_pos - best_mlen;
+
+       /* store sequence */
+_storeSequence: /* cur, last_pos, best_mlen, best_off have to be set */
+               opt[0].mlen = 1;
+
+               while (1) {
+                       mlen = opt[cur].mlen;
+                       offset = opt[cur].off;
+                       opt[cur].mlen = best_mlen;
+                       opt[cur].off = best_off;
+                       best_mlen = mlen;
+                       best_off = offset;
+                       if (mlen > cur)
+                               break;
+                       cur -= mlen;
+               }
+
+               for (u = 0; u <= last_pos;) {
+                       u += opt[u].mlen;
+               }
+
+               for (cur = 0; cur < last_pos;) {
+                       mlen = opt[cur].mlen;
+                       if (mlen == 1) {
+                               ip++;
+                               cur++;
+                               continue;
+                       }
+                       offset = opt[cur].off;
+                       cur += mlen;
+                       litLength = (U32)(ip - anchor);
+
+                       if (offset > ZSTD_REP_MOVE_OPT) {
+                               rep[2] = rep[1];
+                               rep[1] = rep[0];
+                               rep[0] = offset - ZSTD_REP_MOVE_OPT;
+                               offset--;
+                       } else {
+                               if (offset != 0) {
+                                       best_off = (offset == ZSTD_REP_MOVE_OPT) ? (rep[0] - 1) : (rep[offset]);
+                                       if (offset != 1)
+                                               rep[2] = rep[1];
+                                       rep[1] = rep[0];
+                                       rep[0] = best_off;
+                               }
+
+                               if (litLength == 0)
+                                       offset--;
+                       }
+
+                       ZSTD_updatePrice(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH);
+                       ZSTD_storeSeq(seqStorePtr, litLength, anchor, offset, mlen - MINMATCH);
+                       anchor = ip = ip + mlen;
+               }
+       } /* for (cur=0; cur < last_pos; ) */
+
+       /* Save reps for next block */
+       {
+               int i;
+               for (i = 0; i < ZSTD_REP_NUM; i++)
+                       ctx->repToConfirm[i] = rep[i];
+       }
+
+       /* Last Literals */
+       {
+               size_t lastLLSize = iend - anchor;
+               memcpy(seqStorePtr->lit, anchor, lastLLSize);
+               seqStorePtr->lit += lastLLSize;
+       }
+}
+
+#endif /* ZSTD_OPT_H_91842398743 */