typedef enum { ZSTD_lo_isRegularOffset, ZSTD_lo_isLongOffset=1 } ZSTD_longOffset_e;
+/**
+ * ZSTD_decodeSequence_old():
+ * @p longOffsets : tells the decoder to reload more bit while decoding large offsets
+ * only used in 32-bit mode
+ * @return : Sequence (litL + matchL + offset)
+ */
FORCE_INLINE_TEMPLATE seq_t
-ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
+ZSTD_decodeSequence_old(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
{
seq_t seq;
/*
- * ZSTD_seqSymbol is a structure with a total of 64 bits wide. So it can be
- * loaded in one operation and extracted its fields by simply shifting or
- * bit-extracting on aarch64.
+ * ZSTD_seqSymbol is a 64 bits wide structure.
+ * It can be loaded in one operation
+ * and its fields extracted by simply shifting or bit-extracting on aarch64.
* GCC doesn't recognize this and generates more unnecessary ldr/ldrb/ldrh
* operations that cause performance drop. This can be avoided by using this
* ZSTD_memcpy hack.
return seq;
}
+/**
+ * ZSTD_decodeSequence():
+ * @p longOffsets : tells the decoder to reload more bit while decoding large offsets
+ * only used in 32-bit mode
+ * @return : Sequence (litL + matchL + offset)
+ */
+FORCE_INLINE_TEMPLATE seq_t
+ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets, const int isLastSeq)
+{
+ seq_t seq;
+ /*
+ * ZSTD_seqSymbol is a 64 bits wide structure.
+ * It can be loaded in one operation
+ * and its fields extracted by simply shifting or bit-extracting on aarch64.
+ * GCC doesn't recognize this and generates more unnecessary ldr/ldrb/ldrh
+ * operations that cause performance drop. This can be avoided by using this
+ * ZSTD_memcpy hack.
+ */
+#if defined(__aarch64__) && (defined(__GNUC__) && !defined(__clang__))
+ ZSTD_seqSymbol llDInfoS, mlDInfoS, ofDInfoS;
+ ZSTD_seqSymbol* const llDInfo = &llDInfoS;
+ ZSTD_seqSymbol* const mlDInfo = &mlDInfoS;
+ ZSTD_seqSymbol* const ofDInfo = &ofDInfoS;
+ ZSTD_memcpy(llDInfo, seqState->stateLL.table + seqState->stateLL.state, sizeof(ZSTD_seqSymbol));
+ ZSTD_memcpy(mlDInfo, seqState->stateML.table + seqState->stateML.state, sizeof(ZSTD_seqSymbol));
+ ZSTD_memcpy(ofDInfo, seqState->stateOffb.table + seqState->stateOffb.state, sizeof(ZSTD_seqSymbol));
+#else
+ const ZSTD_seqSymbol* const llDInfo = seqState->stateLL.table + seqState->stateLL.state;
+ const ZSTD_seqSymbol* const mlDInfo = seqState->stateML.table + seqState->stateML.state;
+ const ZSTD_seqSymbol* const ofDInfo = seqState->stateOffb.table + seqState->stateOffb.state;
+#endif
+ seq.matchLength = mlDInfo->baseValue;
+ seq.litLength = llDInfo->baseValue;
+ { U32 const ofBase = ofDInfo->baseValue;
+ BYTE const llBits = llDInfo->nbAdditionalBits;
+ BYTE const mlBits = mlDInfo->nbAdditionalBits;
+ BYTE const ofBits = ofDInfo->nbAdditionalBits;
+ BYTE const totalBits = llBits+mlBits+ofBits;
+
+ U16 const llNext = llDInfo->nextState;
+ U16 const mlNext = mlDInfo->nextState;
+ U16 const ofNext = ofDInfo->nextState;
+ U32 const llnbBits = llDInfo->nbBits;
+ U32 const mlnbBits = mlDInfo->nbBits;
+ U32 const ofnbBits = ofDInfo->nbBits;
+
+ assert(llBits <= MaxLLBits);
+ assert(mlBits <= MaxMLBits);
+ assert(ofBits <= MaxOff);
+ /*
+ * As gcc has better branch and block analyzers, sometimes it is only
+ * valuable to mark likeliness for clang, it gives around 3-4% of
+ * performance.
+ */
+
+ /* sequence */
+ { size_t offset;
+ if (ofBits > 1) {
+ ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
+ ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
+ ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 > LONG_OFFSETS_MAX_EXTRA_BITS_32);
+ ZSTD_STATIC_ASSERT(STREAM_ACCUMULATOR_MIN_32 - LONG_OFFSETS_MAX_EXTRA_BITS_32 >= MaxMLBits);
+ if (MEM_32bits() && longOffsets && (ofBits >= STREAM_ACCUMULATOR_MIN_32)) {
+ /* Always read extra bits, this keeps the logic simple,
+ * avoids branches, and avoids accidentally reading 0 bits.
+ */
+ U32 const extraBits = LONG_OFFSETS_MAX_EXTRA_BITS_32;
+ offset = ofBase + (BIT_readBitsFast(&seqState->DStream, ofBits - extraBits) << extraBits);
+ BIT_reloadDStream(&seqState->DStream);
+ offset += BIT_readBitsFast(&seqState->DStream, extraBits);
+ } else {
+ offset = ofBase + BIT_readBitsFast(&seqState->DStream, ofBits/*>0*/); /* <= (ZSTD_WINDOWLOG_MAX-1) bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);
+ }
+ seqState->prevOffset[2] = seqState->prevOffset[1];
+ seqState->prevOffset[1] = seqState->prevOffset[0];
+ seqState->prevOffset[0] = offset;
+ } else {
+ U32 const ll0 = (llDInfo->baseValue == 0);
+ if (LIKELY((ofBits == 0))) {
+ offset = seqState->prevOffset[ll0];
+ seqState->prevOffset[1] = seqState->prevOffset[!ll0];
+ seqState->prevOffset[0] = offset;
+ } else {
+ offset = ofBase + ll0 + BIT_readBitsFast(&seqState->DStream, 1);
+ { size_t temp = (offset==3) ? seqState->prevOffset[0] - 1 : seqState->prevOffset[offset];
+ temp += !temp; /* 0 is not valid; input is corrupted; force offset to 1 */
+ if (offset != 1) seqState->prevOffset[2] = seqState->prevOffset[1];
+ seqState->prevOffset[1] = seqState->prevOffset[0];
+ seqState->prevOffset[0] = offset = temp;
+ } } }
+ seq.offset = offset;
+ }
+
+ if (mlBits > 0)
+ seq.matchLength += BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/);
+
+ if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
+ BIT_reloadDStream(&seqState->DStream);
+ if (MEM_64bits() && UNLIKELY(totalBits >= STREAM_ACCUMULATOR_MIN_64-(LLFSELog+MLFSELog+OffFSELog)))
+ BIT_reloadDStream(&seqState->DStream);
+ /* Ensure there are enough bits to read the rest of data in 64-bit mode. */
+ ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
+
+ if (llBits > 0)
+ seq.litLength += BIT_readBitsFast(&seqState->DStream, llBits/*>0*/);
+
+ if (MEM_32bits())
+ BIT_reloadDStream(&seqState->DStream);
+
+ DEBUGLOG(6, "seq: litL=%u, matchL=%u, offset=%u",
+ (U32)seq.litLength, (U32)seq.matchLength, (U32)seq.offset);
+
+ if (!isLastSeq) {
+ /* don't update FSE state for last Sequence */
+ ZSTD_updateFseStateWithDInfo(&seqState->stateLL, &seqState->DStream, llNext, llnbBits); /* <= 9 bits */
+ ZSTD_updateFseStateWithDInfo(&seqState->stateML, &seqState->DStream, mlNext, mlnbBits); /* <= 9 bits */
+ if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream); /* <= 18 bits */
+ ZSTD_updateFseStateWithDInfo(&seqState->stateOffb, &seqState->DStream, ofNext, ofnbBits); /* <= 8 bits */
+ BIT_reloadDStream(&seqState->DStream);
+ }
+ }
+
+ return seq;
+}
+
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
MEM_STATIC int ZSTD_dictionaryIsActive(ZSTD_DCtx const* dctx, BYTE const* prefixStart, BYTE const* oLitEnd)
{
/* decompress without overrunning litPtr begins */
{
- seq_t sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ seq_t sequence = ZSTD_decodeSequence_old(&seqState, isLongOffset);
/* Align the decompression loop to 32 + 16 bytes.
*
* zstd compiled with gcc-9 on an Intel i9-9900k shows 10% decompression
if (UNLIKELY(!--nbSeq))
break;
BIT_reloadDStream(&(seqState.DStream));
- sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ sequence = ZSTD_decodeSequence_old(&seqState, isLongOffset);
}
/* If there are more sequences, they will need to read literals from litExtraBuffer; copy over the remainder from dst and update litPtr and litEnd */
#endif
for (; ; ) {
- seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ seq_t const sequence = ZSTD_decodeSequence_old(&seqState, isLongOffset);
size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litBufferEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
assert(!ZSTD_isError(oneSeqSize));
# endif
#endif
- for ( ; ; ) {
- seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ for ( ; nbSeq ; nbSeq--) {
+ seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset, nbSeq==1);
size_t const oneSeqSize = ZSTD_execSequence(op, oend, sequence, &litPtr, litEnd, prefixStart, vBase, dictEnd);
#if defined(FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION) && defined(FUZZING_ASSERT_VALID_SEQUENCE)
assert(!ZSTD_isError(oneSeqSize));
return oneSeqSize;
DEBUGLOG(6, "regenerated sequence size : %u", (U32)oneSeqSize);
op += oneSeqSize;
- if (UNLIKELY(!--nbSeq))
- break;
- BIT_reloadDStream(&(seqState.DStream));
}
/* check if reached exact end */
DEBUGLOG(5, "ZSTD_decompressSequences_body: after decode loop, remaining nbSeq : %i", nbSeq);
RETURN_ERROR_IF(nbSeq, corruption_detected, "");
- RETURN_ERROR_IF(BIT_reloadDStream(&seqState.DStream) < BIT_DStream_completed, corruption_detected, "");
+ DEBUGLOG(5, "bitStream : start=%p, ptr=%p, bitsConsumed=%u", seqState.DStream.start, seqState.DStream.ptr, seqState.DStream.bitsConsumed);
+ RETURN_ERROR_IF(!BIT_endOfDStream(&seqState.DStream), corruption_detected, "");
/* save reps for next block */
{ U32 i; for (i=0; i<ZSTD_REP_NUM; i++) dctx->entropy.rep[i] = (U32)(seqState.prevOffset[i]); }
}
/* prepare in advance */
for (seqNb=0; (BIT_reloadDStream(&seqState.DStream) <= BIT_DStream_completed) && (seqNb<seqAdvance); seqNb++) {
- seq_t const sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ seq_t const sequence = ZSTD_decodeSequence_old(&seqState, isLongOffset);
prefetchPos = ZSTD_prefetchMatch(prefetchPos, sequence, prefixStart, dictEnd);
sequences[seqNb] = sequence;
}
/* decompress without stomping litBuffer */
for (; (BIT_reloadDStream(&(seqState.DStream)) <= BIT_DStream_completed) && (seqNb < nbSeq); seqNb++) {
- seq_t sequence = ZSTD_decodeSequence(&seqState, isLongOffset);
+ seq_t sequence = ZSTD_decodeSequence_old(&seqState, isLongOffset);
size_t oneSeqSize;
if (dctx->litBufferLocation == ZSTD_split && litPtr + sequences[(seqNb - ADVANCED_SEQS) & STORED_SEQS_MASK].litLength > dctx->litBufferEnd)
projects / thirdparty / zstd.git / commitdiff
