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support for ZSTD_REP_NUM=3

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This commit is contained in:
inikep
2016-04-05 10:30:05 +02:00
parent 74e3a7ba4c
commit ba73d1bb6b
4 changed files with 38 additions and 83 deletions
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lib/zstd_decompress.c
+21 -68
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@@ -656,51 +656,7 @@ static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState, const U32 mls)
0xFFFFFF, 0x1FFFFFF, 0x3FFFFFF, /*fake*/ 1, 1, 1, 1, 1 };
/* sequence */
#if ZSTD_REP_NUM == 1
#if 1
{ size_t const offset = ofCode ? OF_base[ofCode] + BIT_readBits(&(seqState->DStream), ofBits) - ZSTD_REP_MOVE : /* <= 26 bits */
llCode ? seq->offset : seqState->prevOffset[0];
if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
if (ofCode | !llCode) seqState->prevOffset[0] = seq->offset; /* cmove */
seq->offset = offset;
}
#else
{ size_t offset;
if (ofCode) {
offset = OF_base[ofCode] + BIT_readBits(&(seqState->DStream), ofBits) - ZSTD_REP_MOVE; /* <= 26 bits */
if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
seqState->prevOffset[0] = seq->offset; /* cmove */
} else {
if (llCode) {
offset = seq->offset;
} else {
offset = seqState->prevOffset[0];
seqState->prevOffset[0] = seq->offset;
}
}
seq->offset = offset;
}
#endif
#else // ZSTD_REP_NUM == 1
{ size_t offset;
#if 0
if (!ofCode) {
if (!llCode) {
offset = seqState->prevOffset[1];
seqState->prevOffset[1] = seqState->prevOffset[0];
seqState->prevOffset[0] = offset;
} else {
offset = seqState->prevOffset[0];
}
} else {
offset = OF_base[ofCode] + BIT_readBits(&(seqState->DStream), ofBits); /* <= 26 bits */
if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
#else
if (!ofCode)
offset = 0;
else {
@@ -708,37 +664,34 @@ static void ZSTD_decodeSequence(seq_t* seq, seqState_t* seqState, const U32 mls)
if (MEM_32bits()) BIT_reloadDStream(&(seqState->DStream));
}
{
if (offset < ZSTD_REP_NUM) {
if (llCode == 0 && offset <= 1) offset = 1-offset;
if (offset != 0) {
size_t temp = seqState->prevOffset[offset];
if (offset != 1) {
#if ZSTD_REP_NUM > 3
if (offset == 3) seqState->prevOffset[3] = seqState->prevOffset[2];
#endif
if (offset < ZSTD_REP_NUM) {
if (llCode == 0 && offset <= 1) offset = 1-offset;
if (offset != 0) {
size_t temp = seqState->prevOffset[offset];
if (offset != 1) {
if (offset == 3) seqState->prevOffset[3] = seqState->prevOffset[2];
seqState->prevOffset[2] = seqState->prevOffset[1];
}
seqState->prevOffset[1] = seqState->prevOffset[0];
seqState->prevOffset[0] = offset = temp;
} else {
offset = seqState->prevOffset[0];
seqState->prevOffset[2] = seqState->prevOffset[1];
}
seqState->prevOffset[1] = seqState->prevOffset[0];
seqState->prevOffset[0] = offset = temp;
} else {
offset -= ZSTD_REP_MOVE;
seqState->prevOffset[3] = seqState->prevOffset[2];
seqState->prevOffset[2] = seqState->prevOffset[1];
seqState->prevOffset[1] = seqState->prevOffset[0];
seqState->prevOffset[0] = offset;
offset = seqState->prevOffset[0];
}
} else {
offset -= ZSTD_REP_MOVE;
#if ZSTD_REP_NUM > 3
seqState->prevOffset[3] = seqState->prevOffset[2];
#endif
seqState->prevOffset[2] = seqState->prevOffset[1];
seqState->prevOffset[1] = seqState->prevOffset[0];
seqState->prevOffset[0] = offset;
}
seq->offset = offset;
}
#endif
seq->matchLength = ML_base[mlCode] + mls + ((mlCode>31) ? BIT_readBits(&(seqState->DStream), mlBits) : 0); /* <= 16 bits */
if (MEM_32bits() && (mlBits+llBits>24)) BIT_reloadDStream(&(seqState->DStream));