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Huffman ASM

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This commit is contained in:
Nick Terrell
2021-09-20 14:46:43 -07:00
parent 51b123d5f7
commit a5f2c45528
15 changed files with 1348 additions and 195 deletions
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lib/decompress/huf_decompress.c
+641 -114
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@@ -22,6 +22,13 @@
#define HUF_STATIC_LINKING_ONLY
#include "../common/huf.h"
#include "../common/error_private.h"
#include "../common/zstd_internal.h"
/* **************************************************************
* Constants
****************************************************************/
#define HUF_DECODER_FAST_TABLELOG 11
/* **************************************************************
* Macros
@@ -36,6 +43,40 @@
#error "Cannot force the use of the X1 and X2 decoders at the same time!"
#endif
/* Only use assembly on Linux / MacOS.
* Disable when MSAN is enabled.
*/
#if defined(__linux__) || defined(__linux) || defined(__APPLE__)
# if ZSTD_MEMORY_SANITIZER
# define HUF_ASM_SUPPORTED 0
# else
# define HUF_ASM_SUPPORTED 1
#endif
#else
# define HUF_ASM_SUPPORTED 0
#endif
/* HUF_DISABLE_ASM: Disables all ASM implementations. */
#if !defined(HUF_DISABLE_ASM) && \
HUF_ASM_SUPPORTED && \
defined(__x86_64__) && (DYNAMIC_BMI2 || defined(__BMI2__))
# define HUF_ENABLE_ASM_X86_64_BMI2 1
#else
# define HUF_ENABLE_ASM_X86_64_BMI2 0
#endif
#if HUF_ENABLE_ASM_X86_64_BMI2 && DYNAMIC_BMI2
# define HUF_ASM_X86_64_BMI2_ATTRS TARGET_ATTRIBUTE("bmi2")
#else
# define HUF_ASM_X86_64_BMI2_ATTRS
#endif
#ifdef __cplusplus
# define HUF_EXTERN_C extern "C"
#else
# define HUF_EXTERN_C
#endif
#define HUF_ASM_DECL HUF_EXTERN_C
/* **************************************************************
* Error Management
@@ -107,13 +148,146 @@ static DTableDesc HUF_getDTableDesc(const HUF_DTable* table)
return dtd;
}
#if HUF_ENABLE_ASM_X86_64_BMI2
static size_t HUF_initDStream(BYTE const* ip) {
BYTE const lastByte = ip[7];
size_t const bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
size_t const value = MEM_readLEST(ip) | 1;
assert(bitsConsumed <= 8);
return value << bitsConsumed;
}
typedef struct {
BYTE const* ip[4];
BYTE* op[4];
U64 bits[4];
void const* dt;
BYTE const* ilimit;
BYTE* oend;
BYTE const* iend[4];
} HUF_DecompressAsmArgs;
/**
* Initializes args for the asm decoding loop.
* @returns 0 on success
* 1 if the fallback implementation should be used.
* Or an error code on failure.
*/
static size_t HUF_DecompressAsmArgs_init(HUF_DecompressAsmArgs* args, void* dst, size_t dstSize, void const* src, size_t srcSize, const HUF_DTable* DTable)
{
void const* dt = DTable + 1;
U32 const dtLog = HUF_getDTableDesc(DTable).tableLog;
const BYTE* const ilimit = (const BYTE*)src + 6 + 8;
BYTE* const oend = (BYTE*)dst + dstSize;
/* We're assuming x86-64 BMI2 - assure that this is the case. */
assert(MEM_isLittleEndian() && !MEM_32bits());
/* strict minimum : jump table + 1 byte per stream */
if (srcSize < 10)
return ERROR(corruption_detected);
/* Must have at least 8 bytes per stream because we don't handle initializing smaller bit containers.
* If table log is not correct at this point, fallback to the old decoder.
* On small inputs we don't have enough data to trigger the fast loop, so use the old decoder.
*/
if (dtLog != HUF_DECODER_FAST_TABLELOG)
return 1;
/* Read the jump table. */
{
const BYTE* const istart = (const BYTE*)src;
size_t const length1 = MEM_readLE16(istart);
size_t const length2 = MEM_readLE16(istart+2);
size_t const length3 = MEM_readLE16(istart+4);
size_t const length4 = srcSize - (length1 + length2 + length3 + 6);
args->iend[0] = istart + 6; /* jumpTable */
args->iend[1] = args->iend[0] + length1;
args->iend[2] = args->iend[1] + length2;
args->iend[3] = args->iend[2] + length3;
/* HUF_initDStream() requires this, and this small of an input
* won't benefit from the ASM loop anyways.
* length1 must be >= 16 so that ip[0] >= ilimit before the loop
* starts.
*/
if (length1 < 16 || length2 < 8 || length3 < 8 || length4 < 8)
return 1;
if (length4 > srcSize) return ERROR(corruption_detected); /* overflow */
}
/* ip[] contains the position that is currently loaded into bits[]. */
args->ip[0] = args->iend[1] - sizeof(U64);
args->ip[1] = args->iend[2] - sizeof(U64);
args->ip[2] = args->iend[3] - sizeof(U64);
args->ip[3] = (BYTE const*)src + srcSize - sizeof(U64);
/* op[] contains the output pointers. */
args->op[0] = (BYTE*)dst;
args->op[1] = args->op[0] + (dstSize+3)/4;
args->op[2] = args->op[1] + (dstSize+3)/4;
args->op[3] = args->op[2] + (dstSize+3)/4;
/* No point to call the ASM loop for tiny outputs. */
if (args->op[3] >= oend)
return 1;
/* bits[] is the bit container.
* It is read from the MSB down to the LSB.
* It is shifted left as it is read, and zeros are
* shifted in. After the lowest valid bit a 1 is
* set, so that CountTrailingZeros(bits[]) can be used
* to count how many bits we've consumed.
*/
args->bits[0] = HUF_initDStream(args->ip[0]);
args->bits[1] = HUF_initDStream(args->ip[1]);
args->bits[2] = HUF_initDStream(args->ip[2]);
args->bits[3] = HUF_initDStream(args->ip[3]);
/* If ip[] >= ilimit, it is guaranteed to be safe to
* reload bits[]. It may be beyond its section, but is
* guaranteed to be valid (>= istart).
*/
args->ilimit = ilimit;
args->oend = oend;
args->dt = dt;
return 0;
}
static size_t HUF_initRemainingDStream(BIT_DStream_t* bit, HUF_DecompressAsmArgs const* args, int stream, BYTE* segmentEnd)
{
/* Validate that we haven't overwritten. */
if (args->op[stream] > segmentEnd)
return ERROR(corruption_detected);
/* Validate that we haven't read beyond iend[].
* Note that ip[] may be < iend[] because the MSB is
* the next bit to read, and we may have consumed 100%
* of the stream, so down to iend[i] - 8 is valid.
*/
if (args->ip[stream] < args->iend[stream] - 8)
return ERROR(corruption_detected);
/* Construct the BIT_DStream_t. */
bit->bitContainer = MEM_readLE64(args->ip[stream]);
bit->bitsConsumed = ZSTD_countTrailingZeros((size_t)args->bits[stream]);
bit->start = (const char*)args->iend[0];
bit->limitPtr = bit->start + sizeof(size_t);
bit->ptr = (const char*)args->ip[stream];
return 0;
}
#endif
#ifndef HUF_FORCE_DECOMPRESS_X2
/*-***************************/
/* single-symbol decoding */
/*-***************************/
typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX1; /* single-symbol decoding */
typedef struct { BYTE nbBits; BYTE byte; } HUF_DEltX1; /* single-symbol decoding */
/**
* Packs 4 HUF_DEltX1 structs into a U64. This is used to lay down 4 entries at
@@ -122,14 +296,44 @@ typedef struct { BYTE byte; BYTE nbBits; } HUF_DEltX1; /* single-symbol decodi
static U64 HUF_DEltX1_set4(BYTE symbol, BYTE nbBits) {
U64 D4;
if (MEM_isLittleEndian()) {
D4 = symbol + (nbBits << 8);
} else {
D4 = (symbol << 8) + nbBits;
} else {
D4 = symbol + (nbBits << 8);
}
D4 *= 0x0001000100010001ULL;
return D4;
}
/**
* Increase the tableLog to targetTableLog and rescales the stats.
* If tableLog > targetTableLog this is a no-op.
* @returns New tableLog
*/
static U32 HUF_rescaleStats(BYTE* huffWeight, U32* rankVal, U32 nbSymbols, U32 tableLog, U32 targetTableLog)
{
if (tableLog > targetTableLog)
return tableLog;
if (tableLog < targetTableLog) {
U32 const scale = targetTableLog - tableLog;
U32 s;
/* Increase the weight for all non-zero probability symbols by scale. */
for (s = 0; s < nbSymbols; ++s) {
huffWeight[s] += (BYTE)((huffWeight[s] == 0) ? 0 : scale);
}
/* Update rankVal to reflect the new weights.
* All weights except 0 get moved to weight + scale.
* Weights [1, scale] are empty.
*/
for (s = targetTableLog; s > scale; --s) {
rankVal[s] = rankVal[s - scale];
}
for (s = scale; s > 0; --s) {
rankVal[s] = 0;
}
}
return targetTableLog;
}
typedef struct {
U32 rankVal[HUF_TABLELOG_ABSOLUTEMAX + 1];
U32 rankStart[HUF_TABLELOG_ABSOLUTEMAX + 1];
@@ -162,8 +366,12 @@ size_t HUF_readDTableX1_wksp_bmi2(HUF_DTable* DTable, const void* src, size_t sr
iSize = HUF_readStats_wksp(wksp->huffWeight, HUF_SYMBOLVALUE_MAX + 1, wksp->rankVal, &nbSymbols, &tableLog, src, srcSize, wksp->statsWksp, sizeof(wksp->statsWksp), bmi2);
if (HUF_isError(iSize)) return iSize;
/* Table header */
{ DTableDesc dtd = HUF_getDTableDesc(DTable);
U32 const maxTableLog = dtd.maxTableLog + 1;
U32 const targetTableLog = MIN(maxTableLog, HUF_DECODER_FAST_TABLELOG);
tableLog = HUF_rescaleStats(wksp->huffWeight, wksp->rankVal, nbSymbols, tableLog, targetTableLog);
if (tableLog > (U32)(dtd.maxTableLog+1)) return ERROR(tableLog_tooLarge); /* DTable too small, Huffman tree cannot fit in */
dtd.tableType = 0;
dtd.tableLog = (BYTE)tableLog;
@@ -445,6 +653,77 @@ HUF_decompress4X1_usingDTable_internal_body(
}
}
#if DYNAMIC_BMI2
static TARGET_ATTRIBUTE("bmi2")
size_t HUF_decompress4X1_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc,
size_t cSrcSize, HUF_DTable const* DTable) {
return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}
#endif
static
size_t HUF_decompress4X1_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc,
size_t cSrcSize, HUF_DTable const* DTable) {
return HUF_decompress4X1_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}
#if HUF_ENABLE_ASM_X86_64_BMI2
HUF_ASM_DECL void HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop(HUF_DecompressAsmArgs* args);
static HUF_ASM_X86_64_BMI2_ATTRS
size_t
HUF_decompress4X1_usingDTable_internal_bmi2_asm(
void* dst, size_t dstSize,
const void* cSrc, size_t cSrcSize,
const HUF_DTable* DTable)
{
void const* dt = DTable + 1;
const BYTE* const iend = (const BYTE*)cSrc + 6;
BYTE* const oend = (BYTE*)dst + dstSize;
HUF_DecompressAsmArgs args;
{
size_t const ret = HUF_DecompressAsmArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable);
FORWARD_IF_ERROR(ret, "Failed to init asm args");
if (ret != 0)
return HUF_decompress4X1_usingDTable_internal_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);
}
assert(args.ip[0] >= args.ilimit);
HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop(&args);
/* Our loop guarantees that ip[] >= ilimit and that we haven't
* overwritten any op[].
*/
assert(args.ip[0] >= iend);
assert(args.ip[1] >= iend);
assert(args.ip[2] >= iend);
assert(args.ip[3] >= iend);
assert(args.op[3] <= oend);
(void)iend;
/* finish bit streams one by one. */
{
size_t const segmentSize = (dstSize+3) / 4;
BYTE* segmentEnd = (BYTE*)dst;
int i;
for (i = 0; i < 4; ++i) {
BIT_DStream_t bit;
if (segmentSize <= (size_t)(oend - segmentEnd))
segmentEnd += segmentSize;
else
segmentEnd = oend;
FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption");
/* Decompress and validate that we've produced exactly the expected length. */
args.op[i] += HUF_decodeStreamX1(args.op[i], &bit, segmentEnd, (HUF_DEltX1 const*)dt, HUF_DECODER_FAST_TABLELOG);
if (args.op[i] != segmentEnd) return ERROR(corruption_detected);
}
}
/* decoded size */
return dstSize;
}
#endif /* HUF_ENABLE_ASM_X86_64_BMI2 */
typedef size_t (*HUF_decompress_usingDTable_t)(void *dst, size_t dstSize,
const void *cSrc,
@@ -452,8 +731,28 @@ typedef size_t (*HUF_decompress_usingDTable_t)(void *dst, size_t dstSize,
const HUF_DTable *DTable);
HUF_DGEN(HUF_decompress1X1_usingDTable_internal)
HUF_DGEN(HUF_decompress4X1_usingDTable_internal)
static size_t HUF_decompress4X1_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc,
size_t cSrcSize, HUF_DTable const* DTable, int bmi2)
{
#if DYNAMIC_BMI2
if (bmi2) {
# if HUF_ENABLE_ASM_X86_64_BMI2
return HUF_decompress4X1_usingDTable_internal_bmi2_asm(dst, dstSize, cSrc, cSrcSize, DTable);
# else
return HUF_decompress4X1_usingDTable_internal_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);
# endif
}
#else
(void)bmi2;
#endif
#if HUF_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__)
return HUF_decompress4X1_usingDTable_internal_bmi2_asm(dst, dstSize, cSrc, cSrcSize, DTable);
#else
return HUF_decompress4X1_usingDTable_internal_default(dst, dstSize, cSrc, cSrcSize, DTable);
#endif
}
size_t HUF_decompress1X1_usingDTable(
@@ -523,106 +822,226 @@ size_t HUF_decompress4X1_DCtx_wksp(HUF_DTable* dctx, void* dst, size_t dstSize,
/* *************************/
typedef struct { U16 sequence; BYTE nbBits; BYTE length; } HUF_DEltX2; /* double-symbols decoding */
typedef struct { BYTE symbol; BYTE weight; } sortedSymbol_t;
typedef struct { BYTE symbol; } sortedSymbol_t;
typedef U32 rankValCol_t[HUF_TABLELOG_MAX + 1];
typedef rankValCol_t rankVal_t[HUF_TABLELOG_MAX];
/**
* Constructs a HUF_DEltX2 in a U32.
*/
static U32 HUF_buildDEltX2U32(U32 symbol, U32 nbBits, U32 baseSeq, int level)
{
U32 seq;
DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, sequence) == 0);
DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, nbBits) == 2);
DEBUG_STATIC_ASSERT(offsetof(HUF_DEltX2, length) == 3);
DEBUG_STATIC_ASSERT(sizeof(HUF_DEltX2) == sizeof(U32));
if (MEM_isLittleEndian()) {
seq = level == 1 ? symbol : (baseSeq + (symbol << 8));
return seq + (nbBits << 16) + ((U32)level << 24);
} else {
seq = level == 1 ? (symbol << 8) : ((baseSeq << 8) + symbol);
return (seq << 16) + (nbBits << 8) + (U32)level;
}
}
/**
* Constructs a HUF_DEltX2.
*/
static HUF_DEltX2 HUF_buildDEltX2(U32 symbol, U32 nbBits, U32 baseSeq, int level)
{
HUF_DEltX2 DElt;
U32 const val = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level);
DEBUG_STATIC_ASSERT(sizeof(DElt) == sizeof(val));
ZSTD_memcpy(&DElt, &val, sizeof(val));
return DElt;
}
/**
* Constructs 2 HUF_DEltX2s and packs them into a U64.
*/
static U64 HUF_buildDEltX2U64(U32 symbol, U32 nbBits, U16 baseSeq, int level)
{
U32 DElt = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level);
return (U64)DElt + ((U64)DElt << 32);
}
/**
* Fills the DTable rank with all the symbols from [begin, end) that are each
* nbBits long.
*
* @param DTableRank The start of the rank in the DTable.
* @param begin The first symbol to fill (inclusive).
* @param end The last symbol to fill (exclusive).
* @param nbBits Each symbol is nbBits long.
* @param tableLog The table log.
* @param baseSeq If level == 1 { 0 } else { the first level symbol }
* @param level The level in the table. Must be 1 or 2.
*/
static void HUF_fillDTableX2ForWeight(
HUF_DEltX2* DTableRank,
sortedSymbol_t const* begin, sortedSymbol_t const* end,
U32 nbBits, U32 tableLog,
U16 baseSeq, int const level)
{
U32 const length = 1U << ((tableLog - nbBits) & 0x1F /* quiet static-analyzer */);
const sortedSymbol_t* ptr;
assert(level >= 1 && level <= 2);
switch (length) {
case 1:
for (ptr = begin; ptr != end; ++ptr) {
HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level);
*DTableRank++ = DElt;
}
break;
case 2:
for (ptr = begin; ptr != end; ++ptr) {
HUF_DEltX2 const DElt = HUF_buildDEltX2(ptr->symbol, nbBits, baseSeq, level);
DTableRank[0] = DElt;
DTableRank[1] = DElt;
DTableRank += 2;
}
break;
case 4:
for (ptr = begin; ptr != end; ++ptr) {
U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level);
ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2));
DTableRank += 4;
}
break;
case 8:
for (ptr = begin; ptr != end; ++ptr) {
U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level);
ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2));
DTableRank += 8;
}
break;
default:
for (ptr = begin; ptr != end; ++ptr) {
U64 const DEltX2 = HUF_buildDEltX2U64(ptr->symbol, nbBits, baseSeq, level);
HUF_DEltX2* const DTableRankEnd = DTableRank + length;
for (; DTableRank != DTableRankEnd; DTableRank += 8) {
ZSTD_memcpy(DTableRank + 0, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 2, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 4, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTableRank + 6, &DEltX2, sizeof(DEltX2));
}
}
break;
}
}
/* HUF_fillDTableX2Level2() :
* `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */
static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 sizeLog, const U32 consumed,
const U32* rankValOrigin, const int minWeight,
const sortedSymbol_t* sortedSymbols, const U32 sortedListSize,
U32 nbBitsBaseline, U16 baseSeq, U32* wksp, size_t wkspSize)
static void HUF_fillDTableX2Level2(HUF_DEltX2* DTable, U32 targetLog, const U32 consumedBits,
const U32* rankVal, const int minWeight, const int maxWeight1,
const sortedSymbol_t* sortedSymbols, U32 const* rankStart,
U32 nbBitsBaseline, U16 baseSeq)
{
HUF_DEltX2 DElt;
U32* rankVal = wksp;
assert(wkspSize >= HUF_TABLELOG_MAX + 1);
(void)wkspSize;
/* get pre-calculated rankVal */
ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1));
/* fill skipped values */
/* Fill skipped values (all positions up to rankVal[minWeight]).
* These are positions only get a single symbol because the combined weight
* is too large.
*/
if (minWeight>1) {
U32 i, skipSize = rankVal[minWeight];
MEM_writeLE16(&(DElt.sequence), baseSeq);
DElt.nbBits = (BYTE)(consumed);
DElt.length = 1;
for (i = 0; i < skipSize; i++)
DTable[i] = DElt;
U32 const length = 1U << ((targetLog - consumedBits) & 0x1F /* quiet static-analyzer */);
U64 const DEltX2 = HUF_buildDEltX2U64(baseSeq, consumedBits, /* baseSeq */ 0, /* level */ 1);
int const skipSize = rankVal[minWeight];
assert(length > 1);
assert((U32)skipSize < length);
switch (length) {
case 2:
assert(skipSize == 1);
ZSTD_memcpy(DTable, &DEltX2, sizeof(DEltX2));
break;
case 4:
assert(skipSize <= 4);
ZSTD_memcpy(DTable + 0, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTable + 2, &DEltX2, sizeof(DEltX2));
break;
default:
{
int i;
for (i = 0; i < skipSize; i += 8) {
ZSTD_memcpy(DTable + i + 0, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTable + i + 2, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTable + i + 4, &DEltX2, sizeof(DEltX2));
ZSTD_memcpy(DTable + i + 6, &DEltX2, sizeof(DEltX2));
}
}
}
}
/* fill DTable */
{ U32 s; for (s=0; s<sortedListSize; s++) { /* note : sortedSymbols already skipped */
const U32 symbol = sortedSymbols[s].symbol;
const U32 weight = sortedSymbols[s].weight;
const U32 nbBits = nbBitsBaseline - weight;
const U32 length = 1 << (sizeLog-nbBits);
const U32 start = rankVal[weight];
U32 i = start;
const U32 end = start + length;
MEM_writeLE16(&(DElt.sequence), (U16)(baseSeq + (symbol << 8)));
DElt.nbBits = (BYTE)(nbBits + consumed);
DElt.length = 2;
do { DTable[i++] = DElt; } while (i<end); /* since length >= 1 */
rankVal[weight] += length;
} }
/* Fill each of the second level symbols by weight. */
{
int w;
for (w = minWeight; w < maxWeight1; ++w) {
int const begin = rankStart[w];
int const end = rankStart[w+1];
U32 const nbBits = nbBitsBaseline - w;
U32 const totalBits = nbBits + consumedBits;
HUF_fillDTableX2ForWeight(
DTable + rankVal[w],
sortedSymbols + begin, sortedSymbols + end,
totalBits, targetLog,
baseSeq, /* level */ 2);
}
}
}
static void HUF_fillDTableX2(HUF_DEltX2* DTable, const U32 targetLog,
const sortedSymbol_t* sortedList, const U32 sortedListSize,
const sortedSymbol_t* sortedList,
const U32* rankStart, rankVal_t rankValOrigin, const U32 maxWeight,
const U32 nbBitsBaseline, U32* wksp, size_t wkspSize)
const U32 nbBitsBaseline)
{
U32* rankVal = wksp;
U32* const rankVal = rankValOrigin[0];
const int scaleLog = nbBitsBaseline - targetLog; /* note : targetLog >= srcLog, hence scaleLog <= 1 */
const U32 minBits = nbBitsBaseline - maxWeight;
U32 s;
int w;
int const wEnd = (int)maxWeight + 1;
assert(wkspSize >= HUF_TABLELOG_MAX + 1);
wksp += HUF_TABLELOG_MAX + 1;
wkspSize -= HUF_TABLELOG_MAX + 1;
/* Fill DTable in order of weight. */
for (w = 1; w < wEnd; ++w) {
int const begin = (int)rankStart[w];
int const end = (int)rankStart[w+1];
U32 const nbBits = nbBitsBaseline - w;
ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1));
/* fill DTable */
for (s=0; s<sortedListSize; s++) {
const U16 symbol = sortedList[s].symbol;
const U32 weight = sortedList[s].weight;
const U32 nbBits = nbBitsBaseline - weight;
const U32 start = rankVal[weight];
const U32 length = 1 << (targetLog-nbBits);
if (targetLog-nbBits >= minBits) { /* enough room for a second symbol */
U32 sortedRank;
if (targetLog-nbBits >= minBits) {
/* Enough room for a second symbol. */
int start = rankVal[w];
U32 const length = 1U << ((targetLog - nbBits) & 0x1F /* quiet static-analyzer */);
int minWeight = nbBits + scaleLog;
int s;
if (minWeight < 1) minWeight = 1;
sortedRank = rankStart[minWeight];
HUF_fillDTableX2Level2(DTable+start, targetLog-nbBits, nbBits,
rankValOrigin[nbBits], minWeight,
sortedList+sortedRank, sortedListSize-sortedRank,
nbBitsBaseline, symbol, wksp, wkspSize);
/* Fill the DTable for every symbol of weight w.
* These symbols get at least 1 second symbol.
*/
for (s = begin; s != end; ++s) {
HUF_fillDTableX2Level2(
DTable + start, targetLog, nbBits,
rankValOrigin[nbBits], minWeight, wEnd,
sortedList, rankStart,
nbBitsBaseline, sortedList[s].symbol);
start += length;
}
} else {
HUF_DEltX2 DElt;
MEM_writeLE16(&(DElt.sequence), symbol);
DElt.nbBits = (BYTE)(nbBits);
DElt.length = 1;
{ U32 const end = start + length;
U32 u;
for (u = start; u < end; u++) DTable[u] = DElt;
} }
rankVal[weight] += length;
/* Only a single symbol. */
HUF_fillDTableX2ForWeight(
DTable + rankVal[w],
sortedList + begin, sortedList + end,
nbBits, targetLog,
/* baseSeq */ 0, /* level */ 1);
}
}
}
typedef struct {
rankValCol_t rankVal[HUF_TABLELOG_MAX];
U32 rankStats[HUF_TABLELOG_MAX + 1];
U32 rankStart0[HUF_TABLELOG_MAX + 2];
U32 rankStart0[HUF_TABLELOG_MAX + 3];
sortedSymbol_t sortedSymbol[HUF_SYMBOLVALUE_MAX + 1];
BYTE weightList[HUF_SYMBOLVALUE_MAX + 1];
U32 calleeWksp[HUF_READ_STATS_WORKSPACE_SIZE_U32];
@@ -632,9 +1051,16 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
const void* src, size_t srcSize,
void* workSpace, size_t wkspSize)
{
U32 tableLog, maxW, sizeOfSort, nbSymbols;
return HUF_readDTableX2_wksp_bmi2(DTable, src, srcSize, workSpace, wkspSize, /* bmi2 */ 0);
}
size_t HUF_readDTableX2_wksp_bmi2(HUF_DTable* DTable,
const void* src, size_t srcSize,
void* workSpace, size_t wkspSize, int bmi2)
{
U32 tableLog, maxW, nbSymbols;
DTableDesc dtd = HUF_getDTableDesc(DTable);
U32 const maxTableLog = dtd.maxTableLog;
U32 maxTableLog = dtd.maxTableLog;
size_t iSize;
void* dtPtr = DTable+1; /* force compiler to avoid strict-aliasing */
HUF_DEltX2* const dt = (HUF_DEltX2*)dtPtr;
@@ -652,11 +1078,12 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
if (maxTableLog > HUF_TABLELOG_MAX) return ERROR(tableLog_tooLarge);
/* ZSTD_memset(weightList, 0, sizeof(weightList)); */ /* is not necessary, even though some analyzer complain ... */
iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), /* bmi2 */ 0);
iSize = HUF_readStats_wksp(wksp->weightList, HUF_SYMBOLVALUE_MAX + 1, wksp->rankStats, &nbSymbols, &tableLog, src, srcSize, wksp->calleeWksp, sizeof(wksp->calleeWksp), bmi2);
if (HUF_isError(iSize)) return iSize;
/* check result */
if (tableLog > maxTableLog) return ERROR(tableLog_tooLarge); /* DTable can't fit code depth */
if (tableLog <= HUF_DECODER_FAST_TABLELOG && maxTableLog > HUF_DECODER_FAST_TABLELOG) maxTableLog = HUF_DECODER_FAST_TABLELOG;
/* find maxWeight */
for (maxW = tableLog; wksp->rankStats[maxW]==0; maxW--) {} /* necessarily finds a solution before 0 */
@@ -669,7 +1096,7 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
rankStart[w] = curr;
}
rankStart[0] = nextRankStart; /* put all 0w symbols at the end of sorted list*/
sizeOfSort = nextRankStart;
rankStart[maxW+1] = nextRankStart;
}
/* sort symbols by weight */
@@ -678,7 +1105,6 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
U32 const w = wksp->weightList[s];
U32 const r = rankStart[w]++;
wksp->sortedSymbol[r].symbol = (BYTE)s;
wksp->sortedSymbol[r].weight = (BYTE)w;
}
rankStart[0] = 0; /* forget 0w symbols; this is beginning of weight(1) */
}
@@ -703,10 +1129,9 @@ size_t HUF_readDTableX2_wksp(HUF_DTable* DTable,
} } } }
HUF_fillDTableX2(dt, maxTableLog,
wksp->sortedSymbol, sizeOfSort,
wksp->sortedSymbol,
wksp->rankStart0, wksp->rankVal, maxW,
tableLog+1,
wksp->calleeWksp, sizeof(wksp->calleeWksp) / sizeof(U32));
tableLog+1);
dtd.tableLog = (BYTE)maxTableLog;
dtd.tableType = 1;
@@ -719,7 +1144,7 @@ FORCE_INLINE_TEMPLATE U32
HUF_decodeSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
{
size_t const val = BIT_lookBitsFast(DStream, dtLog); /* note : dtLog >= 1 */
ZSTD_memcpy(op, dt+val, 2);
ZSTD_memcpy(op, &dt[val].sequence, 2);
BIT_skipBits(DStream, dt[val].nbBits);
return dt[val].length;
}
@@ -728,15 +1153,17 @@ FORCE_INLINE_TEMPLATE U32
HUF_decodeLastSymbolX2(void* op, BIT_DStream_t* DStream, const HUF_DEltX2* dt, const U32 dtLog)
{
size_t const val = BIT_lookBitsFast(DStream, dtLog); /* note : dtLog >= 1 */
ZSTD_memcpy(op, dt+val, 1);
if (dt[val].length==1) BIT_skipBits(DStream, dt[val].nbBits);
else {
ZSTD_memcpy(op, &dt[val].sequence, 1);
if (dt[val].length==1) {
BIT_skipBits(DStream, dt[val].nbBits);
} else {
if (DStream->bitsConsumed < (sizeof(DStream->bitContainer)*8)) {
BIT_skipBits(DStream, dt[val].nbBits);
if (DStream->bitsConsumed > (sizeof(DStream->bitContainer)*8))
/* ugly hack; works only because it's the last symbol. Note : can't easily extract nbBits from just this symbol */
DStream->bitsConsumed = (sizeof(DStream->bitContainer)*8);
} }
}
}
return 1;
}
@@ -759,11 +1186,23 @@ HUF_decodeStreamX2(BYTE* p, BIT_DStream_t* bitDPtr, BYTE* const pEnd,
/* up to 8 symbols at a time */
if ((size_t)(pEnd - p) >= sizeof(bitDPtr->bitContainer)) {
while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) {
HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
if (dtLog <= 11 && MEM_64bits()) {
/* up to 10 symbols at a time */
while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-9)) {
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
}
} else {
/* up to 8 symbols at a time */
while ((BIT_reloadDStream(bitDPtr) == BIT_DStream_unfinished) & (p < pEnd-(sizeof(bitDPtr->bitContainer)-1))) {
HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
HUF_DECODE_SYMBOLX2_1(p, bitDPtr);
HUF_DECODE_SYMBOLX2_2(p, bitDPtr);
HUF_DECODE_SYMBOLX2_0(p, bitDPtr);
}
}
}
@@ -808,7 +1247,6 @@ HUF_decompress1X2_usingDTable_internal_body(
/* decoded size */
return dstSize;
}
FORCE_INLINE_TEMPLATE size_t
HUF_decompress4X2_usingDTable_internal_body(
void* dst, size_t dstSize,
@@ -927,8 +1365,97 @@ HUF_decompress4X2_usingDTable_internal_body(
}
}
#if DYNAMIC_BMI2
static TARGET_ATTRIBUTE("bmi2")
size_t HUF_decompress4X2_usingDTable_internal_bmi2(void* dst, size_t dstSize, void const* cSrc,
size_t cSrcSize, HUF_DTable const* DTable) {
return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}
#endif
static
size_t HUF_decompress4X2_usingDTable_internal_default(void* dst, size_t dstSize, void const* cSrc,
size_t cSrcSize, HUF_DTable const* DTable) {
return HUF_decompress4X2_usingDTable_internal_body(dst, dstSize, cSrc, cSrcSize, DTable);
}
#if HUF_ENABLE_ASM_X86_64_BMI2
HUF_ASM_DECL void HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop(HUF_DecompressAsmArgs* args);
static HUF_ASM_X86_64_BMI2_ATTRS size_t
HUF_decompress4X2_usingDTable_internal_bmi2_asm(
void* dst, size_t dstSize,
const void* cSrc, size_t cSrcSize,
const HUF_DTable* DTable) {
void const* dt = DTable + 1;
const BYTE* const iend = (const BYTE*)cSrc + 6;
BYTE* const oend = (BYTE*)dst + dstSize;
HUF_DecompressAsmArgs args;
{
size_t const ret = HUF_DecompressAsmArgs_init(&args, dst, dstSize, cSrc, cSrcSize, DTable);
FORWARD_IF_ERROR(ret, "Failed to init asm args");
if (ret != 0)
return HUF_decompress4X2_usingDTable_internal_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);
}
assert(args.ip[0] >= args.ilimit);
HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop(&args);
/* note : op4 already verified within main loop */
assert(args.ip[0] >= iend);
assert(args.ip[1] >= iend);
assert(args.ip[2] >= iend);
assert(args.ip[3] >= iend);
assert(args.op[3] <= oend);
(void)iend;
/* finish bitStreams one by one */
{
size_t const segmentSize = (dstSize+3) / 4;
BYTE* segmentEnd = (BYTE*)dst;
int i;
for (i = 0; i < 4; ++i) {
BIT_DStream_t bit;
if (segmentSize <= (size_t)(oend - segmentEnd))
segmentEnd += segmentSize;
else
segmentEnd = oend;
FORWARD_IF_ERROR(HUF_initRemainingDStream(&bit, &args, i, segmentEnd), "corruption");
args.op[i] += HUF_decodeStreamX2(args.op[i], &bit, segmentEnd, (HUF_DEltX2 const*)dt, HUF_DECODER_FAST_TABLELOG);
if (args.op[i] != segmentEnd)
return ERROR(corruption_detected);
}
}
/* decoded size */
return dstSize;
}
#endif /* HUF_ENABLE_ASM_X86_64_BMI2 */
static size_t HUF_decompress4X2_usingDTable_internal(void* dst, size_t dstSize, void const* cSrc,
size_t cSrcSize, HUF_DTable const* DTable, int bmi2)
{
#if DYNAMIC_BMI2
if (bmi2) {
# if HUF_ENABLE_ASM_X86_64_BMI2
return HUF_decompress4X2_usingDTable_internal_bmi2_asm(dst, dstSize, cSrc, cSrcSize, DTable);
# else
return HUF_decompress4X2_usingDTable_internal_bmi2(dst, dstSize, cSrc, cSrcSize, DTable);
# endif
}
#else
(void)bmi2;
#endif
#if HUF_ENABLE_ASM_X86_64_BMI2 && defined(__BMI2__)
return HUF_decompress4X2_usingDTable_internal_bmi2_asm(dst, dstSize, cSrc, cSrcSize, DTable);
#else
return HUF_decompress4X2_usingDTable_internal_default(dst, dstSize, cSrc, cSrcSize, DTable);
#endif
}
HUF_DGEN(HUF_decompress1X2_usingDTable_internal)
HUF_DGEN(HUF_decompress4X2_usingDTable_internal)
size_t HUF_decompress1X2_usingDTable(
void* dst, size_t dstSize,
@@ -1037,25 +1564,25 @@ size_t HUF_decompress4X_usingDTable(void* dst, size_t maxDstSize,
#if !defined(HUF_FORCE_DECOMPRESS_X1) && !defined(HUF_FORCE_DECOMPRESS_X2)
typedef struct { U32 tableTime; U32 decode256Time; } algo_time_t;
static const algo_time_t algoTime[16 /* Quantization */][3 /* single, double, quad */] =
static const algo_time_t algoTime[16 /* Quantization */][2 /* single, double */] =
{
/* single, double, quad */
{{0,0}, {1,1}, {2,2}}, /* Q==0 : impossible */
{{0,0}, {1,1}, {2,2}}, /* Q==1 : impossible */
{{ 38,130}, {1313, 74}, {2151, 38}}, /* Q == 2 : 12-18% */
{{ 448,128}, {1353, 74}, {2238, 41}}, /* Q == 3 : 18-25% */
{{ 556,128}, {1353, 74}, {2238, 47}}, /* Q == 4 : 25-32% */
{{ 714,128}, {1418, 74}, {2436, 53}}, /* Q == 5 : 32-38% */
{{ 883,128}, {1437, 74}, {2464, 61}}, /* Q == 6 : 38-44% */
{{ 897,128}, {1515, 75}, {2622, 68}}, /* Q == 7 : 44-50% */
{{ 926,128}, {1613, 75}, {2730, 75}}, /* Q == 8 : 50-56% */
{{ 947,128}, {1729, 77}, {3359, 77}}, /* Q == 9 : 56-62% */
{{1107,128}, {2083, 81}, {4006, 84}}, /* Q ==10 : 62-69% */
{{1177,128}, {2379, 87}, {4785, 88}}, /* Q ==11 : 69-75% */
{{1242,128}, {2415, 93}, {5155, 84}}, /* Q ==12 : 75-81% */
{{1349,128}, {2644,106}, {5260,106}}, /* Q ==13 : 81-87% */
{{1455,128}, {2422,124}, {4174,124}}, /* Q ==14 : 87-93% */
{{ 722,128}, {1891,145}, {1936,146}}, /* Q ==15 : 93-99% */
{{0,0}, {1,1}}, /* Q==0 : impossible */
{{0,0}, {1,1}}, /* Q==1 : impossible */
{{ 150,216}, { 381,119}}, /* Q == 2 : 12-18% */
{{ 170,205}, { 514,112}}, /* Q == 3 : 18-25% */
{{ 177,199}, { 539,110}}, /* Q == 4 : 25-32% */
{{ 197,194}, { 644,107}}, /* Q == 5 : 32-38% */
{{ 221,192}, { 735,107}}, /* Q == 6 : 38-44% */
{{ 256,189}, { 881,106}}, /* Q == 7 : 44-50% */
{{ 359,188}, {1167,109}}, /* Q == 8 : 50-56% */
{{ 582,187}, {1570,114}}, /* Q == 9 : 56-62% */
{{ 688,187}, {1712,122}}, /* Q ==10 : 62-69% */
{{ 825,186}, {1965,136}}, /* Q ==11 : 69-75% */
{{ 976,185}, {2131,150}}, /* Q ==12 : 75-81% */
{{1180,186}, {2070,175}}, /* Q ==13 : 81-87% */
{{1377,185}, {1731,202}}, /* Q ==14 : 87-93% */
{{1412,185}, {1695,202}}, /* Q ==15 : 93-99% */
};
#endif
@@ -1082,7 +1609,7 @@ U32 HUF_selectDecoder (size_t dstSize, size_t cSrcSize)
U32 const D256 = (U32)(dstSize >> 8);
U32 const DTime0 = algoTime[Q][0].tableTime + (algoTime[Q][0].decode256Time * D256);
U32 DTime1 = algoTime[Q][1].tableTime + (algoTime[Q][1].decode256Time * D256);
DTime1 += DTime1 >> 3; /* advantage to algorithm using less memory, to reduce cache eviction */
DTime1 += DTime1 >> 5; /* small advantage to algorithm using less memory, to reduce cache eviction */
return DTime1 < DTime0;
}
#endif