#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
#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
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
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];
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;
}
}
+#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,
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(
/* *************************/
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;
+ }
+}
-/* 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)
+/**
+ * Constructs a HUF_DEltX2.
+ */
+static HUF_DEltX2 HUF_buildDEltX2(U32 symbol, U32 nbBits, U32 baseSeq, int level)
{
HUF_DEltX2 DElt;
- U32* rankVal = wksp;
+ U32 const val = HUF_buildDEltX2U32(symbol, nbBits, baseSeq, level);
+ DEBUG_STATIC_ASSERT(sizeof(DElt) == sizeof(val));
+ ZSTD_memcpy(&DElt, &val, sizeof(val));
+ return DElt;
+}
- assert(wkspSize >= HUF_TABLELOG_MAX + 1);
- (void)wkspSize;
- /* get pre-calculated rankVal */
- ZSTD_memcpy(rankVal, rankValOrigin, sizeof(U32) * (HUF_TABLELOG_MAX + 1));
+/**
+ * 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);
+}
- /* fill skipped values */
- 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;
+/**
+ * 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;
}
+}
- /* 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 */
+/* HUF_fillDTableX2Level2() :
+ * `rankValOrigin` must be a table of at least (HUF_TABLELOG_MAX + 1) U32 */
+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)
+{
+ /* 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 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));
+ }
+ }
+ }
+ }
- 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;
-
- assert(wkspSize >= HUF_TABLELOG_MAX + 1);
- wksp += HUF_TABLELOG_MAX + 1;
- wkspSize -= HUF_TABLELOG_MAX + 1;
-
- 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;
+ int w;
+ int const wEnd = (int)maxWeight + 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;
+
+ 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];
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;
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 */
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 */
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) */
}
} } } }
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;
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;
}
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;
}
/* 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);
+ }
}
}
/* decoded size */
return dstSize;
}
-
FORCE_INLINE_TEMPLATE size_t
HUF_decompress4X2_usingDTable_internal_body(
void* dst, size_t dstSize,
}
}
+#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,
#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
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
--- /dev/null
+# Calling convention:
+#
+# %rdi contains the first argument: HUF_DecompressAsmArgs*.
+# %rbp is'nt maintained (no frame pointer).
+# %rsp contains the stack pointer that grows down.
+# No red-zone is assumed, only addresses >= %rsp are used.
+# All register contents are preserved.
+#
+# TODO: Support Windows calling convention.
+
+#if !defined(HUF_DISABLE_ASM) && defined(__x86_64__)
+.global HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop
+.global HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop
+.global _HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop
+.global _HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop
+.text
+
+# Sets up register mappings for clarity.
+# op[], bits[], dtable & ip[0] each get their own register.
+# ip[1,2,3] & olimit alias var[].
+# %rax is a scratch register.
+
+#define op0 rsi
+#define op1 rbx
+#define op2 rcx
+#define op3 rdi
+
+#define ip0 r8
+#define ip1 r9
+#define ip2 r10
+#define ip3 r11
+
+#define bits0 rbp
+#define bits1 rdx
+#define bits2 r12
+#define bits3 r13
+#define dtable r14
+#define olimit r15
+
+# var[] aliases ip[1,2,3] & olimit
+# ip[1,2,3] are saved every iteration.
+# olimit is only used in compute_olimit.
+#define var0 r15
+#define var1 r9
+#define var2 r10
+#define var3 r11
+
+# 32-bit var registers
+#define vard0 r15d
+#define vard1 r9d
+#define vard2 r10d
+#define vard3 r11d
+
+# Helper macro: args if idx != 4.
+#define IF_NOT_4_0(...) __VA_ARGS__
+#define IF_NOT_4_1(...) __VA_ARGS__
+#define IF_NOT_4_2(...) __VA_ARGS__
+#define IF_NOT_4_3(...) __VA_ARGS__
+#define IF_NOT_4_4(...)
+#define IF_NOT_4_(idx, ...) IF_NOT_4_##idx(__VA_ARGS__)
+#define IF_NOT_4(idx, ...) IF_NOT_4_(idx, __VA_ARGS__)
+
+# Calls X(N) for each stream 0, 1, 2, 3.
+#define FOR_EACH_STREAM(X) \
+ X(0); \
+ X(1); \
+ X(2); \
+ X(3)
+
+# Calls X(N, idx) for each stream 0, 1, 2, 3.
+#define FOR_EACH_STREAM_WITH_INDEX(X, idx) \
+ X(0, idx); \
+ X(1, idx); \
+ X(2, idx); \
+ X(3, idx)
+
+# Define both _HUF_* & HUF_* symbols because MacOS
+# C symbols are prefixed with '_' & Linux symbols aren't.
+_HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop:
+HUF_decompress4X1_usingDTable_internal_bmi2_asm_loop:
+ # Save all registers - even if they are callee saved for simplicity.
+ push %rax
+ push %rbx
+ push %rcx
+ push %rdx
+ push %rbp
+ push %rsi
+ push %rdi
+ push %r8
+ push %r9
+ push %r10
+ push %r11
+ push %r12
+ push %r13
+ push %r14
+ push %r15
+
+ # Read HUF_DecompressAsmArgs* args from %rax
+ movq %rdi, %rax
+ movq 0(%rax), %ip0
+ movq 8(%rax), %ip1
+ movq 16(%rax), %ip2
+ movq 24(%rax), %ip3
+ movq 32(%rax), %op0
+ movq 40(%rax), %op1
+ movq 48(%rax), %op2
+ movq 56(%rax), %op3
+ movq 64(%rax), %bits0
+ movq 72(%rax), %bits1
+ movq 80(%rax), %bits2
+ movq 88(%rax), %bits3
+ movq 96(%rax), %dtable
+ push %rax # argument
+ push 104(%rax) # ilimit
+ push 112(%rax) # oend
+ push %olimit # olimit space
+
+ subq $24, %rsp
+
+.L_4X1_compute_olimit:
+ # Computes how many iterations we can do savely
+ # %r15, %rax may be clobbered
+ # rbx, rdx must be saved
+ # op3 & ip0 mustn't be clobbered
+ movq %rbx, 0(%rsp)
+ movq %rdx, 8(%rsp)
+
+ movq 32(%rsp), %rax # rax = oend
+ subq %op3, %rax # rax = oend - op3
+
+ # r15 = (oend - op3) / 5
+ movabsq $-3689348814741910323, %rdx
+ mulq %rdx
+ movq %rdx, %r15
+ shrq $2, %r15
+
+ movq %ip0, %rax # rax = ip0
+ movq 40(%rsp), %rdx # rdx = ilimit
+ subq %rdx, %rax # rax = ip0 - ilimit
+ movq %rax, %rbx # rbx = ip0 - ilimit
+
+ # rdx = (ip0 - ilimit) / 7
+ movabsq $2635249153387078803, %rdx
+ mulq %rdx
+ subq %rdx, %rbx
+ shrq %rbx
+ addq %rbx, %rdx
+ shrq $2, %rdx
+
+ # r15 = min(%rdx, %r15)
+ cmpq %rdx, %r15
+ cmova %rdx, %r15
+
+ # r15 = r15 * 5
+ leaq (%r15, %r15, 4), %r15
+
+ # olimit = op3 + r15
+ addq %op3, %olimit
+
+ movq 8(%rsp), %rdx
+ movq 0(%rsp), %rbx
+
+ # If (op3 + 20 > olimit)
+ movq %op3, %rax # rax = op3
+ addq $20, %rax # rax = op3 + 20
+ cmpq %rax, %olimit # op3 + 20 > olimit
+ jb .L_4X1_exit
+
+ # If (ip1 < ip0) go to exit
+ cmpq %ip0, %ip1
+ jb .L_4X1_exit
+
+ # If (ip2 < ip1) go to exit
+ cmpq %ip1, %ip2
+ jb .L_4X1_exit
+
+ # If (ip3 < ip2) go to exit
+ cmpq %ip2, %ip3
+ jb .L_4X1_exit
+
+# Reads top 11 bits from bits[n]
+# Loads dt[bits[n]] into var[n]
+#define GET_NEXT_DELT(n) \
+ movq $53, %var##n; \
+ shrxq %var##n, %bits##n, %var##n; \
+ movzwl (%dtable,%var##n,2),%vard##n
+
+# var[n] must contain the DTable entry computed with GET_NEXT_DELT
+# Moves var[n] to %rax
+# bits[n] <<= var[n] & 63
+# op[n][idx] = %rax >> 8
+# %ah is a way to access bits [8, 16) of %rax
+#define DECODE_FROM_DELT(n, idx) \
+ movq %var##n, %rax; \
+ shlxq %var##n, %bits##n, %bits##n; \
+ movb %ah, idx(%op##n)
+
+# Assumes GET_NEXT_DELT has been called.
+# Calls DECODE_FROM_DELT then GET_NEXT_DELT if n < 4
+#define DECODE(n, idx) \
+ DECODE_FROM_DELT(n, idx); \
+ IF_NOT_4(idx, GET_NEXT_DELT(n))
+
+# // ctz & nbBytes is stored in bits[n]
+# // nbBits is stored in %rax
+# ctz = CTZ[bits[n]]
+# nbBits = ctz & 7
+# nbBytes = ctz >> 3
+# op[n] += 5
+# ip[n] -= nbBytes
+# // Note: x86-64 is little-endian ==> no bswap
+# bits[n] = MEM_readST(ip[n]) | 1
+# bits[n] <<= nbBits
+#define RELOAD_BITS(n) \
+ bsfq %bits##n, %bits##n; \
+ movq %bits##n, %rax; \
+ andq $7, %rax; \
+ shrq $3, %bits##n; \
+ leaq 5(%op##n), %op##n; \
+ subq %bits##n, %ip##n; \
+ movq (%ip##n), %bits##n; \
+ orq $1, %bits##n; \
+ shlx %rax, %bits##n, %bits##n;
+
+ # Store clobbered variables on the stack
+ movq %olimit, 24(%rsp)
+ movq %ip1, 0(%rsp)
+ movq %ip2, 8(%rsp)
+ movq %ip3, 16(%rsp)
+
+ # Call GET_NEXT_DELT for each stream
+ FOR_EACH_STREAM(GET_NEXT_DELT)
+
+ .p2align 6
+
+.L_4X1_loop_body:
+# LLVM-MCA-BEGIN decode-4X1
+ # Decode 5 symbols in each of the 4 streams (20 total)
+ # Must have called GET_NEXT_DELT for each stream
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 0)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 1)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 2)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 3)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 4)
+
+ # Load ip[1,2,3] from stack (var[] aliases them)
+ # ip[] is needed for RELOAD_BITS
+ # Each will be stored back to the stack after RELOAD
+ movq 0(%rsp), %ip1
+ movq 8(%rsp), %ip2
+ movq 16(%rsp), %ip3
+
+ # Reload each stream & fetch the next table entry
+ # to prepare for the next iteration
+ RELOAD_BITS(0)
+ GET_NEXT_DELT(0)
+
+ RELOAD_BITS(1)
+ movq %ip1, 0(%rsp)
+ GET_NEXT_DELT(1)
+
+ RELOAD_BITS(2)
+ movq %ip2, 8(%rsp)
+ GET_NEXT_DELT(2)
+
+ RELOAD_BITS(3)
+ movq %ip3, 16(%rsp)
+ GET_NEXT_DELT(3)
+
+ # If op3 < olimit: continue the loop
+ cmp %op3, 24(%rsp)
+ ja .L_4X1_loop_body
+
+ # Reload ip[1,2,3] from stack
+ movq 0(%rsp), %ip1
+ movq 8(%rsp), %ip2
+ movq 16(%rsp), %ip3
+
+ # Re-compute olimit
+ jmp .L_4X1_compute_olimit
+
+#undef GET_NEXT_DELT
+#undef DECODE_FROM_DELT
+#undef DECODE
+#undef RELOAD_BITS
+# LLVM-MCA-END
+.L_4X1_exit:
+ addq $24, %rsp
+
+ # Restore stack (oend & olimit)
+ pop %rax # olimit
+ pop %rax # oend
+ pop %rax # ilimit
+ pop %rax # arg
+
+ # Save ip / op / bits
+ movq %ip0, 0(%rax)
+ movq %ip1, 8(%rax)
+ movq %ip2, 16(%rax)
+ movq %ip3, 24(%rax)
+ movq %op0, 32(%rax)
+ movq %op1, 40(%rax)
+ movq %op2, 48(%rax)
+ movq %op3, 56(%rax)
+ movq %bits0, 64(%rax)
+ movq %bits1, 72(%rax)
+ movq %bits2, 80(%rax)
+ movq %bits3, 88(%rax)
+
+ # Restore registers
+ pop %r15
+ pop %r14
+ pop %r13
+ pop %r12
+ pop %r11
+ pop %r10
+ pop %r9
+ pop %r8
+ pop %rdi
+ pop %rsi
+ pop %rbp
+ pop %rdx
+ pop %rcx
+ pop %rbx
+ pop %rax
+ ret
+
+_HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop:
+HUF_decompress4X2_usingDTable_internal_bmi2_asm_loop:
+ # Save all registers - even if they are callee saved for simplicity.
+ push %rax
+ push %rbx
+ push %rcx
+ push %rdx
+ push %rbp
+ push %rsi
+ push %rdi
+ push %r8
+ push %r9
+ push %r10
+ push %r11
+ push %r12
+ push %r13
+ push %r14
+ push %r15
+
+ movq %rdi, %rax
+ movq 0(%rax), %ip0
+ movq 8(%rax), %ip1
+ movq 16(%rax), %ip2
+ movq 24(%rax), %ip3
+ movq 32(%rax), %op0
+ movq 40(%rax), %op1
+ movq 48(%rax), %op2
+ movq 56(%rax), %op3
+ movq 64(%rax), %bits0
+ movq 72(%rax), %bits1
+ movq 80(%rax), %bits2
+ movq 88(%rax), %bits3
+ movq 96(%rax), %dtable
+ push %rax # argument
+ push %rax # olimit
+ push 104(%rax) # ilimit
+
+ movq 112(%rax), %rax
+ push %rax # oend3
+
+ movq %op3, %rax
+ push %rax # oend2
+
+ movq %op2, %rax
+ push %rax # oend1
+
+ movq %op1, %rax
+ push %rax # oend0
+
+ # Scratch space
+ subq $8, %rsp
+
+.L_4X2_compute_olimit:
+ # Computes how many iterations we can do savely
+ # %r15, %rax may be clobbered
+ # rdx must be saved
+ # op[1,2,3,4] & ip0 mustn't be clobbered
+ movq %rdx, 0(%rsp)
+
+ # We can consume up to 7 input bytes each iteration.
+ movq %ip0, %rax # rax = ip0
+ movq 40(%rsp), %rdx # rdx = ilimit
+ subq %rdx, %rax # rax = ip0 - ilimit
+ movq %rax, %r15 # r15 = ip0 - ilimit
+
+ # rdx = rax / 7
+ movabsq $2635249153387078803, %rdx
+ mulq %rdx
+ subq %rdx, %r15
+ shrq %r15
+ addq %r15, %rdx
+ shrq $2, %rdx
+
+ # r15 = (ip0 - ilimit) / 7
+ movq %rdx, %r15
+
+ movabsq $-3689348814741910323, %rdx
+ movq 8(%rsp), %rax # rax = oend0
+ subq %op0, %rax # rax = oend0 - op0
+ mulq %rdx
+ shrq $3, %rdx # rdx = rax / 10
+
+ # r15 = min(%rdx, %r15)
+ cmpq %rdx, %r15
+ cmova %rdx, %r15
+
+ movabsq $-3689348814741910323, %rdx
+ movq 16(%rsp), %rax # rax = oend1
+ subq %op1, %rax # rax = oend1 - op1
+ mulq %rdx
+ shrq $3, %rdx # rdx = rax / 10
+
+ # r15 = min(%rdx, %r15)
+ cmpq %rdx, %r15
+ cmova %rdx, %r15
+
+ movabsq $-3689348814741910323, %rdx
+ movq 24(%rsp), %rax # rax = oend2
+ subq %op2, %rax # rax = oend2 - op2
+ mulq %rdx
+ shrq $3, %rdx # rdx = rax / 10
+
+ # r15 = min(%rdx, %r15)
+ cmpq %rdx, %r15
+ cmova %rdx, %r15
+
+ movabsq $-3689348814741910323, %rdx
+ movq 32(%rsp), %rax # rax = oend3
+ subq %op3, %rax # rax = oend3 - op3
+ mulq %rdx
+ shrq $3, %rdx # rdx = rax / 10
+
+ # r15 = min(%rdx, %r15)
+ cmpq %rdx, %r15
+ cmova %rdx, %r15
+
+ # olimit = op3 + 5 * r15
+ movq %r15, %rax
+ leaq (%op3, %rax, 4), %olimit
+ addq %rax, %olimit
+
+ movq 0(%rsp), %rdx
+
+ # If (op3 + 10 > olimit)
+ movq %op3, %rax # rax = op3
+ addq $10, %rax # rax = op3 + 10
+ cmpq %rax, %olimit # op3 + 10 > olimit
+ jb .L_4X2_exit
+
+ # If (ip1 < ip0) go to exit
+ cmpq %ip0, %ip1
+ jb .L_4X2_exit
+
+ # If (ip2 < ip1) go to exit
+ cmpq %ip1, %ip2
+ jb .L_4X2_exit
+
+ # If (ip3 < ip2) go to exit
+ cmpq %ip2, %ip3
+ jb .L_4X2_exit
+
+#define DECODE(n, idx) \
+ movq %bits##n, %rax; \
+ shrq $53, %rax; \
+ movzwl 0(%dtable,%rax,4),%r8d; \
+ movzbl 2(%dtable,%rax,4),%r15d; \
+ movzbl 3(%dtable,%rax,4),%eax; \
+ movw %r8w, (%op##n); \
+ shlxq %r15, %bits##n, %bits##n; \
+ addq %rax, %op##n
+
+#define RELOAD_BITS(n) \
+ bsfq %bits##n, %bits##n; \
+ movq %bits##n, %rax; \
+ shrq $3, %bits##n; \
+ andq $7, %rax; \
+ subq %bits##n, %ip##n; \
+ movq (%ip##n), %bits##n; \
+ orq $1, %bits##n; \
+ shlxq %rax, %bits##n, %bits##n;
+
+
+ movq %olimit, 48(%rsp)
+
+ .p2align 6
+
+.L_4X2_loop_body:
+# LLVM-MCA-BEGIN decode-4X2
+
+ # We clobber r8, so store it on the stack
+ movq %r8, 0(%rsp)
+
+ # Decode 5 symbols from each of the 4 streams (20 symbols total).
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 0)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 1)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 2)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 3)
+ FOR_EACH_STREAM_WITH_INDEX(DECODE, 4)
+
+ # Reload r8
+ movq 0(%rsp), %r8
+
+ FOR_EACH_STREAM(RELOAD_BITS)
+
+ cmp %op3, 48(%rsp)
+ ja .L_4X2_loop_body
+ jmp .L_4X2_compute_olimit
+
+#undef DECODE
+#undef RELOAD_BITS
+# LLVM-MCA-END
+.L_4X2_exit:
+ addq $8, %rsp
+ # Restore stack (oend & olimit)
+ pop %rax # oend0
+ pop %rax # oend1
+ pop %rax # oend2
+ pop %rax # oend3
+ pop %rax # ilimit
+ pop %rax # olimit
+ pop %rax # arg
+
+ # Save ip / op / bits
+ movq %ip0, 0(%rax)
+ movq %ip1, 8(%rax)
+ movq %ip2, 16(%rax)
+ movq %ip3, 24(%rax)
+ movq %op0, 32(%rax)
+ movq %op1, 40(%rax)
+ movq %op2, 48(%rax)
+ movq %op3, 56(%rax)
+ movq %bits0, 64(%rax)
+ movq %bits1, 72(%rax)
+ movq %bits2, 80(%rax)
+ movq %bits3, 88(%rax)
+
+ # Restore registers
+ pop %r15
+ pop %r14
+ pop %r13
+ pop %r12
+ pop %r11
+ pop %r10
+ pop %r9
+ pop %r8
+ pop %rdi
+ pop %rsi
+ pop %rbp
+ pop %rdx
+ pop %rcx
+ pop %rbx
+ pop %rax
+ ret
+#endif
projects / thirdparty / zstd.git / commitdiff
