diff options
Diffstat (limited to 'vendor/github.com/klauspost/compress/zstd/seqdec_amd64.go')
| -rw-r--r-- | vendor/github.com/klauspost/compress/zstd/seqdec_amd64.go | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/vendor/github.com/klauspost/compress/zstd/seqdec_amd64.go b/vendor/github.com/klauspost/compress/zstd/seqdec_amd64.go new file mode 100644 index 00000000..847b322a --- /dev/null +++ b/vendor/github.com/klauspost/compress/zstd/seqdec_amd64.go @@ -0,0 +1,362 @@ +//go:build amd64 && !appengine && !noasm && gc +// +build amd64,!appengine,!noasm,gc + +package zstd + +import ( + "fmt" + + "github.com/klauspost/compress/internal/cpuinfo" +) + +type decodeSyncAsmContext struct { + llTable []decSymbol + mlTable []decSymbol + ofTable []decSymbol + llState uint64 + mlState uint64 + ofState uint64 + iteration int + litRemain int + out []byte + outPosition int + literals []byte + litPosition int + history []byte + windowSize int + ll int // set on error (not for all errors, please refer to _generate/gen.go) + ml int // set on error (not for all errors, please refer to _generate/gen.go) + mo int // set on error (not for all errors, please refer to _generate/gen.go) +} + +// sequenceDecs_decodeSync_amd64 implements the main loop of sequenceDecs.decodeSync in x86 asm. +// +// Please refer to seqdec_generic.go for the reference implementation. +//go:noescape +func sequenceDecs_decodeSync_amd64(s *sequenceDecs, br *bitReader, ctx *decodeSyncAsmContext) int + +// sequenceDecs_decodeSync_bmi2 implements the main loop of sequenceDecs.decodeSync in x86 asm with BMI2 extensions. +//go:noescape +func sequenceDecs_decodeSync_bmi2(s *sequenceDecs, br *bitReader, ctx *decodeSyncAsmContext) int + +// sequenceDecs_decodeSync_safe_amd64 does the same as above, but does not write more than output buffer. +//go:noescape +func sequenceDecs_decodeSync_safe_amd64(s *sequenceDecs, br *bitReader, ctx *decodeSyncAsmContext) int + +// sequenceDecs_decodeSync_safe_bmi2 does the same as above, but does not write more than output buffer. +//go:noescape +func sequenceDecs_decodeSync_safe_bmi2(s *sequenceDecs, br *bitReader, ctx *decodeSyncAsmContext) int + +// decode sequences from the stream with the provided history but without a dictionary. +func (s *sequenceDecs) decodeSyncSimple(hist []byte) (bool, error) { + if len(s.dict) > 0 { + return false, nil + } + if s.maxSyncLen == 0 && cap(s.out)-len(s.out) < maxCompressedBlockSize { + return false, nil + } + useSafe := false + if s.maxSyncLen == 0 && cap(s.out)-len(s.out) < maxCompressedBlockSizeAlloc { + useSafe = true + } + if s.maxSyncLen > 0 && cap(s.out)-len(s.out)-compressedBlockOverAlloc < int(s.maxSyncLen) { + useSafe = true + } + if cap(s.literals) < len(s.literals)+compressedBlockOverAlloc { + useSafe = true + } + + br := s.br + + maxBlockSize := maxCompressedBlockSize + if s.windowSize < maxBlockSize { + maxBlockSize = s.windowSize + } + + ctx := decodeSyncAsmContext{ + llTable: s.litLengths.fse.dt[:maxTablesize], + mlTable: s.matchLengths.fse.dt[:maxTablesize], + ofTable: s.offsets.fse.dt[:maxTablesize], + llState: uint64(s.litLengths.state.state), + mlState: uint64(s.matchLengths.state.state), + ofState: uint64(s.offsets.state.state), + iteration: s.nSeqs - 1, + litRemain: len(s.literals), + out: s.out, + outPosition: len(s.out), + literals: s.literals, + windowSize: s.windowSize, + history: hist, + } + + s.seqSize = 0 + startSize := len(s.out) + + var errCode int + if cpuinfo.HasBMI2() { + if useSafe { + errCode = sequenceDecs_decodeSync_safe_bmi2(s, br, &ctx) + } else { + errCode = sequenceDecs_decodeSync_bmi2(s, br, &ctx) + } + } else { + if useSafe { + errCode = sequenceDecs_decodeSync_safe_amd64(s, br, &ctx) + } else { + errCode = sequenceDecs_decodeSync_amd64(s, br, &ctx) + } + } + switch errCode { + case noError: + break + + case errorMatchLenOfsMismatch: + return true, fmt.Errorf("zero matchoff and matchlen (%d) > 0", ctx.ml) + + case errorMatchLenTooBig: + return true, fmt.Errorf("match len (%d) bigger than max allowed length", ctx.ml) + + case errorMatchOffTooBig: + return true, fmt.Errorf("match offset (%d) bigger than current history (%d)", + ctx.mo, ctx.outPosition+len(hist)-startSize) + + case errorNotEnoughLiterals: + return true, fmt.Errorf("unexpected literal count, want %d bytes, but only %d is available", + ctx.ll, ctx.litRemain+ctx.ll) + + case errorNotEnoughSpace: + size := ctx.outPosition + ctx.ll + ctx.ml + if debugDecoder { + println("msl:", s.maxSyncLen, "cap", cap(s.out), "bef:", startSize, "sz:", size-startSize, "mbs:", maxBlockSize, "outsz:", cap(s.out)-startSize) + } + return true, fmt.Errorf("output (%d) bigger than max block size (%d)", size-startSize, maxBlockSize) + + default: + return true, fmt.Errorf("sequenceDecs_decode returned erronous code %d", errCode) + } + + s.seqSize += ctx.litRemain + if s.seqSize > maxBlockSize { + return true, fmt.Errorf("output (%d) bigger than max block size (%d)", s.seqSize, maxBlockSize) + } + err := br.close() + if err != nil { + printf("Closing sequences: %v, %+v\n", err, *br) + return true, err + } + + s.literals = s.literals[ctx.litPosition:] + t := ctx.outPosition + s.out = s.out[:t] + + // Add final literals + s.out = append(s.out, s.literals...) + if debugDecoder { + t += len(s.literals) + if t != len(s.out) { + panic(fmt.Errorf("length mismatch, want %d, got %d", len(s.out), t)) + } + } + + return true, nil +} + +// -------------------------------------------------------------------------------- + +type decodeAsmContext struct { + llTable []decSymbol + mlTable []decSymbol + ofTable []decSymbol + llState uint64 + mlState uint64 + ofState uint64 + iteration int + seqs []seqVals + litRemain int +} + +const noError = 0 + +// error reported when mo == 0 && ml > 0 +const errorMatchLenOfsMismatch = 1 + +// error reported when ml > maxMatchLen +const errorMatchLenTooBig = 2 + +// error reported when mo > available history or mo > s.windowSize +const errorMatchOffTooBig = 3 + +// error reported when the sum of literal lengths exeeceds the literal buffer size +const errorNotEnoughLiterals = 4 + +// error reported when capacity of `out` is too small +const errorNotEnoughSpace = 5 + +// sequenceDecs_decode implements the main loop of sequenceDecs in x86 asm. +// +// Please refer to seqdec_generic.go for the reference implementation. +//go:noescape +func sequenceDecs_decode_amd64(s *sequenceDecs, br *bitReader, ctx *decodeAsmContext) int + +// sequenceDecs_decode implements the main loop of sequenceDecs in x86 asm. +// +// Please refer to seqdec_generic.go for the reference implementation. +//go:noescape +func sequenceDecs_decode_56_amd64(s *sequenceDecs, br *bitReader, ctx *decodeAsmContext) int + +// sequenceDecs_decode implements the main loop of sequenceDecs in x86 asm with BMI2 extensions. +//go:noescape +func sequenceDecs_decode_bmi2(s *sequenceDecs, br *bitReader, ctx *decodeAsmContext) int + +// sequenceDecs_decode implements the main loop of sequenceDecs in x86 asm with BMI2 extensions. +//go:noescape +func sequenceDecs_decode_56_bmi2(s *sequenceDecs, br *bitReader, ctx *decodeAsmContext) int + +// decode sequences from the stream without the provided history. +func (s *sequenceDecs) decode(seqs []seqVals) error { + br := s.br + + maxBlockSize := maxCompressedBlockSize + if s.windowSize < maxBlockSize { + maxBlockSize = s.windowSize + } + + ctx := decodeAsmContext{ + llTable: s.litLengths.fse.dt[:maxTablesize], + mlTable: s.matchLengths.fse.dt[:maxTablesize], + ofTable: s.offsets.fse.dt[:maxTablesize], + llState: uint64(s.litLengths.state.state), + mlState: uint64(s.matchLengths.state.state), + ofState: uint64(s.offsets.state.state), + seqs: seqs, + iteration: len(seqs) - 1, + litRemain: len(s.literals), + } + + s.seqSize = 0 + lte56bits := s.maxBits+s.offsets.fse.actualTableLog+s.matchLengths.fse.actualTableLog+s.litLengths.fse.actualTableLog <= 56 + var errCode int + if cpuinfo.HasBMI2() { + if lte56bits { + errCode = sequenceDecs_decode_56_bmi2(s, br, &ctx) + } else { + errCode = sequenceDecs_decode_bmi2(s, br, &ctx) + } + } else { + if lte56bits { + errCode = sequenceDecs_decode_56_amd64(s, br, &ctx) + } else { + errCode = sequenceDecs_decode_amd64(s, br, &ctx) + } + } + if errCode != 0 { + i := len(seqs) - ctx.iteration - 1 + switch errCode { + case errorMatchLenOfsMismatch: + ml := ctx.seqs[i].ml + return fmt.Errorf("zero matchoff and matchlen (%d) > 0", ml) + + case errorMatchLenTooBig: + ml := ctx.seqs[i].ml + return fmt.Errorf("match len (%d) bigger than max allowed length", ml) + + case errorNotEnoughLiterals: + ll := ctx.seqs[i].ll + return fmt.Errorf("unexpected literal count, want %d bytes, but only %d is available", ll, ctx.litRemain+ll) + } + + return fmt.Errorf("sequenceDecs_decode_amd64 returned erronous code %d", errCode) + } + + if ctx.litRemain < 0 { + return fmt.Errorf("literal count is too big: total available %d, total requested %d", + len(s.literals), len(s.literals)-ctx.litRemain) + } + + s.seqSize += ctx.litRemain + if s.seqSize > maxBlockSize { + return fmt.Errorf("output (%d) bigger than max block size (%d)", s.seqSize, maxBlockSize) + } + err := br.close() + if err != nil { + printf("Closing sequences: %v, %+v\n", err, *br) + } + return err +} + +// -------------------------------------------------------------------------------- + +type executeAsmContext struct { + seqs []seqVals + seqIndex int + out []byte + history []byte + literals []byte + outPosition int + litPosition int + windowSize int +} + +// sequenceDecs_executeSimple_amd64 implements the main loop of sequenceDecs.executeSimple in x86 asm. +// +// Returns false if a match offset is too big. +// +// Please refer to seqdec_generic.go for the reference implementation. +//go:noescape +func sequenceDecs_executeSimple_amd64(ctx *executeAsmContext) bool + +// Same as above, but with safe memcopies +//go:noescape +func sequenceDecs_executeSimple_safe_amd64(ctx *executeAsmContext) bool + +// executeSimple handles cases when dictionary is not used. +func (s *sequenceDecs) executeSimple(seqs []seqVals, hist []byte) error { + // Ensure we have enough output size... + if len(s.out)+s.seqSize+compressedBlockOverAlloc > cap(s.out) { + addBytes := s.seqSize + len(s.out) + compressedBlockOverAlloc + s.out = append(s.out, make([]byte, addBytes)...) + s.out = s.out[:len(s.out)-addBytes] + } + + if debugDecoder { + printf("Execute %d seqs with literals: %d into %d bytes\n", len(seqs), len(s.literals), s.seqSize) + } + + var t = len(s.out) + out := s.out[:t+s.seqSize] + + ctx := executeAsmContext{ + seqs: seqs, + seqIndex: 0, + out: out, + history: hist, + outPosition: t, + litPosition: 0, + literals: s.literals, + windowSize: s.windowSize, + } + var ok bool + if cap(s.literals) < len(s.literals)+compressedBlockOverAlloc { + ok = sequenceDecs_executeSimple_safe_amd64(&ctx) + } else { + ok = sequenceDecs_executeSimple_amd64(&ctx) + } + if !ok { + return fmt.Errorf("match offset (%d) bigger than current history (%d)", + seqs[ctx.seqIndex].mo, ctx.outPosition+len(hist)) + } + s.literals = s.literals[ctx.litPosition:] + t = ctx.outPosition + + // Add final literals + copy(out[t:], s.literals) + if debugDecoder { + t += len(s.literals) + if t != len(out) { + panic(fmt.Errorf("length mismatch, want %d, got %d, ss: %d", len(out), t, s.seqSize)) + } + } + s.out = out + + return nil +} |