diff options
Diffstat (limited to 'vendor/github.com/tmthrgd/go-hex/hex_amd64.go')
-rw-r--r-- | vendor/github.com/tmthrgd/go-hex/hex_amd64.go | 94 |
1 files changed, 94 insertions, 0 deletions
diff --git a/vendor/github.com/tmthrgd/go-hex/hex_amd64.go b/vendor/github.com/tmthrgd/go-hex/hex_amd64.go new file mode 100644 index 000000000..0f9f9a5c7 --- /dev/null +++ b/vendor/github.com/tmthrgd/go-hex/hex_amd64.go @@ -0,0 +1,94 @@ +// Copyright 2016 Tom Thorogood. All rights reserved. +// Use of this source code is governed by a +// Modified BSD License license that can be found in +// the LICENSE file. + +// +build amd64,!gccgo,!appengine + +package hex + +import "golang.org/x/sys/cpu" + +// RawEncode encodes src into EncodedLen(len(src)) +// bytes of dst. As a convenience, it returns the number +// of bytes written to dst, but this value is always EncodedLen(len(src)). +// RawEncode implements hexadecimal encoding for a given alphabet. +func RawEncode(dst, src, alpha []byte) int { + if len(alpha) != 16 { + panic("invalid alphabet") + } + + if len(dst) < len(src)*2 { + panic("dst buffer is too small") + } + + if len(src) == 0 { + return 0 + } + + switch { + case cpu.X86.HasAVX: + encodeAVX(&dst[0], &src[0], uint64(len(src)), &alpha[0]) + case cpu.X86.HasSSE41: + encodeSSE(&dst[0], &src[0], uint64(len(src)), &alpha[0]) + default: + encodeGeneric(dst, src, alpha) + } + + return len(src) * 2 +} + +// Decode decodes src into DecodedLen(len(src)) bytes, returning the actual +// number of bytes written to dst. +// +// If Decode encounters invalid input, it returns an error describing the failure. +func Decode(dst, src []byte) (int, error) { + if len(src)%2 != 0 { + return 0, errLength + } + + if len(dst) < len(src)/2 { + panic("dst buffer is too small") + } + + if len(src) == 0 { + return 0, nil + } + + var ( + n uint64 + ok bool + ) + switch { + case cpu.X86.HasAVX: + n, ok = decodeAVX(&dst[0], &src[0], uint64(len(src))) + case cpu.X86.HasSSE41: + n, ok = decodeSSE(&dst[0], &src[0], uint64(len(src))) + default: + n, ok = decodeGeneric(dst, src) + } + + if !ok { + return 0, InvalidByteError(src[n]) + } + + return len(src) / 2, nil +} + +//go:generate go run asm_gen.go + +// This function is implemented in hex_encode_amd64.s +//go:noescape +func encodeAVX(dst *byte, src *byte, len uint64, alpha *byte) + +// This function is implemented in hex_encode_amd64.s +//go:noescape +func encodeSSE(dst *byte, src *byte, len uint64, alpha *byte) + +// This function is implemented in hex_decode_amd64.s +//go:noescape +func decodeAVX(dst *byte, src *byte, len uint64) (n uint64, ok bool) + +// This function is implemented in hex_decode_amd64.s +//go:noescape +func decodeSSE(dst *byte, src *byte, len uint64) (n uint64, ok bool) |