xs/vendor/github.com/klauspost/reedsolomon/galois_amd64.go

140 lines
2.8 KiB
Go

//go:build !noasm && !appengine && !gccgo
// +build !noasm,!appengine,!gccgo
// Copyright 2015, Klaus Post, see LICENSE for details.
package reedsolomon
//go:noescape
func galMulSSSE3(low, high, in, out []byte)
//go:noescape
func galMulSSSE3Xor(low, high, in, out []byte)
//go:noescape
func galMulAVX2Xor(low, high, in, out []byte)
//go:noescape
func galMulAVX2(low, high, in, out []byte)
//go:noescape
func sSE2XorSlice(in, out []byte)
//go:noescape
func galMulAVX2Xor_64(low, high, in, out []byte)
//go:noescape
func galMulAVX2_64(low, high, in, out []byte)
//go:noescape
func sSE2XorSlice_64(in, out []byte)
// This is what the assembler routines do in blocks of 16 bytes:
/*
func galMulSSSE3(low, high, in, out []byte) {
for n, input := range in {
l := input & 0xf
h := input >> 4
out[n] = low[l] ^ high[h]
}
}
func galMulSSSE3Xor(low, high, in, out []byte) {
for n, input := range in {
l := input & 0xf
h := input >> 4
out[n] ^= low[l] ^ high[h]
}
}
*/
// bigSwitchover is the size where 64 bytes are processed per loop.
const bigSwitchover = 128
func galMulSlice(c byte, in, out []byte, o *options) {
if c == 1 {
copy(out, in)
return
}
if o.useAVX2 {
if len(in) >= bigSwitchover {
galMulAVX2_64(mulTableLow[c][:], mulTableHigh[c][:], in, out)
done := (len(in) >> 6) << 6
in = in[done:]
out = out[done:]
}
if len(in) > 32 {
galMulAVX2(mulTableLow[c][:], mulTableHigh[c][:], in, out)
done := (len(in) >> 5) << 5
in = in[done:]
out = out[done:]
}
} else if o.useSSSE3 {
galMulSSSE3(mulTableLow[c][:], mulTableHigh[c][:], in, out)
done := (len(in) >> 4) << 4
in = in[done:]
out = out[done:]
}
out = out[:len(in)]
mt := mulTable[c][:256]
for i := range in {
out[i] = mt[in[i]]
}
}
func galMulSliceXor(c byte, in, out []byte, o *options) {
if c == 1 {
sliceXor(in, out, o)
return
}
if o.useAVX2 {
if len(in) >= bigSwitchover {
galMulAVX2Xor_64(mulTableLow[c][:], mulTableHigh[c][:], in, out)
done := (len(in) >> 6) << 6
in = in[done:]
out = out[done:]
}
if len(in) >= 32 {
galMulAVX2Xor(mulTableLow[c][:], mulTableHigh[c][:], in, out)
done := (len(in) >> 5) << 5
in = in[done:]
out = out[done:]
}
} else if o.useSSSE3 {
galMulSSSE3Xor(mulTableLow[c][:], mulTableHigh[c][:], in, out)
done := (len(in) >> 4) << 4
in = in[done:]
out = out[done:]
}
if len(in) == 0 {
return
}
out = out[:len(in)]
mt := mulTable[c][:256]
for i := range in {
out[i] ^= mt[in[i]]
}
}
// simple slice xor
func sliceXor(in, out []byte, o *options) {
if o.useSSE2 {
if len(in) >= bigSwitchover {
sSE2XorSlice_64(in, out)
done := (len(in) >> 6) << 6
in = in[done:]
out = out[done:]
}
if len(in) >= 16 {
sSE2XorSlice(in, out)
done := (len(in) >> 4) << 4
in = in[done:]
out = out[done:]
}
}
out = out[:len(in)]
for i := range in {
out[i] ^= in[i]
}
}