reedsolomon-go/galois_ppc64le.go

103 lines
2.1 KiB
Go

//go:build !noasm && !appengine && !gccgo
// +build !noasm,!appengine,!gccgo
// Copyright 2015, Klaus Post, see LICENSE for details.
// Copyright 2018, Minio, Inc.
package reedsolomon
//go:noescape
func galMulPpc(low, high, in, out []byte)
//go:noescape
func galMulPpcXor(low, high, in, out []byte)
// This is what the assembler routines do in blocks of 16 bytes:
/*
func galMulPpc(low, high, in, out []byte) {
for n, input := range in {
l := input & 0xf
h := input >> 4
out[n] = low[l] ^ high[h]
}
}
func galMulPpcXor(low, high, in, out []byte) {
for n, input := range in {
l := input & 0xf
h := input >> 4
out[n] ^= low[l] ^ high[h]
}
}
*/
func galMulSlice(c byte, in, out []byte, o *options) {
if c == 1 {
copy(out, in)
return
}
done := (len(in) >> 4) << 4
if done > 0 {
galMulPpc(mulTableLow[c][:], mulTableHigh[c][:], in[:done], out)
}
remain := len(in) - done
if remain > 0 {
mt := mulTable[c][:256]
for i := done; i < len(in); i++ {
out[i] = mt[in[i]]
}
}
}
func galMulSliceXor(c byte, in, out []byte, o *options) {
if c == 1 {
sliceXor(in, out, o)
return
}
done := (len(in) >> 4) << 4
if done > 0 {
galMulPpcXor(mulTableLow[c][:], mulTableHigh[c][:], in[:done], out)
}
remain := len(in) - done
if remain > 0 {
mt := mulTable[c][:256]
for i := done; i < len(in); i++ {
out[i] ^= mt[in[i]]
}
}
}
// slice galois add
func sliceXor(in, out []byte, o *options) {
for n, input := range in {
out[n] ^= input
}
}
// 4-way butterfly
func ifftDIT4(work [][]byte, dist int, log_m01, log_m23, log_m02 ffe, o *options) {
ifftDIT4Ref(work, dist, log_m01, log_m23, log_m02, o)
}
// 4-way butterfly
func fftDIT4(work [][]byte, dist int, log_m01, log_m23, log_m02 ffe, o *options) {
fftDIT4Ref(work, dist, log_m01, log_m23, log_m02, o)
}
// 2-way butterfly forward
func fftDIT2(x, y []byte, log_m ffe, o *options) {
// Reference version:
refMulAdd(x, y, log_m)
sliceXor(x, y, o)
}
// 2-way butterfly inverse
func ifftDIT2(x, y []byte, log_m ffe, o *options) {
// Reference version:
sliceXor(x, y, o)
refMulAdd(x, y, log_m)
}
func mulgf16(x, y []byte, log_m ffe, o *options) {
refMul(x, y, log_m)
}