xs/vendor/github.com/klauspost/reedsolomon/galois_amd64.go
2022-09-12 20:10:51 -07:00

346 lines
7.4 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:]
}
} else {
sliceXorGo(in, out, o)
return
}
out = out[:len(in)]
for i := range in {
out[i] ^= in[i]
}
}
// 4-way butterfly
func ifftDIT4(work [][]byte, dist int, log_m01, log_m23, log_m02 ffe, o *options) {
if len(work[0]) == 0 {
return
}
t01 := &multiply256LUT[log_m01]
t23 := &multiply256LUT[log_m23]
t02 := &multiply256LUT[log_m02]
if o.useAVX512 {
if log_m01 == modulus {
if log_m23 == modulus {
if log_m02 == modulus {
ifftDIT4_avx512_7(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx512_3(work, dist*24, t01, t23, t02)
}
} else {
if log_m02 == modulus {
ifftDIT4_avx512_5(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx512_1(work, dist*24, t01, t23, t02)
}
}
} else {
if log_m23 == modulus {
if log_m02 == modulus {
ifftDIT4_avx512_6(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx512_2(work, dist*24, t01, t23, t02)
}
} else {
if log_m02 == modulus {
ifftDIT4_avx512_4(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx512_0(work, dist*24, t01, t23, t02)
}
}
}
return
} else if o.useAVX2 {
if log_m01 == modulus {
if log_m23 == modulus {
if log_m02 == modulus {
ifftDIT4_avx2_7(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx2_3(work, dist*24, t01, t23, t02)
}
} else {
if log_m02 == modulus {
ifftDIT4_avx2_5(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx2_1(work, dist*24, t01, t23, t02)
}
}
} else {
if log_m23 == modulus {
if log_m02 == modulus {
ifftDIT4_avx2_6(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx2_2(work, dist*24, t01, t23, t02)
}
} else {
if log_m02 == modulus {
ifftDIT4_avx2_4(work, dist*24, t01, t23, t02)
} else {
ifftDIT4_avx2_0(work, dist*24, t01, t23, t02)
}
}
}
return
}
ifftDIT4Ref(work, dist, log_m01, log_m23, log_m02, o)
}
func fftDIT4(work [][]byte, dist int, log_m01, log_m23, log_m02 ffe, o *options) {
if len(work[0]) == 0 {
return
}
t01 := &multiply256LUT[log_m01]
t23 := &multiply256LUT[log_m23]
t02 := &multiply256LUT[log_m02]
if o.useAVX512 {
if log_m02 == modulus {
if log_m01 == modulus {
if log_m23 == modulus {
fftDIT4_avx512_7(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx512_3(work, dist*24, t01, t23, t02)
}
} else {
if log_m23 == modulus {
fftDIT4_avx512_5(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx512_1(work, dist*24, t01, t23, t02)
}
}
} else {
if log_m01 == modulus {
if log_m23 == modulus {
fftDIT4_avx512_6(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx512_2(work, dist*24, t01, t23, t02)
}
} else {
if log_m23 == modulus {
fftDIT4_avx512_4(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx512_0(work, dist*24, t01, t23, t02)
}
}
}
return
} else if o.useAVX2 {
if log_m02 == modulus {
if log_m01 == modulus {
if log_m23 == modulus {
fftDIT4_avx2_7(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx2_3(work, dist*24, t01, t23, t02)
}
} else {
if log_m23 == modulus {
fftDIT4_avx2_5(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx2_1(work, dist*24, t01, t23, t02)
}
}
} else {
if log_m01 == modulus {
if log_m23 == modulus {
fftDIT4_avx2_6(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx2_2(work, dist*24, t01, t23, t02)
}
} else {
if log_m23 == modulus {
fftDIT4_avx2_4(work, dist*24, t01, t23, t02)
} else {
fftDIT4_avx2_0(work, dist*24, t01, t23, t02)
}
}
}
return
}
fftDIT4Ref(work, dist, log_m01, log_m23, log_m02, o)
}
// 2-way butterfly forward
func fftDIT2(x, y []byte, log_m ffe, o *options) {
if o.useAVX2 {
if len(x) > 0 {
tmp := &multiply256LUT[log_m]
fftDIT2_avx2(x, y, tmp)
}
} else if o.useSSSE3 {
if len(x) > 0 {
tmp := &multiply256LUT[log_m]
fftDIT2_ssse3(x, y, tmp)
}
} else {
// Reference version:
refMulAdd(x, y, log_m)
sliceXor(x, y, o)
}
}
// 2-way butterfly
func ifftDIT2(x, y []byte, log_m ffe, o *options) {
if o.useAVX2 {
if len(x) > 0 {
tmp := &multiply256LUT[log_m]
ifftDIT2_avx2(x, y, tmp)
}
} else if o.useSSSE3 {
if len(x) > 0 {
tmp := &multiply256LUT[log_m]
ifftDIT2_ssse3(x, y, tmp)
}
} else {
// Reference version:
sliceXor(x, y, o)
refMulAdd(x, y, log_m)
}
}
func mulgf16(x, y []byte, log_m ffe, o *options) {
if o.useAVX2 {
if len(x) > 0 {
tmp := &multiply256LUT[log_m]
mulgf16_avx2(x, y, tmp)
}
} else if o.useSSSE3 {
if len(x) > 0 {
tmp := &multiply256LUT[log_m]
mulgf16_ssse3(x, y, tmp)
}
} else {
refMul(x, y, log_m)
}
}