mirror of
https://github.com/emmansun/gmsm.git
synced 2025-04-26 04:06:18 +08:00
33 lines
743 B
Go
33 lines
743 B
Go
// Copyright 2018 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
//
|
|
//go:build amd64 && !purego
|
|
// +build amd64,!purego
|
|
|
|
package subtle
|
|
|
|
import "golang.org/x/sys/cpu"
|
|
|
|
var useAVX2 = cpu.X86.HasAVX2
|
|
|
|
// XORBytes xors the bytes in a and b. The destination should have enough
|
|
// space, otherwise XORBytes will panic. Returns the number of bytes xor'd.
|
|
func XORBytes(dst, a, b []byte) int {
|
|
n := len(a)
|
|
if len(b) < n {
|
|
n = len(b)
|
|
}
|
|
if n == 0 {
|
|
return 0
|
|
}
|
|
if n > len(dst) {
|
|
panic("subtle.XORBytes: dst too short")
|
|
}
|
|
xorBytes(&dst[0], &a[0], &b[0], n) // amd64 must have SSE2
|
|
return n
|
|
}
|
|
|
|
//go:noescape
|
|
func xorBytes(dst, a, b *byte, n int)
|