Retro68/gcc/libgo/go/crypto/sha1/sha1block_amd64.go
2018-12-28 16:30:48 +01:00

37 lines
924 B
Go

// Copyright 2016 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.
// +build ignore
package sha1
import "internal/cpu"
//go:noescape
func blockAVX2(dig *digest, p []byte)
//go:noescape
func blockAMD64(dig *digest, p []byte)
var useAVX2 = cpu.X86.HasAVX2 && cpu.X86.HasBMI1 && cpu.X86.HasBMI2
func block(dig *digest, p []byte) {
if useAVX2 && len(p) >= 256 {
// blockAVX2 calculates sha1 for 2 block per iteration
// it also interleaves precalculation for next block.
// So it may read up-to 192 bytes past end of p
// We may add checks inside blockAVX2, but this will
// just turn it into a copy of blockAMD64,
// so call it directly, instead.
safeLen := len(p) - 128
if safeLen%128 != 0 {
safeLen -= 64
}
blockAVX2(dig, p[:safeLen])
blockAMD64(dig, p[safeLen:])
} else {
blockAMD64(dig, p)
}
}