1// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build !gccgo,!purego
6
7package chacha20
8
9import "golang.org/x/sys/cpu"
10
11var haveAsm = cpu.S390X.HasVX
12
13const bufSize = 256
14
15// xorKeyStreamVX is an assembly implementation of XORKeyStream. It must only
16// be called when the vector facility is available. Implementation in asm_s390x.s.
17//go:noescape
18func xorKeyStreamVX(dst, src []byte, key *[8]uint32, nonce *[3]uint32, counter *uint32)
19
20func (c *Cipher) xorKeyStreamBlocks(dst, src []byte) {
21	if cpu.S390X.HasVX {
22		xorKeyStreamVX(dst, src, &c.key, &c.nonce, &c.counter)
23	} else {
24		c.xorKeyStreamBlocksGeneric(dst, src)
25	}
26}
27