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//go:build gc && !purego
6// +build gc,!purego
7
8package chacha20
9
10import "golang.org/x/sys/cpu"
11
12var haveAsm = cpu.S390X.HasVX
13
14const bufSize = 256
15
16// xorKeyStreamVX is an assembly implementation of XORKeyStream. It must only
17// be called when the vector facility is available. Implementation in asm_s390x.s.
18//go:noescape
19func xorKeyStreamVX(dst, src []byte, key *[8]uint32, nonce *[3]uint32, counter *uint32)
20
21func (c *Cipher) xorKeyStreamBlocks(dst, src []byte) {
22	if cpu.S390X.HasVX {
23		xorKeyStreamVX(dst, src, &c.key, &c.nonce, &c.counter)
24	} else {
25		c.xorKeyStreamBlocksGeneric(dst, src)
26	}
27}
28