xref: /linux/arch/arm64/lib/memchr.S (revision cc04a46f11ea046ed53e2c832ae29e4790f7e35f)
1/*
2 * Based on arch/arm/lib/memchr.S
3 *
4 * Copyright (C) 1995-2000 Russell King
5 * Copyright (C) 2013 ARM Ltd.
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include <linux/linkage.h>
21#include <asm/assembler.h>
22
23/*
24 * Find a character in an area of memory.
25 *
26 * Parameters:
27 *	x0 - buf
28 *	x1 - c
29 *	x2 - n
30 * Returns:
31 *	x0 - address of first occurrence of 'c' or 0
32 */
33ENTRY(memchr)
34	and	w1, w1, #0xff
351:	subs	x2, x2, #1
36	b.mi	2f
37	ldrb	w3, [x0], #1
38	cmp	w3, w1
39	b.ne	1b
40	sub	x0, x0, #1
41	ret
422:	mov	x0, #0
43	ret
44ENDPROC(memchr)
45