strchr.S

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2/*
 3 * Based on arch/arm/lib/strchr.S
 4 *
 5 * Copyright (C) 1995-2000 Russell King
 6 * Copyright (C) 2013 ARM Ltd.
 7 */
 8
 9#include <linux/linkage.h>
10#include <asm/assembler.h>
11
12/*
13 * Find the first occurrence of a character in a string.
14 *
15 * Parameters:
16 *	x0 - str
17 *	x1 - c
18 * Returns:
19 *	x0 - address of first occurrence of 'c' or 0
20 */
21SYM_FUNC_START(__pi_strchr)
22	and	w1, w1, #0xff
231:	ldrb	w2, [x0], #1
24	cmp	w2, w1
25	ccmp	w2, wzr, #4, ne
26	b.ne	1b
27	sub	x0, x0, #1
28	cmp	w2, w1
29	csel	x0, x0, xzr, eq
30	ret
31SYM_FUNC_END(__pi_strchr)
32
33SYM_FUNC_ALIAS_WEAK(strchr, __pi_strchr)
34EXPORT_SYMBOL_NOKASAN(strchr)