1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Based on arch/arm/lib/strrchr.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 last occurrence of a character in a string.
14 *
15 * Parameters:
16 * x0 - str
17 * x1 - c
18 * Returns:
19 * x0 - address of last occurrence of 'c' or 0
20 */
21SYM_FUNC_START(__pi_strrchr)
22 mov x3, #0
23 and w1, w1, #0xff
241: ldrb w2, [x0], #1
25 cbz w2, 2f
26 cmp w2, w1
27 b.ne 1b
28 sub x3, x0, #1
29 b 1b
302: mov x0, x3
31 ret
32SYM_FUNC_END(__pi_strrchr)
33SYM_FUNC_ALIAS_WEAK(strrchr, __pi_strrchr)
34EXPORT_SYMBOL_NOKASAN(strrchr)
35

source code of linux/arch/arm64/lib/strrchr.S