strchr.S
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/*
* Based on arch/arm/lib/strchr.S
*
* Copyright (C) 1995-2000 Russell King
* Copyright (C) 2013 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* Find the first occurrence of a character in a string.
*
* Parameters:
* x0 - str
* x1 - c
* Returns:
* x0 - address of first occurrence of 'c' or 0
*/
ENTRY(strchr)
and w1, w1, #0xff
1: ldrb w2, [x0], #1
cmp w2, w1
ccmp w2, wzr, #4, ne
b.ne 1b
sub x0, x0, #1
cmp w2, w1
csel x0, x0, xzr, eq
ret
ENDPROC(strchr)