43 строки
1.1 KiB
ArmAsm
43 строки
1.1 KiB
ArmAsm
/*
|
|
* 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)
|