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strlen.S
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/* SPDX-License-Identifier: GPL-2.0 */
/* $Id: strlen.S,v 1.2 2001/06/29 14:07:15 gniibe Exp $
*
* "strlen" implementation of SuperH
*
* Copyright (C) 1999 Kaz Kojima
*
*/
/* size_t strlen (const char *s) */
#include <linux/linkage.h>
ENTRY(strlen)
mov r4,r0
and #3,r0
tst r0,r0
bt/s 1f
mov #0,r2
add #-1,r0
shll2 r0
shll r0
braf r0
nop
mov.b @r4+,r1
tst r1,r1
bt 8f
add #1,r2
mov.b @r4+,r1
tst r1,r1
bt 8f
add #1,r2
mov.b @r4+,r1
tst r1,r1
bt 8f
add #1,r2
1:
mov #0,r3
2:
mov.l @r4+,r1
cmp/str r3,r1
bf/s 2b
add #4,r2
add #-4,r2
#ifndef __LITTLE_ENDIAN__
swap.b r1,r1
swap.w r1,r1
swap.b r1,r1
#endif
extu.b r1,r0
tst r0,r0
bt/s 8f
shlr8 r1
add #1,r2
extu.b r1,r0
tst r0,r0
bt/s 8f
shlr8 r1
add #1,r2
extu.b r1,r0
tst r0,r0
bt 8f
add #1,r2
8:
rts
mov r2,r0