41 lines
1.4 KiB
ArmAsm
41 lines
1.4 KiB
ArmAsm
|
/***************************************************************************
|
||
|
|
* __________ __ ___.
|
||
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
||
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
||
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
||
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
||
|
|
* \/ \/ \/ \/ \/
|
||
|
|
* $Id $
|
||
|
|
*
|
||
|
|
* Copyright (C) 2007 Nils Wallménius
|
||
|
|
*
|
||
|
|
* All files in this archive are subject to the GNU General Public License.
|
||
|
|
* See the file COPYING in the source tree root for full license agreement.
|
||
|
|
*
|
||
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
||
|
|
* KIND, either express or implied.
|
||
|
|
*
|
||
|
|
****************************************************************************/
|
||
|
|
|
||
|
|
/* size_t strlen(const char *str) */
|
||
|
|
|
||
|
|
.section .text,"ax",@progbits
|
||
|
|
.align 2
|
||
|
|
.globl strlen
|
||
|
|
.type strlen, @function
|
||
|
|
|
||
|
|
strlen:
|
||
|
|
move.l 4(%sp),%a0 /* %a0 = *str */
|
||
|
|
move.l %a0,%d0 /* %d0 = start address */
|
||
|
|
|
||
|
|
1:
|
||
|
|
tst.b (%a0)+ /* test if %a0 == 0 and increment */
|
||
|
|
bne.b 1b /* if the test was false repeat */
|
||
|
|
|
||
|
|
sub.l %d0,%a0 /* how many times did we repeat? */
|
||
|
|
move.l %a0,%d0
|
||
|
|
subq.l #1,%d0 /* %d0 is 1 too large due to the last increment */
|
||
|
|
rts
|
||
|
|
.size strlen, .-strlen
|
||
|
|
|