41bdb6e20c
2001-07-06 Paul Eggert <eggert@twinsun.com> * manual/argp.texi: Remove ignored LGPL copyright notice; it's not appropriate for documentation anyway. * manual/libc-texinfo.sh: "Library General Public License" -> "Lesser General Public License". 2001-07-06 Andreas Jaeger <aj@suse.de> * All files under GPL/LGPL version 2: Place under LGPL version 2.1.
64 lines
2.6 KiB
ArmAsm
64 lines
2.6 KiB
ArmAsm
/* Copyright (C) 1998 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Code contributed by Matthew Wilcox <willy@odie.barnet.ac.uk>
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, write to the Free
|
|
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
02111-1307 USA. */
|
|
|
|
#include <sysdep.h>
|
|
|
|
/* size_t strlen(const char *S)
|
|
* entry: r0 -> string
|
|
* exit: r0 = len
|
|
*/
|
|
|
|
ENTRY(strlen)
|
|
bic r1, r0, $3 @ addr of word containing first byte
|
|
ldr r2, [r1], $4 @ get the first word
|
|
ands r3, r0, $3 @ how many bytes are duff?
|
|
rsb r0, r3, $0 @ get - that number into counter.
|
|
beq Laligned @ skip into main check routine if no
|
|
@ more
|
|
#ifdef __ARMEB__
|
|
orr r2, r2, $0xff000000 @ set this byte to non-zero
|
|
subs r3, r3, $1 @ any more to do?
|
|
orrgt r2, r2, $0x00ff0000 @ if so, set this byte
|
|
subs r3, r3, $1 @ more?
|
|
orrgt r2, r2, $0x0000ff00 @ then set.
|
|
#else
|
|
orr r2, r2, $0x000000ff @ set this byte to non-zero
|
|
subs r3, r3, $1 @ any more to do?
|
|
orrgt r2, r2, $0x0000ff00 @ if so, set this byte
|
|
subs r3, r3, $1 @ more?
|
|
orrgt r2, r2, $0x00ff0000 @ then set.
|
|
#endif
|
|
Laligned: @ here, we have a word in r2. Does it
|
|
tst r2, $0x000000ff @ contain any zeroes?
|
|
tstne r2, $0x0000ff00 @
|
|
tstne r2, $0x00ff0000 @
|
|
tstne r2, $0xff000000 @
|
|
addne r0, r0, $4 @ if not, the string is 4 bytes longer
|
|
ldrne r2, [r1], $4 @ and we continue to the next word
|
|
bne Laligned @
|
|
Llastword: @ drop through to here once we find a
|
|
tst r2, $0x000000ff @ word that has a zero byte in it
|
|
addne r0, r0, $1 @
|
|
tstne r2, $0x0000ff00 @ and add up to 3 bytes on to it
|
|
addne r0, r0, $1 @
|
|
tstne r2, $0x00ff0000 @ (if first three all non-zero, 4th
|
|
addne r0, r0, $1 @ must be zero)
|
|
RETINSTR(mov,pc,lr)
|
|
END(strlen)
|