mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-28 23:34:53 +03:00
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.
76 lines
2.5 KiB
ArmAsm
76 lines
2.5 KiB
ArmAsm
/* Compare two memory blocks for differences in the first COUNT bytes.
|
|
Copyright (C) 1995, 1996, 1997, 2000 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
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>
|
|
#include "asm-syntax.h"
|
|
#include "bp-sym.h"
|
|
#include "bp-asm.h"
|
|
|
|
#define PARMS LINKAGE+4 /* space for 1 saved reg */
|
|
#define BLK1 PARMS
|
|
#define BLK2 BLK1+PTR_SIZE
|
|
#define LEN BLK2+PTR_SIZE
|
|
|
|
.text
|
|
ENTRY (BP_SYM (memcmp))
|
|
ENTER
|
|
|
|
pushl %esi /* Save callee-safe registers. */
|
|
movl %edi, %edx /* Note that %edx is not used and can
|
|
so be used to save %edi. It's faster. */
|
|
|
|
movl BLK1(%esp), %esi
|
|
movl BLK2(%esp), %edi
|
|
movl LEN(%esp), %ecx
|
|
CHECK_BOUNDS_LOW (%esi, BLK1(%esp))
|
|
CHECK_BOUNDS_LOW (%edi, BLK2(%esp))
|
|
|
|
cld /* Set direction of comparison. */
|
|
|
|
xorl %eax, %eax /* Default result. */
|
|
|
|
repe /* Compare at most %ecx bytes. */
|
|
cmpsb
|
|
jz L(1) /* If even last byte was equal we return 0. */
|
|
|
|
/* The memory blocks are not equal. So result of the last
|
|
subtraction is present in the carry flag. It is set when
|
|
the byte in block #2 is bigger. In this case we have to
|
|
return -1 (=0xffffffff), else 1. */
|
|
sbbl %eax, %eax /* This is tricky. %eax == 0 and carry is set
|
|
or not depending on last subtraction. */
|
|
|
|
/* At this point %eax == 0, if the byte of block #1 was bigger, and
|
|
0xffffffff if the last byte of block #2 was bigger. The latter
|
|
case is already correct but the former needs a little adjustment.
|
|
Note that the following operation does not change 0xffffffff. */
|
|
orb $1, %al /* Change 0 to 1. */
|
|
|
|
L(1): CHECK_BOUNDS_HIGH (%esi, BLK1(%esp), jbe)
|
|
CHECK_BOUNDS_HIGH (%edi, BLK2(%esp), jbe)
|
|
popl %esi /* Restore registers. */
|
|
movl %edx, %edi
|
|
|
|
LEAVE
|
|
ret
|
|
END (BP_SYM (memcmp))
|
|
|
|
#undef bcmp
|
|
weak_alias (BP_SYM (memcmp), BP_SYM (bcmp))
|