glibc/sysdeps/i386/i686/strcmp.S

53 lines
1.4 KiB
ArmAsm

/* Highly optimized version for ix86, x>=6.
Copyright (C) 1999-2017 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1999.
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, see
<http://www.gnu.org/licenses/>. */
#include <sysdep.h>
#include "asm-syntax.h"
#define PARMS 4 /* no space for saved regs */
#define STR1 PARMS
#define STR2 STR1+4
.text
ENTRY (strcmp)
movl STR1(%esp), %ecx
movl STR2(%esp), %edx
L(oop): movb (%ecx), %al
cmpb (%edx), %al
jne L(neq)
incl %ecx
incl %edx
testb %al, %al
jnz L(oop)
xorl %eax, %eax
/* when strings are equal, pointers rest one beyond
the end of the NUL terminators. */
ret
L(neq): movl $1, %eax
movl $-1, %ecx
cmovbl %ecx, %eax
ret
END (strcmp)
libc_hidden_builtin_def (strcmp)