freebsd-nq/lib/libc/i386/string/strcmp.S

123 lines
3.1 KiB
ArmAsm

/*
* Copyright (c) 1993 Winning Strategies, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Winning Strategies, Inc.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <machine/asm.h>
__FBSDID("$FreeBSD$");
/*
* strcmp(s1, s2)
* return an integer greater than, equal to, or less than 0,
* according as string s1 is greater than, equal to, or less
* than the string s2.
*
* %eax - pointer to s1
* %edx - pointer to s2
*
* Written by:
* J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
*/
/*
* I've unrolled the loop eight times: large enough to make a
* significant difference, and small enough not to totally trash the
* cache.
*/
ENTRY(strcmp)
movl 0x04(%esp),%eax
movl 0x08(%esp),%edx
jmp L2 /* Jump into the loop! */
.align 2,0x90
L1: incl %eax
incl %edx
L2: movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
jne L3
incl %eax
incl %edx
movb (%eax),%cl
testb %cl,%cl
je L3
cmpb %cl,(%edx)
je L1
.align 2, 0x90
L3: movzbl (%eax),%eax /* unsigned comparison */
movzbl (%edx),%edx
subl %edx,%eax
ret
END(strcmp)
.section .note.GNU-stack,"",%progbits