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/*
* 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("$FreeBSD$");
/*
* memcmp (void *b1, void *b2, size_t len)
*
* Written by:
* J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
*/
ENTRY(memcmp)
pushl %edi
pushl %esi
movl 12(%esp),%edi
movl 16(%esp),%esi
cld /* set compare direction forward */
movl 20(%esp),%ecx /* compare by words */
shrl $2,%ecx
repe
cmpsl
jne L5 /* do we match so far? */
movl 20(%esp),%ecx /* compare remainder by bytes */
andl $3,%ecx
repe
cmpsb
jne L6 /* do we match? */
xorl %eax,%eax /* we match, return zero */
popl %esi
popl %edi
ret
L5: movl $4,%ecx /* We know that one of the next */
subl %ecx,%edi /* four pairs of bytes do not */
subl %ecx,%esi /* match. */
repe
cmpsb
L6: movzbl -1(%edi),%eax /* Perform unsigned comparison */
movzbl -1(%esi),%edx
subl %edx,%eax
popl %esi
popl %edi
ret
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