xref: /freebsd/lib/libc/i386/string/bcmp.S (revision 8af1452cf8dd1b33da881f84e445d5981eaa9613)
1/*
2 * Copyright (c) 1993 Winning Strategies, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *      This product includes software developed by Winning Strategies, Inc.
16 * 4. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#if defined(LIBC_RCS) && !defined(lint)
32	.text
33        .asciz "$FreeBSD$"
34#endif /* LIBC_RCS and not lint */
35
36#include "DEFS.h"
37
38/*
39 * bcmp (void *b1, void *b2, size_t len)
40 *
41 * Written by:
42 *	J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
43 */
44
45ENTRY(bcmp)
46	pushl	%edi
47	pushl	%esi
48	movl	12(%esp),%edi
49	movl	16(%esp),%esi
50	xorl	%eax,%eax		/* clear return value */
51	cld				/* set compare direction forward */
52
53	movl	20(%esp),%ecx		/* compare by words */
54	shrl	$2,%ecx
55	repe
56	cmpsl
57	jne	L1
58
59	movl	20(%esp),%ecx		/* compare remainder by bytes */
60	andl	$3,%ecx
61	repe
62	cmpsb
63	je	L2
64
65L1:	incl	%eax
66L2:	popl	%esi
67	popl	%edi
68	ret
69