xref: /openbsd/sys/lib/libkern/bcmp.c (revision 404b540a)
1 /*	$OpenBSD: bcmp.c,v 1.8 2004/11/28 07:23:41 mickey Exp $	*/
2 
3 /*
4  * Copyright (c) 1987 Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #if defined(LIBC_SCCS) && !defined(lint)
33 static char *rcsid = "$OpenBSD: bcmp.c,v 1.8 2004/11/28 07:23:41 mickey Exp $";
34 #endif /* LIBC_SCCS and not lint */
35 
36 #if !defined(_KERNEL) && !defined(_STANDALONE)
37 #include <string.h>
38 #else
39 #include <lib/libkern/libkern.h>
40 #endif
41 
42 /*
43  * bcmp -- vax cmpc3 instruction
44  */
45 int
46 bcmp(b1, b2, length)
47 	const void *b1, *b2;
48 	register size_t length;
49 {
50 	register char *p1, *p2;
51 
52 	if (length == 0)
53 		return(0);
54 	p1 = (char *)b1;
55 	p2 = (char *)b2;
56 	do
57 		if (*p1++ != *p2++)
58 			break;
59 	while (--length);
60 	return(length);
61 }
62