xref: /titanic_41/usr/src/common/util/memmove.c (revision 4496171313bed39e96f21bc2f9faf2868e267ae3)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
28 
29 /*	Copyright (c) 1988 AT&T	*/
30 /*	  All Rights Reserved  	*/
31 
32 
33 #if !defined(_KMDB) && !defined(_KERNEL)
34 
35 #pragma weak memmove = _memmove
36 
37 #include "synonyms.h"
38 #endif /* !_KMDB && !_KERNEL */
39 
40 #include <sys/types.h>
41 
42 #if defined(_KERNEL)
43 #include <sys/systm.h>
44 #else
45 #include <string.h>
46 #include <memory.h>
47 #endif
48 
49 /*
50  * Copy s0 to s, always copy n bytes.
51  * Return s
52  * Copying between objects that overlap will take place correctly
53  */
54 void *
55 memmove(void *s, const void *s0, size_t n)
56 {
57 	if (n != 0) {
58 		char *s1 = s;
59 		const char *s2 = s0;
60 
61 		if (s1 <= s2) {
62 			do {
63 				*s1++ = *s2++;
64 			} while (--n != 0);
65 		} else {
66 			s2 += n;
67 			s1 += n;
68 			do {
69 				*--s1 = *--s2;
70 			} while (--n != 0);
71 		}
72 	}
73 	return (s);
74 }
75