xref: /illumos-gate/usr/src/common/util/memmove.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1988 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
31 
32 #if !defined(_KMDB) && !defined(_KERNEL)
33 
34 #pragma weak _memmove = memmove
35 
36 #include "lint.h"
37 #endif /* !_KMDB && !_KERNEL */
38 
39 #include <sys/types.h>
40 
41 #if defined(_KERNEL)
42 #include <sys/systm.h>
43 #else
44 #include <string.h>
45 #include <memory.h>
46 #endif
47 
48 /*
49  * Copy s0 to s, always copy n bytes.
50  * Return s
51  * Copying between objects that overlap will take place correctly
52  */
53 void *
54 memmove(void *s, const void *s0, size_t n)
55 {
56 	if (n != 0) {
57 		char *s1 = s;
58 		const char *s2 = s0;
59 
60 		if (s1 <= s2) {
61 			do {
62 				*s1++ = *s2++;
63 			} while (--n != 0);
64 		} else {
65 			s2 += n;
66 			s1 += n;
67 			do {
68 				*--s1 = *--s2;
69 			} while (--n != 0);
70 		}
71 	}
72 	return (s);
73 }
74