memmove.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
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 */
54void *
55memmove(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