memmove.c revision 7257d1b4d25bfac0c802847390e98a464fd787ac
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 */
53void *
54memmove(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