common/util/memmove.c

	memmove.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */


#if !defined(_KMDB) && !defined(_KERNEL)

#pragma weak memmove = _memmove

#include "synonyms.h"
#endif /* !_KMDB && !_KERNEL */

#include <sys/types.h>

#if defined(_KERNEL)
#include <sys/systm.h>
#else
#include <string.h>
#include <memory.h>
#endif

/*
 * Copy s0 to s, always copy n bytes.
 * Return s
 * Copying between objects that overlap will take place correctly
 */
void *
memmove(void *s, const void *s0, size_t n)
{
    if (n != 0) {
        char *s1 = s;
        const char *s2 = s0;

        if (s1 <= s2) {
            do {
                *s1++ = *s2++;
            } while (--n != 0);
        } else {
            s2 += n;
            s1 += n;
            do {
                *--s1 = *--s2;
            } while (--n != 0);
        }
    }
    return (s);
}