ack/lang/cem/libcc.ansi/string/memmove.c

/*
 * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
 * See the copyright notice in the ACK home directory, in the file "Copyright".
 */
/* $Header$ */

#include	<string.h>

void *
memmove(void *s1, const void *s2, register size_t n)
{
	register char *p1 = s1;
	register const char *p2 = s2;

	if (p2 <= p1 && p2 + (n-1) >= p1) {
		/* overlap, copy backwards */
		p1 += n;
		p2 += n;
		while (n > 0) {
			n--;
			*--p1 = *--p2;
		}
	} else
		while (n > 0) {
			n--;
			*p1++ = *p2++;
		}
	return s1;
}