xref: /netbsd-src/external/gpl2/xcvs/dist/lib/memmove.c (revision 5a6c14c844c4c665da5632061aebde7bb2cb5766)
1 /* memmove.c -- copy memory.
2    Copy LENGTH bytes from SOURCE to DEST.  Does not null-terminate.
3    In the public domain.
4    By David MacKenzie <djm@gnu.ai.mit.edu>.  */
5 #include <sys/cdefs.h>
6 __RCSID("$NetBSD: memmove.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
7 
8 #ifdef HAVE_CONFIG_H
9 # include <config.h>
10 #endif
11 
12 #include <stddef.h>
13 
14 void *
memmove(void * dest0,void const * source0,size_t length)15 memmove (void *dest0, void const *source0, size_t length)
16 {
17   char *dest = dest0;
18   char const *source = source0;
19   if (source < dest)
20     /* Moving from low mem to hi mem; start at end.  */
21     for (source += length, dest += length; length; --length)
22       *--dest = *--source;
23   else if (source != dest)
24     {
25       /* Moving from hi mem to low mem; start at beginning.  */
26       for (; length; --length)
27 	*dest++ = *source++;
28     }
29   return dest0;
30 }
31