xref: /netbsd-src/external/gpl2/texinfo/dist/lib/memmove.c (revision 29619d2afe564e54d657b83e5a3ae89584f83720)
1 /*	$NetBSD: memmove.c,v 1.1.1.1 2016/01/14 00:11:29 christos Exp $	*/
2 
3 /* memmove.c -- copy memory.
4    Copy LENGTH bytes from SOURCE to DEST.  Does not null-terminate.
5    In the public domain.
6    By David MacKenzie <djm@gnu.ai.mit.edu>.  */
7 
8 #if 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