scc

 1#include <string.h>
 2
 3#undef memmove
 4
 5void *
 6memmove(void *s1, const void *s2, size_t n)
 7{
 8	char *d = s1;
 9	const char *s = s2;
10
11	if (d < s) {
12		while (n-- > 0)
13			*d++ = *s++;
14	} else {
15		s += n-1, d += n-1;
16
17		while (n-- > 0)
18			*d-- = *s--;
19	}
20	return s1;
21}