1 #include <string.h>
2
3 void*
memmove(void * a1,const void * a2,size_t n)4 memmove(void *a1, const void *a2, size_t n)
5 {
6 char *s1, *s2;
7 extern void abort(void);
8
9 if((long)n < 0)
10 abort();
11 if(a1 > a2)
12 goto back;
13 s1 = a1;
14 s2 = a2;
15 while(n > 0) {
16 *s1++ = *s2++;
17 n--;
18 }
19 return a1;
20
21 back:
22 s1 = (char*)a1 + n;
23 s2 = (char*)a2 + n;
24 while(n > 0) {
25 *--s1 = *--s2;
26 n--;
27 }
28 return a1;
29 }
30
31 void*
memcpy(void * a1,const void * a2,size_t n)32 memcpy(void *a1, const void *a2, size_t n)
33 {
34 return memmove(a1, a2, n);
35 }
36