| 1 | /*␊ |
| 2 | * memmove.c␊ |
| 3 | */␊ |
| 4 | ␊ |
| 5 | #include "libsaio.h"␊ |
| 6 | ␊ |
| 7 | void *memmove(void *dst, const void *src, size_t n)␊ |
| 8 | {␊ |
| 9 | ␉const char *p = src;␊ |
| 10 | ␉char *q = dst;␊ |
| 11 | #if defined(__i386__) || defined(__x86_64__)␊ |
| 12 | ␉if (q < p) {␊ |
| 13 | ␉␉asm volatile("cld; rep; movsb"␊ |
| 14 | ␉␉␉ : "+c" (n), "+S"(p), "+D"(q));␊ |
| 15 | ␉} else {␊ |
| 16 | ␉␉p += (n - 1);␊ |
| 17 | ␉␉q += (n - 1);␊ |
| 18 | ␉␉asm volatile("std; rep; movsb; cld"␊ |
| 19 | ␉␉␉ : "+c" (n), "+S"(p), "+D"(q));␊ |
| 20 | ␉}␊ |
| 21 | #else␊ |
| 22 | ␉if (q < p) {␊ |
| 23 | ␉␉while (n--) {␊ |
| 24 | ␉␉␉*q++ = *p++;␊ |
| 25 | ␉␉}␊ |
| 26 | ␉} else {␊ |
| 27 | ␉␉p += n;␊ |
| 28 | ␉␉q += n;␊ |
| 29 | ␉␉while (n--) {␊ |
| 30 | ␉␉␉*--q = *--p;␊ |
| 31 | ␉␉}␊ |
| 32 | ␉}␊ |
| 33 | #endif␊ |
| 34 | ␊ |
| 35 | ␉return dst;␊ |
| 36 | }␊ |
| 37 | |
