9
10#if 0
11 RCSID("$NetBSD: bzero.S,v 1.2 2003/07/26 19:24:38 salo Exp $")
12#endif
13
14ENTRY(bzero)
15 cld /* set fill direction forward */
16 xorq %rax,%rax /* set fill data to 0 */
17
18 /*
19 * if the string is too short, it's really not worth the overhead
20 * of aligning to word boundries, etc. So we jump to a plain
21 * unaligned set.
22 */
23 cmpq $16,%rsi
24 jb L1
25
26 movq %rdi,%rcx /* compute misalignment */
27 negq %rcx
28 andq $7,%rcx
29 subq %rcx,%rsi
30 rep /* zero until word aligned */
31 stosb
32
33 movq %rsi,%rcx /* zero by words */
34 shrq $3,%rcx
35 andq $7,%rsi
36 rep
37 stosq
38
39L1: movq %rsi,%rcx /* zero remainder by bytes */
40 rep
41 stosb
42
43 ret
| 9
10#if 0
11 RCSID("$NetBSD: bzero.S,v 1.2 2003/07/26 19:24:38 salo Exp $")
12#endif
13
14ENTRY(bzero)
15 cld /* set fill direction forward */
16 xorq %rax,%rax /* set fill data to 0 */
17
18 /*
19 * if the string is too short, it's really not worth the overhead
20 * of aligning to word boundries, etc. So we jump to a plain
21 * unaligned set.
22 */
23 cmpq $16,%rsi
24 jb L1
25
26 movq %rdi,%rcx /* compute misalignment */
27 negq %rcx
28 andq $7,%rcx
29 subq %rcx,%rsi
30 rep /* zero until word aligned */
31 stosb
32
33 movq %rsi,%rcx /* zero by words */
34 shrq $3,%rcx
35 andq $7,%rsi
36 rep
37 stosq
38
39L1: movq %rsi,%rcx /* zero remainder by bytes */
40 rep
41 stosb
42
43 ret
|