1 /* $OpenBSD: memchr.S,v 1.1 1997/11/04 19:08:06 chuck Exp $ */
2
3 /*
4 * Written by J.T. Conklin <jtc@netbsd.org>.
5 * Public domain.
6 */
7
8 #include <machine/asm.h>
9
10 ENTRY(memchr)
11 pushl %edi
12 movl 8(%esp),%edi /* string address */
13 movl 12(%esp),%eax /* set character to search for */
14 movl 16(%esp),%ecx /* set length of search */
15 testl %ecx,%ecx /* test for len == 0 */
16 jz L1
17 cld /* set search forward */
18 repne /* search! */
19 scasb
20 jne L1 /* scan failed, return null */
21 leal -1(%edi),%eax /* adjust result of scan */
22 popl %edi
23 ret
24 .align 2,0x90
25 L1: xorl %eax,%eax
26 popl %edi
27 ret