| /* $OpenBSD: memchr.S,v 1.3 2005/08/07 11:30:38 espie Exp $ */ |
| /* |
| * Written by J.T. Conklin <jtc@netbsd.org>. |
| * Public domain. |
| */ |
| |
| #include <machine/asm.h> |
| |
| ENTRY(memchr) |
| pushl %edi |
| movl 8(%esp),%edi /* string address */ |
| movl 12(%esp),%eax /* set character to search for */ |
| movl 16(%esp),%ecx /* set length of search */ |
| testl %ecx,%ecx /* test for len == 0 */ |
| jz L1 |
| cld /* set search forward */ |
| repne /* search! */ |
| scasb |
| jne L1 /* scan failed, return null */ |
| leal -1(%edi),%eax /* adjust result of scan */ |
| popl %edi |
| ret |
| .align 2,0x90 |
| L1: xorl %eax,%eax |
| popl %edi |
| ret |