1/* 2 * Written by J.T. Conklin <jtc@netbsd.org>. 3 * Public domain. 4 */ 5 6#include <machine/asm.h> 7 8#if defined(LIBC_SCCS) 9 .text 10 .asciz "$OpenBSD: memchr.S,v 1.2 1996/08/19 08:13:01 tholo Exp $" 11#endif 12 13ENTRY(memchr) 14 pushl %edi 15 movl 8(%esp),%edi /* string address */ 16 movl 12(%esp),%eax /* set character to search for */ 17 movl 16(%esp),%ecx /* set length of search */ 18 testl %ecx,%ecx /* test for len == 0 */ 19 jz L1 20 cld /* set search forward */ 21 repne /* search! */ 22 scasb 23 jne L1 /* scan failed, return null */ 24 leal -1(%edi),%eax /* adjust result of scan */ 25 popl %edi 26 ret 27 .align 2,0x90 28L1: xorl %eax,%eax 29 popl %edi 30 ret 31