diff options
Diffstat (limited to 'libc/arch-x86/string/memchr.S')
| -rw-r--r-- | libc/arch-x86/string/memchr.S | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/libc/arch-x86/string/memchr.S b/libc/arch-x86/string/memchr.S new file mode 100644 index 0000000..d6bcbe6 --- /dev/null +++ b/libc/arch-x86/string/memchr.S @@ -0,0 +1,26 @@ +/* $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 |