diff options
Diffstat (limited to 'libc/arch-x86/string/strlen.S')
| -rw-r--r-- | libc/arch-x86/string/strlen.S | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/libc/arch-x86/string/strlen.S b/libc/arch-x86/string/strlen.S new file mode 100644 index 0000000..4f04ffc --- /dev/null +++ b/libc/arch-x86/string/strlen.S @@ -0,0 +1,20 @@ +/* $OpenBSD: strlen.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(strlen) + pushl %edi + movl 8(%esp),%edi /* string address */ + cld /* set search forward */ + xorl %eax,%eax /* set search for null terminator */ + movl $-1,%ecx /* set search for lots of characters */ + repne /* search! */ + scasb + notl %ecx /* get length by taking complement */ + leal -1(%ecx),%eax /* and subtracting one */ + popl %edi + ret |