Add MD, optimized versions of string functions for amd64.
[dragonfly.git] / lib / libc / amd64 / string / bcmp.S
1 /*
2  * $NetBSD: bcmp.S,v 1.1 2001/06/19 00:25:04 fvdl Exp $
3  * $FreeBSD: src/lib/libc/amd64/string/bcmp.S,v 1.3 2008/11/02 01:10:54 peter Exp $
4  */
5
6 #include <machine/asm.h>
7
8 ENTRY(bcmp)
9         cld                             /* set compare direction forward */
10
11         movq    %rdx,%rcx               /* compare by words */
12         shrq    $3,%rcx
13         repe
14         cmpsq
15         jne     L1
16
17         movq    %rdx,%rcx               /* compare remainder by bytes */
18         andq    $7,%rcx
19         repe
20         cmpsb
21 L1:
22         setne   %al
23         movsbl  %al,%eax
24         ret
25 END(bcmp)