1/*
2 * Written by J.T. Conklin <jtc@NetBSD.org>.
3 * Public domain.
4 * Adapted for NetBSD/x86_64 by Frank van der Linden <fvdl@wasabisystems.com>
5 */
6
7#include <machine/asm.h>
8__FBSDID("$FreeBSD$");
9
10#if 0
11	RCSID("$NetBSD: bzero.S,v 1.2 2003/07/26 19:24:38 salo Exp $")
12#endif
13
14ENTRY(bzero)
15	cld				/* set fill direction forward */
16	xorq	%rax,%rax		/* set fill data to 0 */
17
18	/*
19	 * if the string is too short, it's really not worth the overhead
20	 * of aligning to word boundries, etc.  So we jump to a plain
21	 * unaligned set.
22	 */
23	cmpq	$16,%rsi
24	jb	L1
25
26	movq	%rdi,%rcx		/* compute misalignment */
27	negq	%rcx
28	andq	$7,%rcx
29	subq	%rcx,%rsi
30	rep				/* zero until word aligned */
31	stosb
32
33	movq	%rsi,%rcx		/* zero by words */
34	shrq	$3,%rcx
35	andq	$7,%rsi
36	rep
37	stosq
38
39L1:	movq	%rsi,%rcx		/* zero remainder by bytes */
40	rep
41	stosb
42
43	ret
44END(bzero)
45
46	.section .note.GNU-stack,"",%progbits
47