1/*	$OpenBSD: bzero.S,v 1.7 2022/12/04 08:22:13 tb Exp $ */
2/*
3 * Written by J.T. Conklin <jtc@netbsd.org>.
4 * Public domain.
5 */
6
7#include "DEFS.h"
8
9ENTRY_NB(bzero)
10	pushl	%edi
11	movl	8(%esp),%edi
12	movl	12(%esp),%edx
13
14	cld				/* set fill direction forward */
15	xorl	%eax,%eax		/* set fill data to 0 */
16
17	/*
18	 * if the string is too short, it's really not worth the overhead
19	 * of aligning to word boundaries, etc.  So we jump to a plain
20	 * unaligned set.
21	 */
22	cmpl	$16,%edx
23	jb	L1
24
25	movl	%edi,%ecx		/* compute misalignment */
26	negl	%ecx
27	andl	$3,%ecx
28	subl	%ecx,%edx
29	rep				/* zero until word aligned */
30	stosb
31
32	movl	%edx,%ecx		/* zero by words */
33	shrl	$2,%ecx
34	andl	$3,%edx
35	rep
36	stosl
37
38L1:	movl	%edx,%ecx		/* zero remainder by bytes */
39	rep
40	stosb
41
42	popl	%edi
43	ret
44END_WEAK(bzero)
45