summaryrefslogtreecommitdiff
path: root/sys/lib/libkern/arch/i386/bcmp.S
blob: cfe197f82b3f1a0d687f394b8bec17128f4f96d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
/*	$OpenBSD: bcmp.S,v 1.3 2014/11/29 18:51:23 tedu Exp $	*/

/*
 * Written by J.T. Conklin <jtc@netbsd.org>.
 * Public domain.
 */

#include <machine/asm.h>

ENTRY(bcmp)
	pushl	%edi
	pushl	%esi
	movl	12(%esp),%edi
	movl	16(%esp),%esi
	xorl	%eax,%eax		/* clear return value */

	movl	20(%esp),%ecx		/* compare by words */
	shrl	$2,%ecx
	repe
	cmpsl
	jne	L1

	movl	20(%esp),%ecx		/* compare remainder by bytes */
	andl	$3,%ecx
	repe
	cmpsb
	je	L2

L1:	incl	%eax
L2:	popl	%esi
	popl	%edi
	ret