1/*	$OpenBSD: memcmp.S,v 1.4 2005/08/07 11:30:38 espie Exp $ */
2/*
3 * Written by J.T. Conklin <jtc@netbsd.org>.
4 * Public domain.
5 */
6
7#include <private/bionic_asm.h>
8
9ENTRY(memcmp)
10	pushl	%edi
11	pushl	%esi
12	movl	12(%esp),%edi
13	movl	16(%esp),%esi
14	cld				/* set compare direction forward */
15
16	movl	20(%esp),%ecx		/* compare by words */
17	shrl	$2,%ecx
18	repe
19	cmpsl
20	jne	L5			/* do we match so far? */
21
22	movl	20(%esp),%ecx		/* compare remainder by bytes */
23	andl	$3,%ecx
24	repe
25	cmpsb
26	jne	L6			/* do we match? */
27
28	xorl	%eax,%eax		/* we match, return zero	*/
29	popl	%esi
30	popl	%edi
31	ret
32
33L5:	movl	$4,%ecx			/* We know that one of the next	*/
34	subl	%ecx,%edi		/* four pairs of bytes do not	*/
35	subl	%ecx,%esi		/* match.			*/
36	repe
37	cmpsb
38L6:	movzbl  -1(%edi),%eax		/* Perform unsigned comparison	*/
39	movzbl	-1(%esi),%edx
40	subl	%edx,%eax
41	popl	%esi
42	popl	%edi
43	ret
44END(memcmp)
45