xref: /titanic_41/usr/src/lib/libc/amd64/gen/strchr.s (revision 4bff34e37def8a90f9194d81bc345c52ba20086a)
1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License").  You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27	.ident	"%Z%%M%	%I%	%E% SMI"
28
29	.file	"%M%"
30
31#include "SYS.h"
32
33	ENTRY(strchr)		/* (char *, char) */
34.loop:
35	movb	(%rdi),%dl	/ %dl = byte of string
36	cmpb	%sil,%dl	/ find it?
37	je	.found		/ yes
38	testb	%dl,%dl		/ is it null?
39	je	.notfound
40
41	movb	1(%rdi),%dl	/ %dl = byte of string
42	cmpb	%sil,%dl	/ find it?
43	je	.found1		/ yes
44	testb	%dl,%dl		/ is it null?
45	je	.notfound
46
47	movb	2(%rdi),%dl	/ %dl = byte of string
48	cmpb	%sil,%dl	/ find it?
49	je	.found2		/ yes
50	testb	%dl,%dl		/ is it null?
51	je	.notfound
52
53	movb	3(%rdi),%dl	/ %dl = byte of string
54	cmpb	%sil,%dl	/ find it?
55	je	.found3		/ yes
56	addq	$4,%rdi
57	testb	%dl,%dl		/ is it null?
58	jne	.loop
59
60.notfound:
61	xorl	%eax,%eax	/ %rax = NULL
62	ret
63
64.found3:
65	incq	%rdi
66.found2:
67	incq	%rdi
68.found1:
69	incq	%rdi
70.found:
71	movq	%rdi,%rax
72	ret
73	SET_SIZE(strchr)
74