xref: /illumos-gate/usr/src/lib/libc/amd64/gen/strchr.S (revision 5d9d9091f564c198a760790b0bfa72c44e17912b)
1*5d9d9091SRichard Lowe/*
2*5d9d9091SRichard Lowe * CDDL HEADER START
3*5d9d9091SRichard Lowe *
4*5d9d9091SRichard Lowe * The contents of this file are subject to the terms of the
5*5d9d9091SRichard Lowe * Common Development and Distribution License (the "License").
6*5d9d9091SRichard Lowe * You may not use this file except in compliance with the License.
7*5d9d9091SRichard Lowe *
8*5d9d9091SRichard Lowe * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9*5d9d9091SRichard Lowe * or http://www.opensolaris.org/os/licensing.
10*5d9d9091SRichard Lowe * See the License for the specific language governing permissions
11*5d9d9091SRichard Lowe * and limitations under the License.
12*5d9d9091SRichard Lowe *
13*5d9d9091SRichard Lowe * When distributing Covered Code, include this CDDL HEADER in each
14*5d9d9091SRichard Lowe * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15*5d9d9091SRichard Lowe * If applicable, add the following below this CDDL HEADER, with the
16*5d9d9091SRichard Lowe * fields enclosed by brackets "[]" replaced with your own identifying
17*5d9d9091SRichard Lowe * information: Portions Copyright [yyyy] [name of copyright owner]
18*5d9d9091SRichard Lowe *
19*5d9d9091SRichard Lowe * CDDL HEADER END
20*5d9d9091SRichard Lowe */
21*5d9d9091SRichard Lowe/*
22*5d9d9091SRichard Lowe * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
23*5d9d9091SRichard Lowe * Use is subject to license terms.
24*5d9d9091SRichard Lowe */
25*5d9d9091SRichard Lowe
26*5d9d9091SRichard Lowe	.file	"strchr.s"
27*5d9d9091SRichard Lowe
28*5d9d9091SRichard Lowe#include "SYS.h"
29*5d9d9091SRichard Lowe
30*5d9d9091SRichard Lowe	ENTRY(strchr)		/* (char *, char) */
31*5d9d9091SRichard Lowe.loop:
32*5d9d9091SRichard Lowe	movb	(%rdi),%dl	/ %dl = byte of string
33*5d9d9091SRichard Lowe	cmpb	%sil,%dl	/ find it?
34*5d9d9091SRichard Lowe	je	.found		/ yes
35*5d9d9091SRichard Lowe	testb	%dl,%dl		/ is it null?
36*5d9d9091SRichard Lowe	je	.notfound
37*5d9d9091SRichard Lowe
38*5d9d9091SRichard Lowe	movb	1(%rdi),%dl	/ %dl = byte of string
39*5d9d9091SRichard Lowe	cmpb	%sil,%dl	/ find it?
40*5d9d9091SRichard Lowe	je	.found1		/ yes
41*5d9d9091SRichard Lowe	testb	%dl,%dl		/ is it null?
42*5d9d9091SRichard Lowe	je	.notfound
43*5d9d9091SRichard Lowe
44*5d9d9091SRichard Lowe	movb	2(%rdi),%dl	/ %dl = byte of string
45*5d9d9091SRichard Lowe	cmpb	%sil,%dl	/ find it?
46*5d9d9091SRichard Lowe	je	.found2		/ yes
47*5d9d9091SRichard Lowe	testb	%dl,%dl		/ is it null?
48*5d9d9091SRichard Lowe	je	.notfound
49*5d9d9091SRichard Lowe
50*5d9d9091SRichard Lowe	movb	3(%rdi),%dl	/ %dl = byte of string
51*5d9d9091SRichard Lowe	cmpb	%sil,%dl	/ find it?
52*5d9d9091SRichard Lowe	je	.found3		/ yes
53*5d9d9091SRichard Lowe	addq	$4,%rdi
54*5d9d9091SRichard Lowe	testb	%dl,%dl		/ is it null?
55*5d9d9091SRichard Lowe	jne	.loop
56*5d9d9091SRichard Lowe
57*5d9d9091SRichard Lowe.notfound:
58*5d9d9091SRichard Lowe	xorl	%eax,%eax	/ %rax = NULL
59*5d9d9091SRichard Lowe	ret
60*5d9d9091SRichard Lowe
61*5d9d9091SRichard Lowe.found3:
62*5d9d9091SRichard Lowe	incq	%rdi
63*5d9d9091SRichard Lowe.found2:
64*5d9d9091SRichard Lowe	incq	%rdi
65*5d9d9091SRichard Lowe.found1:
66*5d9d9091SRichard Lowe	incq	%rdi
67*5d9d9091SRichard Lowe.found:
68*5d9d9091SRichard Lowe	movq	%rdi,%rax
69*5d9d9091SRichard Lowe	ret
70*5d9d9091SRichard Lowe	SET_SIZE(strchr)
71