xref: /titanic_44/usr/src/lib/libc/i386/gen/wsncmp.s (revision 23c57df72989c916b3e98084eb88d48777999691)
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 (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident	"%Z%%M%	%I%	%E% SMI"
28
29	.file	"%M%"
30
31/
32/ Wide character wcsncpy() implementation
33/
34/ Algorithm based on Solaris 2.6 gen/strncpy.s implementation
35/
36
37#include "SYS.h"
38
39	ANSI_PRAGMA_WEAK(wcsncmp,function)
40	ANSI_PRAGMA_WEAK(wsncmp,function)
41
42	ENTRY(wcsncmp)
43	pushl	%esi		/ save register variables
44	movl	8(%esp),%esi	/ %esi = first string
45	movl	%edi,%edx
46	movl	12(%esp),%edi	/ %edi = second string
47	cmpl	%esi,%edi	/ same string?
48	je	.equal
49	movl	16(%esp),%ecx	/ %ecx = length
50	incl	%ecx		/ will later predecrement this uint
51.loop:
52	decl	%ecx
53	je	.equal		/ Used all n chars?
54	movl	(%esi),%eax	/ slodb ; scab
55	cmpl	(%edi),%eax
56	jne	.notequal_0	/ Are the bytes equal?
57	testl	%eax,%eax
58	je	.equal		/ End of string?
59
60	decl	%ecx
61	je	.equal		/ Used all n chars?
62	movl	4(%esi),%eax	/ slodb ; scab
63	cmpl	4(%edi),%eax
64	jne	.notequal_1	/ Are the bytes equal?
65	testl	%eax,%eax
66	je	.equal		/ End of string?
67
68	decl	%ecx
69	je	.equal		/ Used all n chars?
70	movl	8(%esi),%eax	/ slodb ; scab
71	cmpl	8(%edi),%eax
72	jne	.notequal_2	/ Are the bytes equal?
73	testl	%eax,%eax
74	je	.equal		/ End of string?
75
76	decl	%ecx
77	je	.equal		/ Used all n chars?
78	movl	12(%esi),%eax	/ slodb ; scab
79	cmpl	12(%edi),%eax
80	jne	.notequal_3	/ Are the bytes equal?
81	addl	$16,%esi
82	addl	$16,%edi
83	testl	%eax,%eax
84	jne	.loop		/ End of string?
85
86.equal:
87	popl	%esi		/ restore registers
88	xorl	%eax,%eax	/ return 0
89	movl	%edx,%edi
90	ret
91
92	.align	4
93.notequal_3:
94	addl	$4,%edi
95.notequal_2:
96	addl	$4,%edi
97.notequal_1:
98	addl	$4,%edi
99.notequal_0:
100	popl	%esi		/ restore registers
101	subl	(%edi),%eax	/ return value is (*s1 - *--s2)
102	movl	%edx,%edi
103	ret
104	SET_SIZE(wcsncmp)
105
106	ENTRY(wsncmp)
107	_prologue_
108	movl	_esp_(12),%ecx
109	movl	_esp_(8),%eax
110	movl	_esp_(4),%edx
111	pushl	%ecx
112	pushl	%eax
113	pushl	%edx
114	call	_fref_(wcsncmp)
115	addl	$12,%esp
116	_epilogue_
117	ret
118	SET_SIZE(wsncmp)
119