xref: /illumos-gate/usr/src/lib/libc/amd64/gen/wslen.S (revision 55fea89dcaa64928bed4327112404dcb3e07b79f)
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/*
23*5d9d9091SRichard Lowe * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
24*5d9d9091SRichard Lowe * Use is subject to license terms.
25*5d9d9091SRichard Lowe */
26*5d9d9091SRichard Lowe
27*5d9d9091SRichard Lowe	.file	"wslen.s"
28*5d9d9091SRichard Lowe
29*5d9d9091SRichard Lowe/*
30*5d9d9091SRichard Lowe * Wide character wcslen() implementation
31*5d9d9091SRichard Lowe *
32*5d9d9091SRichard Lowe * size_t
33*5d9d9091SRichard Lowe * wcslen(const wchar_t *s)
34*5d9d9091SRichard Lowe *{
35*5d9d9091SRichard Lowe *	const wchar_t *s0 = s + 1;
36*5d9d9091SRichard Lowe *	while (*s++)
37*5d9d9091SRichard Lowe *		;
38*5d9d9091SRichard Lowe *	return (s - s0);
39*5d9d9091SRichard Lowe *}
40*5d9d9091SRichard Lowe */
41*5d9d9091SRichard Lowe
42*5d9d9091SRichard Lowe#include <sys/asm_linkage.h>
43*5d9d9091SRichard Lowe
44*5d9d9091SRichard Lowe	ANSI_PRAGMA_WEAK(wcslen,function)
45*5d9d9091SRichard Lowe	ANSI_PRAGMA_WEAK(wslen,function)
46*5d9d9091SRichard Lowe
47*5d9d9091SRichard Lowe	ENTRY(wcslen)		/* (wchar_t *) */
48*5d9d9091SRichard Lowe	xorl	%eax,%eax
49*5d9d9091SRichard Lowe
50*5d9d9091SRichard Lowe	.align	8
51*5d9d9091SRichard Lowe.loop:
52*5d9d9091SRichard Lowe	cmpl	$0,(%rdi)
53*5d9d9091SRichard Lowe	je	.out0
54*5d9d9091SRichard Lowe	cmpl	$0,4(%rdi)
55*5d9d9091SRichard Lowe	je	.out1
56*5d9d9091SRichard Lowe	cmpl	$0,8(%rdi)
57*5d9d9091SRichard Lowe	je	.out2
58*5d9d9091SRichard Lowe	cmpl	$0,12(%rdi)
59*5d9d9091SRichard Lowe	je	.out3
60*5d9d9091SRichard Lowe	addq	$4,%rax
61*5d9d9091SRichard Lowe	addq	$16,%rdi
62*5d9d9091SRichard Lowe	jmp	.loop
63*5d9d9091SRichard Lowe
64*5d9d9091SRichard Lowe	.align	4
65*5d9d9091SRichard Lowe.out1:
66*5d9d9091SRichard Lowe	incq	%rax
67*5d9d9091SRichard Lowe.out0:
68*5d9d9091SRichard Lowe	ret
69*5d9d9091SRichard Lowe
70*5d9d9091SRichard Lowe	.align	4
71*5d9d9091SRichard Lowe.out2:
72*5d9d9091SRichard Lowe	addq	$2,%rax
73*5d9d9091SRichard Lowe	ret
74*5d9d9091SRichard Lowe
75*5d9d9091SRichard Lowe	.align	4
76*5d9d9091SRichard Lowe.out3:
77*5d9d9091SRichard Lowe	addq	$3, %rax
78*5d9d9091SRichard Lowe	ret
79*5d9d9091SRichard Lowe	SET_SIZE(wcslen)
80*5d9d9091SRichard Lowe
81*5d9d9091SRichard Lowe	ENTRY(wslen)
82*5d9d9091SRichard Lowe	jmp	wcslen		/ tail call into wcslen
83*5d9d9091SRichard Lowe	SET_SIZE(wslen)
84