xref: /illumos-gate/usr/src/lib/libm/i386/src/asinf.S (revision 55fea89d)
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 * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
23 */
24/*
25 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26 * Use is subject to license terms.
27 */
28
29        .file "asinf.s"
30
31#include "libm.h"
32LIBM_ANSI_PRAGMA_WEAK(asinf,function)
33#include "libm_protos.h"
34
35	ENTRY(asinf)
36	flds	4(%esp)			/ push x
37	fld1				/ push 1
38	fld	%st(1)			/ x , 1 , x
39	fabs				/ |x| , 1 , x
40	fucomp
41	fstsw  %ax
42	sahf
43	ja	.ERR
44	fadd	%st(1),%st		/ 1+x,x
45	fld1				/ 1,1+x,x
46	fsub	%st(2),%st		/ 1-x,1+x,x
47	fmulp	%st,%st(1)		/ (1-x)*(1+x),x
48	fsqrt				/ sqrt((1-x)*(1+x)),x
49	fpatan				/ atan(x/sqrt((1-x)*(1+x)))
50	ret
51
52.ERR:
53	/ |x| > 1
54	fstp	%st(0)			/ x
55	fstp	%st(0)			/ empty NPX stack
56	fldz
57	fdiv	%st(0),%st		/ 0/0
58	ret
59	.align	4
60	SET_SIZE(asinf)
61