xref: /titanic_51/usr/src/lib/libm/i386/src/acos.s (revision 3f1de28d23e9724b017260ef6b282b278b6e38f9)
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 2006 Sun Microsystems, Inc.  All rights reserved.
26 * Use is subject to license terms.
27 */
28
29        .file "acos.s"
30
31#include "libm.h"
32LIBM_ANSI_PRAGMA_WEAK(acos,function)
33#include "libm_synonyms.h"
34#include "libm_protos.h"
35
36#undef fabs
37
38	ENTRY(acos)
39	fldl	4(%esp)			/ push x
40	fld1				/ push 1
41	fld	%st(1)			/ x , 1 , x
42	fabs				/ |x| , 1 , x
43	fucomp
44	fstsw   %ax
45	sahf
46	ja	.ERR
47	fadd	%st(1),%st		/ 1+x,x
48	fldz
49	fucomp
50	fstsw	%ax
51	sahf
52	jp	.L1
53	jne	.L1
54	/ x is -1
55	fstp	%st(0)			/ -1
56	fstp	%st(0)			/ empty NPX stack
57	fldpi
58	ret
59.L1:
60	fxch	%st(1)			/ x,1+x
61	fld1				/ 1,x,1+x
62	fsubp	%st,%st(1)		/ 1-x,1+x
63	fdivp	%st,%st(1)		/ (1-x)/(1+x)
64	fsqrt
65	fld1				/ 1,sqrt((1-x)/(1+x))
66	fpatan
67	fadd	%st(0),%st
68	ret
69
70.ERR:
71	/ |x| > 1
72	pushl   %ebp
73	movl    %esp,%ebp
74	PIC_SETUP(1)
75	fstp	%st(0)			/ x
76	fstp	%st(0)			/ empty NPX stack
77	pushl   $1
78	pushl   12(%ebp)                / high x
79	pushl   8(%ebp)                 / low x
80	pushl   12(%ebp)                / high x
81	pushl   8(%ebp)                 / low x
82	call    PIC_F(_SVID_libm_err)	/ report SVID result/error
83	addl    $20,%esp
84	PIC_WRAPUP
85	leave
86	ret
87	.align	4
88	SET_SIZE(acos)
89