xref: /titanic_51/usr/src/lib/libm/i386/src/acos.s (revision 8808ac5dae118369991f158b6ab736cb2691ecde)
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_protos.h"
34
35	ENTRY(acos)
36	fldl	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	fldz
46	fucomp
47	fstsw	%ax
48	sahf
49	jp	.L1
50	jne	.L1
51	/ x is -1
52	fstp	%st(0)			/ -1
53	fstp	%st(0)			/ empty NPX stack
54	fldpi
55	ret
56.L1:
57	fxch	%st(1)			/ x,1+x
58	fld1				/ 1,x,1+x
59	fsubp	%st,%st(1)		/ 1-x,1+x
60	fdivp	%st,%st(1)		/ (1-x)/(1+x)
61	fsqrt
62	fld1				/ 1,sqrt((1-x)/(1+x))
63	fpatan
64	fadd	%st(0),%st
65	ret
66
67.ERR:
68	/ |x| > 1
69	pushl   %ebp
70	movl    %esp,%ebp
71	PIC_SETUP(1)
72	fstp	%st(0)			/ x
73	fstp	%st(0)			/ empty NPX stack
74	pushl   $1
75	pushl   12(%ebp)                / high x
76	pushl   8(%ebp)                 / low x
77	pushl   12(%ebp)                / high x
78	pushl   8(%ebp)                 / low x
79	call    PIC_F(_SVID_libm_err)	/ report SVID result/error
80	addl    $20,%esp
81	PIC_WRAPUP
82	leave
83	ret
84	.align	4
85	SET_SIZE(acos)
86