xref: /titanic_41/usr/src/lib/libm/common/complex/cacoshl.c (revision 018207534e5d18020ddb86fea48c6d68c7a2626d)
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 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 #pragma weak cacoshl = __cacoshl
31 
32 #include "libm.h"	/* fabsl/isnanl/isinfl/signbitl */
33 #include "complex_wrapper.h"
34 #include "longdouble.h"
35 
36 /* INDENT OFF */
37 /*
38  * ldcomplex cacoshl(ldcomplex z);
39  *	cacosh z = +-i cacos z .
40  * In order to make conj(cacosh(z))=cacosh(conj(z)),
41  * we define
42  *	cacosh z = sign(Im(z))*i cacos z .
43  *
44  */
45 /* INDENT ON */
46 
47 ldcomplex
48 cacoshl(ldcomplex z) {
49 	ldcomplex w, ans;
50 	long double x, y;
51 
52 	w = cacosl(z);
53 	x = LD_RE(z);
54 	y = LD_IM(z);
55 	if (isnanl(y)) {
56 		LD_IM(ans) = y + y;
57 		if (isinfl(x))
58 			LD_RE(ans) = fabsl(x);
59 		else
60 			LD_RE(ans) = y;
61 	} else if (signbitl(y) == 0) {
62 		LD_RE(ans) = -LD_IM(w);
63 		LD_IM(ans) = LD_RE(w);
64 	} else {
65 		LD_RE(ans) = LD_IM(w);
66 		LD_IM(ans) = -LD_RE(w);
67 	}
68 	return (ans);
69 }
70