xref: /titanic_44/usr/src/lib/libm/common/LD/asinhl.c (revision f4427914317470f516ca69daaed90f7efb3d76dc)
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 #if defined(ELFOBJ)
31 #pragma weak asinhl = __asinhl
32 #endif
33 
34 #include "libm.h"
35 
36 static const long double
37 	ln2	= 6.931471805599453094172321214581765680755e-0001L,
38 	one	= 1.0L,
39 	big	= 1.0e+20L,
40 	tiny	= 1.0e-20L;
41 
42 long double
43 asinhl(long double x) {
44 	long double t, w;
45 #ifndef lint
46 	volatile long double dummy;
47 #endif
48 
49 	w = fabsl(x);
50 	if (isnanl(x))
51 		return (x + x);	/* x is NaN */
52 	if (w < tiny) {
53 #ifndef lint
54 		dummy = x + big;	/* inexact if x != 0 */
55 #endif
56 		return (x);	/* tiny x */
57 	} else if (w < big) {
58 		t = one / w;
59 		return (copysignl(log1pl(w + w / (t + sqrtl(one + t * t))), x));
60 	} else
61 		return (copysignl(logl(w) + ln2, x));
62 }
63