xref: /titanic_41/usr/src/lib/libm/common/Q/asinhl.c (revision 2208104ea4cd6d9d44c2a0c21cf2479b92aacf08)
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 __asinhl = asinhl
31 
32 #include "libm.h"
33 
34 static const long double
35 	ln2	= 6.931471805599453094172321214581765680755e-0001L,
36 	one	= 1.0L,
37 	big	= 1.0e+20L,
38 	tiny	= 1.0e-20L;
39 
40 long double
41 asinhl(long double x) {
42 	long double t, w;
43 	volatile long double dummy;
44 
45 	w = fabsl(x);
46 	if (isnanl(x))
47 		return (x + x);	/* x is NaN */
48 	if (w < tiny) {
49 #ifndef lint
50 		dummy = x + big;	/* inexact if x != 0 */
51 #endif
52 		return (x);	/* tiny x */
53 	} else if (w < big) {
54 		t = one / w;
55 		return (copysignl(log1pl(w + w / (t + sqrtl(one + t * t))), x));
56 	} else
57 		return (copysignl(logl(w) + ln2, x));
58 }
59