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 __sinhl = sinhl
31
32 #include "libm.h"
33 #include "longdouble.h"
34
35 /* SINH(X)
36 * RETURN THE HYPERBOLIC SINE OF X
37 *
38 * Method :
39 * 1. reduce x to non-negative by SINH(-x) = - SINH(x).
40 * 2.
41 *
42 * EXPM1(x) + EXPM1(x)/(EXPM1(x)+1)
43 * 0 <= x <= lnovft : SINH(x) := --------------------------------
44 * 2
45 *
46 * lnovft <= x < INF : SINH(x) := EXP(x-MEP1*ln2)*2**ME
47 *
48 * here
49 * lnovft logarithm of the overflow threshold
50 * = MEP1*ln2 chopped to machine precision.
51 * ME maximum exponent
52 * MEP1 maximum exponent plus 1
53 *
54 * Special cases:
55 * SINH(x) is x if x is +INF, -INF, or NaN.
56 * only SINH(0)=0 is exact for finite argument.
57 *
58 */
59
60 static const long double C[] = {
61 0.5L,
62 1.0L,
63 1.135652340629414394879149e+04L,
64 7.004447686242549087858985e-16L
65 };
66
67 #define half C[0]
68 #define one C[1]
69 #define lnovft C[2]
70 #define lnovlo C[3]
71
72 long double
sinhl(long double x)73 sinhl(long double x)
74 {
75 long double r, t;
76
77 if (!finitel(x))
78 return (x + x); /* x is INF or NaN */
79 r = fabsl(x);
80 if (r < lnovft) {
81 t = expm1l(r);
82 r = copysignl((t + t / (one + t)) * half, x);
83 } else {
84 r = copysignl(expl((r - lnovft) - lnovlo), x);
85 r = scalbnl(r, 16383);
86 }
87 return (r);
88 }
89