]>
Commit | Line | Data |
---|---|---|
eee8294c AU |
1 | /* $NetBSD: cephes_subrl.c,v 1.2 2014/10/10 14:06:40 christos Exp $ */ |
2 | ||
3 | /*- | |
4 | * Copyright (c) 2007 The NetBSD Foundation, Inc. | |
5 | * All rights reserved. | |
6 | * | |
7 | * This code is derived from software written by Stephen L. Moshier. | |
8 | * It is redistributed by the NetBSD Foundation by permission of the author. | |
9 | * | |
10 | * Redistribution and use in source and binary forms, with or without | |
11 | * modification, are permitted provided that the following conditions | |
12 | * are met: | |
13 | * 1. Redistributions of source code must retain the above copyright | |
14 | * notice, this list of conditions and the following disclaimer. | |
15 | * 2. Redistributions in binary form must reproduce the above copyright | |
16 | * notice, this list of conditions and the following disclaimer in the | |
17 | * documentation and/or other materials provided with the distribution. | |
18 | * | |
19 | * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS | |
20 | * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED | |
21 | * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
22 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS | |
23 | * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
29 | * POSSIBILITY OF SUCH DAMAGE. | |
30 | */ | |
31 | ||
32 | #include <complex.h> | |
33 | #include <math.h> | |
34 | #include "cephes_subrl.h" | |
35 | ||
36 | /* calculate cosh and sinh */ | |
37 | ||
1ed15161 PM |
38 | /* On platforms where long double is as wide as double. */ |
39 | #ifdef _LDBL_EQ_DBL | |
eee8294c AU |
40 | void |
41 | _cchshl(long double x, long double *c, long double *s) | |
42 | { | |
43 | long double e, ei; | |
44 | ||
45 | if (fabsl(x) <= 0.5L) { | |
46 | *c = coshl(x); | |
47 | *s = sinhl(x); | |
48 | } else { | |
49 | e = expl(x); | |
50 | ei = 0.5L / e; | |
51 | e = 0.5L * e; | |
52 | *s = e - ei; | |
53 | *c = e + ei; | |
54 | } | |
55 | } | |
1ed15161 | 56 | #endif |
eee8294c AU |
57 | |
58 | /* Program to subtract nearest integer multiple of PI */ | |
59 | ||
60 | /* extended precision value of PI: */ | |
61 | static const long double DP1 = 3.14159265358979323829596852490908531763125L; | |
62 | static const long double DP2 = 1.6667485837041756656403424829301998703007e-19L; | |
63 | #ifndef __vax__ | |
64 | static const long double DP3 = 1.8830410776607851167459095484560349402753e-39L; | |
65 | #define MACHEPL 1.1e-38L | |
66 | #else | |
67 | static const long double DP3 = 0L; | |
68 | #define MACHEPL 1.1e-19L | |
69 | #endif | |
70 | ||
71 | long double | |
72 | _redupil(long double x) | |
73 | { | |
74 | long double t; | |
75 | long long i; | |
76 | ||
77 | t = x / M_PIL; | |
78 | if (t >= 0.0L) | |
79 | t += 0.5L; | |
80 | else | |
81 | t -= 0.5L; | |
82 | ||
83 | i = t; /* the multiple */ | |
84 | t = i; | |
85 | t = ((x - t * DP1) - t * DP2) - t * DP3; | |
86 | return t; | |
87 | } | |
88 | ||
89 | /* Taylor series expansion for cosh(2y) - cos(2x) */ | |
90 | ||
1ed15161 PM |
91 | /* On platforms where long double is as wide as double. */ |
92 | #ifdef _LDBL_EQ_DBL | |
eee8294c AU |
93 | long double |
94 | _ctansl(long double complex z) | |
95 | { | |
96 | long double f, x, x2, y, y2, rn, t; | |
97 | long double d; | |
98 | ||
99 | x = fabsl(2.0L * creall(z)); | |
100 | y = fabsl(2.0L * cimagl(z)); | |
101 | ||
102 | x = _redupil(x); | |
103 | ||
104 | x = x * x; | |
105 | y = y * y; | |
106 | x2 = 1.0; | |
107 | y2 = 1.0; | |
108 | f = 1.0; | |
109 | rn = 0.0; | |
110 | d = 0.0; | |
111 | do { | |
112 | rn += 1.0L; | |
113 | f *= rn; | |
114 | rn += 1.0L; | |
115 | f *= rn; | |
116 | x2 *= x; | |
117 | y2 *= y; | |
118 | t = y2 + x2; | |
119 | t /= f; | |
120 | d += t; | |
121 | ||
122 | rn += 1.0L; | |
123 | f *= rn; | |
124 | rn += 1.0L; | |
125 | f *= rn; | |
126 | x2 *= x; | |
127 | y2 *= y; | |
128 | t = y2 - x2; | |
129 | t /= f; | |
130 | d += t; | |
131 | } while (fabsl(t/d) > MACHEPL); | |
132 | return d; | |
133 | } | |
1ed15161 | 134 | #endif |