ipiq: Add simple IPI latency measure sysctls (2)
[dragonfly.git] / lib / libm / gaps / cephes_subrl.c
CommitLineData
51a20a6e
JM
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
38void
39_cchshl(long double x, long double *c, long double *s)
40{
41 long double e, ei;
42
43 if (fabsl(x) <= 0.5L) {
44 *c = coshl(x);
45 *s = sinhl(x);
46 } else {
47 e = expl(x);
48 ei = 0.5L / e;
49 e = 0.5L * e;
50 *s = e - ei;
51 *c = e + ei;
52 }
53}
54
55/* Program to subtract nearest integer multiple of PI */
56
57/* extended precision value of PI: */
58static const long double DP1 = 3.14159265358979323829596852490908531763125L;
59static const long double DP2 = 1.6667485837041756656403424829301998703007e-19L;
60#ifndef __vax__
61static const long double DP3 = 1.8830410776607851167459095484560349402753e-39L;
62#define MACHEPL 1.1e-38L
63#else
64static const long double DP3 = 0L;
65#define MACHEPL 1.1e-19L
66#endif
67
68long double
69_redupil(long double x)
70{
71 long double t;
72 long long i;
73
74 t = x / M_PIL;
75 if (t >= 0.0L)
76 t += 0.5L;
77 else
78 t -= 0.5L;
79
80 i = t; /* the multiple */
81 t = i;
82 t = ((x - t * DP1) - t * DP2) - t * DP3;
83 return t;
84}
85
86/* Taylor series expansion for cosh(2y) - cos(2x) */
87
88long double
89_ctansl(long double complex z)
90{
91 long double f, x, x2, y, y2, rn, t;
92 long double d;
93
94 x = fabsl(2.0L * creall(z));
95 y = fabsl(2.0L * cimagl(z));
96
97 x = _redupil(x);
98
99 x = x * x;
100 y = y * y;
101 x2 = 1.0;
102 y2 = 1.0;
103 f = 1.0;
104 rn = 0.0;
105 d = 0.0;
106 do {
107 rn += 1.0L;
108 f *= rn;
109 rn += 1.0L;
110 f *= rn;
111 x2 *= x;
112 y2 *= y;
113 t = y2 + x2;
114 t /= f;
115 d += t;
116
117 rn += 1.0L;
118 f *= rn;
119 rn += 1.0L;
120 f *= rn;
121 x2 *= x;
122 y2 *= y;
123 t = y2 - x2;
124 t /= f;
125 d += t;
126 } while (fabsl(t/d) > MACHEPL);
127 return d;
128}