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lh9ed821d2023-04-07 01:36:19 -07001/* Complex cosine hyperbole function for double.
2 Copyright (C) 1997-2015 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
5
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
10
11 The GNU C Library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
15
16 You should have received a copy of the GNU Lesser General Public
17 License along with the GNU C Library; if not, see
18 <http://www.gnu.org/licenses/>. */
19
20#include <complex.h>
21#include <fenv.h>
22#include <math.h>
23#include <math_private.h>
24#include <float.h>
25
26__complex__ double
27__ccosh (__complex__ double x)
28{
29 __complex__ double retval;
30 int rcls = fpclassify (__real__ x);
31 int icls = fpclassify (__imag__ x);
32
33 if (__glibc_likely (rcls >= FP_ZERO))
34 {
35 /* Real part is finite. */
36 if (__glibc_likely (icls >= FP_ZERO))
37 {
38 /* Imaginary part is finite. */
39 const int t = (int) ((DBL_MAX_EXP - 1) * M_LN2);
40 double sinix, cosix;
41
42 if (__glibc_likely (fabs (__imag__ x) > DBL_MIN))
43 {
44 __sincos (__imag__ x, &sinix, &cosix);
45 }
46 else
47 {
48 sinix = __imag__ x;
49 cosix = 1.0;
50 }
51
52 if (fabs (__real__ x) > t)
53 {
54 double exp_t = __ieee754_exp (t);
55 double rx = fabs (__real__ x);
56 if (signbit (__real__ x))
57 sinix = -sinix;
58 rx -= t;
59 sinix *= exp_t / 2.0;
60 cosix *= exp_t / 2.0;
61 if (rx > t)
62 {
63 rx -= t;
64 sinix *= exp_t;
65 cosix *= exp_t;
66 }
67 if (rx > t)
68 {
69 /* Overflow (original real part of x > 3t). */
70 __real__ retval = DBL_MAX * cosix;
71 __imag__ retval = DBL_MAX * sinix;
72 }
73 else
74 {
75 double exp_val = __ieee754_exp (rx);
76 __real__ retval = exp_val * cosix;
77 __imag__ retval = exp_val * sinix;
78 }
79 }
80 else
81 {
82 __real__ retval = __ieee754_cosh (__real__ x) * cosix;
83 __imag__ retval = __ieee754_sinh (__real__ x) * sinix;
84 }
85
86 if (fabs (__real__ retval) < DBL_MIN)
87 {
88 volatile double force_underflow
89 = __real__ retval * __real__ retval;
90 (void) force_underflow;
91 }
92 if (fabs (__imag__ retval) < DBL_MIN)
93 {
94 volatile double force_underflow
95 = __imag__ retval * __imag__ retval;
96 (void) force_underflow;
97 }
98 }
99 else
100 {
101 __imag__ retval = __real__ x == 0.0 ? 0.0 : __nan ("");
102 __real__ retval = __nan ("") + __nan ("");
103
104 if (icls == FP_INFINITE)
105 feraiseexcept (FE_INVALID);
106 }
107 }
108 else if (rcls == FP_INFINITE)
109 {
110 /* Real part is infinite. */
111 if (__glibc_likely (icls > FP_ZERO))
112 {
113 /* Imaginary part is finite. */
114 double sinix, cosix;
115
116 if (__glibc_likely (fabs (__imag__ x) > DBL_MIN))
117 {
118 __sincos (__imag__ x, &sinix, &cosix);
119 }
120 else
121 {
122 sinix = __imag__ x;
123 cosix = 1.0;
124 }
125
126 __real__ retval = __copysign (HUGE_VAL, cosix);
127 __imag__ retval = (__copysign (HUGE_VAL, sinix)
128 * __copysign (1.0, __real__ x));
129 }
130 else if (icls == FP_ZERO)
131 {
132 /* Imaginary part is 0.0. */
133 __real__ retval = HUGE_VAL;
134 __imag__ retval = __imag__ x * __copysign (1.0, __real__ x);
135 }
136 else
137 {
138 /* The addition raises the invalid exception. */
139 __real__ retval = HUGE_VAL;
140 __imag__ retval = __nan ("") + __nan ("");
141
142 if (icls == FP_INFINITE)
143 feraiseexcept (FE_INVALID);
144 }
145 }
146 else
147 {
148 __real__ retval = __nan ("");
149 __imag__ retval = __imag__ x == 0.0 ? __imag__ x : __nan ("");
150 }
151
152 return retval;
153}
154weak_alias (__ccosh, ccosh)
155#ifdef NO_LONG_DOUBLE
156strong_alias (__ccosh, __ccoshl)
157weak_alias (__ccosh, ccoshl)
158#endif