1 /* Complex cosine hyperbolic function for float types.
2 Copyright (C) 1997-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <complex.h>
20 #include <fenv.h>
21 #include <math.h>
22 #include <math_private.h>
23 #include <math-underflow.h>
24 #include <float.h>
25
26 CFLOAT
M_DECL_FUNC(__ccosh)27 M_DECL_FUNC (__ccosh) (CFLOAT x)
28 {
29 CFLOAT 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) ((M_MAX_EXP - 1) * M_MLIT (M_LN2));
40 FLOAT sinix, cosix;
41
42 if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))
43 {
44 M_SINCOS (__imag__ x, &sinix, &cosix);
45 }
46 else
47 {
48 sinix = __imag__ x;
49 cosix = 1;
50 }
51
52 if (M_FABS (__real__ x) > t)
53 {
54 FLOAT exp_t = M_EXP (t);
55 FLOAT rx = M_FABS (__real__ x);
56 if (signbit (__real__ x))
57 sinix = -sinix;
58 rx -= t;
59 sinix *= exp_t / 2;
60 cosix *= exp_t / 2;
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 = M_MAX * cosix;
71 __imag__ retval = M_MAX * sinix;
72 }
73 else
74 {
75 FLOAT exp_val = M_EXP (rx);
76 __real__ retval = exp_val * cosix;
77 __imag__ retval = exp_val * sinix;
78 }
79 }
80 else
81 {
82 __real__ retval = M_COSH (__real__ x) * cosix;
83 __imag__ retval = M_SINH (__real__ x) * sinix;
84 }
85
86 math_check_force_underflow_complex (retval);
87 }
88 else
89 {
90 __imag__ retval = __real__ x == 0 ? 0 : M_NAN;
91 __real__ retval = __imag__ x - __imag__ x;
92 }
93 }
94 else if (rcls == FP_INFINITE)
95 {
96 /* Real part is infinite. */
97 if (__glibc_likely (icls > FP_ZERO))
98 {
99 /* Imaginary part is finite. */
100 FLOAT sinix, cosix;
101
102 if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))
103 {
104 M_SINCOS (__imag__ x, &sinix, &cosix);
105 }
106 else
107 {
108 sinix = __imag__ x;
109 cosix = 1;
110 }
111
112 __real__ retval = M_COPYSIGN (M_HUGE_VAL, cosix);
113 __imag__ retval = (M_COPYSIGN (M_HUGE_VAL, sinix)
114 * M_COPYSIGN (1, __real__ x));
115 }
116 else if (icls == FP_ZERO)
117 {
118 /* Imaginary part is 0.0. */
119 __real__ retval = M_HUGE_VAL;
120 __imag__ retval = __imag__ x * M_COPYSIGN (1, __real__ x);
121 }
122 else
123 {
124 __real__ retval = M_HUGE_VAL;
125 __imag__ retval = __imag__ x - __imag__ x;
126 }
127 }
128 else
129 {
130 __real__ retval = M_NAN;
131 __imag__ retval = __imag__ x == 0 ? __imag__ x : M_NAN;
132 }
133
134 return retval;
135 }
136
137 declare_mgen_alias (__ccosh, ccosh);
138