1 | /* Complex cosine hyperbole function for double. |
2 | Copyright (C) 1997-2016 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 | math_check_force_underflow_complex (retval); |
87 | } |
88 | else |
89 | { |
90 | __imag__ retval = __real__ x == 0.0 ? 0.0 : __nan ("" ); |
91 | __real__ retval = __nan ("" ) + __nan ("" ); |
92 | |
93 | if (icls == FP_INFINITE) |
94 | feraiseexcept (FE_INVALID); |
95 | } |
96 | } |
97 | else if (rcls == FP_INFINITE) |
98 | { |
99 | /* Real part is infinite. */ |
100 | if (__glibc_likely (icls > FP_ZERO)) |
101 | { |
102 | /* Imaginary part is finite. */ |
103 | double sinix, cosix; |
104 | |
105 | if (__glibc_likely (fabs (__imag__ x) > DBL_MIN)) |
106 | { |
107 | __sincos (__imag__ x, &sinix, &cosix); |
108 | } |
109 | else |
110 | { |
111 | sinix = __imag__ x; |
112 | cosix = 1.0; |
113 | } |
114 | |
115 | __real__ retval = __copysign (HUGE_VAL, cosix); |
116 | __imag__ retval = (__copysign (HUGE_VAL, sinix) |
117 | * __copysign (1.0, __real__ x)); |
118 | } |
119 | else if (icls == FP_ZERO) |
120 | { |
121 | /* Imaginary part is 0.0. */ |
122 | __real__ retval = HUGE_VAL; |
123 | __imag__ retval = __imag__ x * __copysign (1.0, __real__ x); |
124 | } |
125 | else |
126 | { |
127 | /* The addition raises the invalid exception. */ |
128 | __real__ retval = HUGE_VAL; |
129 | __imag__ retval = __nan ("" ) + __nan ("" ); |
130 | |
131 | if (icls == FP_INFINITE) |
132 | feraiseexcept (FE_INVALID); |
133 | } |
134 | } |
135 | else |
136 | { |
137 | __real__ retval = __nan ("" ); |
138 | __imag__ retval = __imag__ x == 0.0 ? __imag__ x : __nan ("" ); |
139 | } |
140 | |
141 | return retval; |
142 | } |
143 | weak_alias (__ccosh, ccosh) |
144 | #ifdef NO_LONG_DOUBLE |
145 | strong_alias (__ccosh, __ccoshl) |
146 | weak_alias (__ccosh, ccoshl) |
147 | #endif |
148 | |