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feb62dda | 1 | /* Return value of complex exponential function for a float type. |
2b778ceb | 2 | Copyright (C) 1997-2021 Free Software Foundation, Inc. |
1dbc54f6 PM |
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 | |
5a82c748 | 18 | <https://www.gnu.org/licenses/>. */ |
1dbc54f6 PM |
19 | |
20 | #include <complex.h> | |
21 | #include <fenv.h> | |
22 | #include <math.h> | |
23 | #include <math_private.h> | |
8f5b00d3 | 24 | #include <math-underflow.h> |
1dbc54f6 PM |
25 | #include <float.h> |
26 | ||
feb62dda PM |
27 | CFLOAT |
28 | M_DECL_FUNC (__cexp) (CFLOAT x) | |
1dbc54f6 | 29 | { |
feb62dda | 30 | CFLOAT retval; |
1dbc54f6 PM |
31 | int rcls = fpclassify (__real__ x); |
32 | int icls = fpclassify (__imag__ x); | |
33 | ||
34 | if (__glibc_likely (rcls >= FP_ZERO)) | |
35 | { | |
36 | /* Real part is finite. */ | |
37 | if (__glibc_likely (icls >= FP_ZERO)) | |
38 | { | |
39 | /* Imaginary part is finite. */ | |
feb62dda PM |
40 | const int t = (int) ((M_MAX_EXP - 1) * M_MLIT (M_LN2)); |
41 | FLOAT sinix, cosix; | |
1dbc54f6 | 42 | |
feb62dda | 43 | if (__glibc_likely (M_FABS (__imag__ x) > M_MIN)) |
1dbc54f6 | 44 | { |
feb62dda | 45 | M_SINCOS (__imag__ x, &sinix, &cosix); |
1dbc54f6 PM |
46 | } |
47 | else | |
48 | { | |
49 | sinix = __imag__ x; | |
feb62dda | 50 | cosix = 1; |
1dbc54f6 PM |
51 | } |
52 | ||
53 | if (__real__ x > t) | |
54 | { | |
feb62dda | 55 | FLOAT exp_t = M_EXP (t); |
1dbc54f6 PM |
56 | __real__ x -= t; |
57 | sinix *= exp_t; | |
58 | cosix *= exp_t; | |
59 | if (__real__ x > t) | |
60 | { | |
61 | __real__ x -= t; | |
62 | sinix *= exp_t; | |
63 | cosix *= exp_t; | |
64 | } | |
65 | } | |
66 | if (__real__ x > t) | |
67 | { | |
68 | /* Overflow (original real part of x > 3t). */ | |
feb62dda PM |
69 | __real__ retval = M_MAX * cosix; |
70 | __imag__ retval = M_MAX * sinix; | |
1dbc54f6 PM |
71 | } |
72 | else | |
73 | { | |
feb62dda | 74 | FLOAT exp_val = M_EXP (__real__ x); |
1dbc54f6 PM |
75 | __real__ retval = exp_val * cosix; |
76 | __imag__ retval = exp_val * sinix; | |
77 | } | |
78 | math_check_force_underflow_complex (retval); | |
79 | } | |
80 | else | |
81 | { | |
82 | /* If the imaginary part is +-inf or NaN and the real part | |
83 | is not +-inf the result is NaN + iNaN. */ | |
feb62dda PM |
84 | __real__ retval = M_NAN; |
85 | __imag__ retval = M_NAN; | |
1dbc54f6 PM |
86 | |
87 | feraiseexcept (FE_INVALID); | |
88 | } | |
89 | } | |
90 | else if (__glibc_likely (rcls == FP_INFINITE)) | |
91 | { | |
92 | /* Real part is infinite. */ | |
93 | if (__glibc_likely (icls >= FP_ZERO)) | |
94 | { | |
95 | /* Imaginary part is finite. */ | |
feb62dda | 96 | FLOAT value = signbit (__real__ x) ? 0 : M_HUGE_VAL; |
1dbc54f6 PM |
97 | |
98 | if (icls == FP_ZERO) | |
99 | { | |
100 | /* Imaginary part is 0.0. */ | |
101 | __real__ retval = value; | |
102 | __imag__ retval = __imag__ x; | |
103 | } | |
104 | else | |
105 | { | |
feb62dda | 106 | FLOAT sinix, cosix; |
1dbc54f6 | 107 | |
feb62dda | 108 | if (__glibc_likely (M_FABS (__imag__ x) > M_MIN)) |
1dbc54f6 | 109 | { |
feb62dda | 110 | M_SINCOS (__imag__ x, &sinix, &cosix); |
1dbc54f6 PM |
111 | } |
112 | else | |
113 | { | |
114 | sinix = __imag__ x; | |
feb62dda | 115 | cosix = 1; |
1dbc54f6 PM |
116 | } |
117 | ||
feb62dda PM |
118 | __real__ retval = M_COPYSIGN (value, cosix); |
119 | __imag__ retval = M_COPYSIGN (value, sinix); | |
1dbc54f6 PM |
120 | } |
121 | } | |
122 | else if (signbit (__real__ x) == 0) | |
123 | { | |
feb62dda | 124 | __real__ retval = M_HUGE_VAL; |
e886c367 | 125 | __imag__ retval = __imag__ x - __imag__ x; |
1dbc54f6 PM |
126 | } |
127 | else | |
128 | { | |
feb62dda PM |
129 | __real__ retval = 0; |
130 | __imag__ retval = M_COPYSIGN (0, __imag__ x); | |
1dbc54f6 PM |
131 | } |
132 | } | |
133 | else | |
134 | { | |
135 | /* If the real part is NaN the result is NaN + iNaN unless the | |
136 | imaginary part is zero. */ | |
feb62dda | 137 | __real__ retval = M_NAN; |
1dbc54f6 PM |
138 | if (icls == FP_ZERO) |
139 | __imag__ retval = __imag__ x; | |
140 | else | |
141 | { | |
feb62dda | 142 | __imag__ retval = M_NAN; |
1dbc54f6 PM |
143 | |
144 | if (rcls != FP_NAN || icls != FP_NAN) | |
145 | feraiseexcept (FE_INVALID); | |
146 | } | |
147 | } | |
148 | ||
149 | return retval; | |
150 | } | |
feb62dda | 151 | declare_mgen_alias (__cexp, cexp) |