1 /* Return value of complex exponential function for a float type.
2 Copyright (C) 1997-2018 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 "quadmath-imp.h"
21
22 __complex128
cexpq(__complex128 x)23 cexpq (__complex128 x)
24 {
25 __complex128 retval;
26 int rcls = fpclassifyq (__real__ x);
27 int icls = fpclassifyq (__imag__ x);
28
29 if (__glibc_likely (rcls >= QUADFP_ZERO))
30 {
31 /* Real part is finite. */
32 if (__glibc_likely (icls >= QUADFP_ZERO))
33 {
34 /* Imaginary part is finite. */
35 const int t = (int) ((FLT128_MAX_EXP - 1) * M_LN2q);
36 __float128 sinix, cosix;
37
38 if (__glibc_likely (fabsq (__imag__ x) > FLT128_MIN))
39 {
40 sincosq (__imag__ x, &sinix, &cosix);
41 }
42 else
43 {
44 sinix = __imag__ x;
45 cosix = 1;
46 }
47
48 if (__real__ x > t)
49 {
50 __float128 exp_t = expq (t);
51 __real__ x -= t;
52 sinix *= exp_t;
53 cosix *= exp_t;
54 if (__real__ x > t)
55 {
56 __real__ x -= t;
57 sinix *= exp_t;
58 cosix *= exp_t;
59 }
60 }
61 if (__real__ x > t)
62 {
63 /* Overflow (original real part of x > 3t). */
64 __real__ retval = FLT128_MAX * cosix;
65 __imag__ retval = FLT128_MAX * sinix;
66 }
67 else
68 {
69 __float128 exp_val = expq (__real__ x);
70 __real__ retval = exp_val * cosix;
71 __imag__ retval = exp_val * sinix;
72 }
73 math_check_force_underflow_complex (retval);
74 }
75 else
76 {
77 /* If the imaginary part is +-inf or NaN and the real part
78 is not +-inf the result is NaN + iNaN. */
79 __real__ retval = nanq ("");
80 __imag__ retval = nanq ("");
81
82 feraiseexcept (FE_INVALID);
83 }
84 }
85 else if (__glibc_likely (rcls == QUADFP_INFINITE))
86 {
87 /* Real part is infinite. */
88 if (__glibc_likely (icls >= QUADFP_ZERO))
89 {
90 /* Imaginary part is finite. */
91 __float128 value = signbitq (__real__ x) ? 0 : HUGE_VALQ;
92
93 if (icls == QUADFP_ZERO)
94 {
95 /* Imaginary part is 0.0. */
96 __real__ retval = value;
97 __imag__ retval = __imag__ x;
98 }
99 else
100 {
101 __float128 sinix, cosix;
102
103 if (__glibc_likely (fabsq (__imag__ x) > FLT128_MIN))
104 {
105 sincosq (__imag__ x, &sinix, &cosix);
106 }
107 else
108 {
109 sinix = __imag__ x;
110 cosix = 1;
111 }
112
113 __real__ retval = copysignq (value, cosix);
114 __imag__ retval = copysignq (value, sinix);
115 }
116 }
117 else if (signbitq (__real__ x) == 0)
118 {
119 __real__ retval = HUGE_VALQ;
120 __imag__ retval = __imag__ x - __imag__ x;
121 }
122 else
123 {
124 __real__ retval = 0;
125 __imag__ retval = copysignq (0, __imag__ x);
126 }
127 }
128 else
129 {
130 /* If the real part is NaN the result is NaN + iNaN unless the
131 imaginary part is zero. */
132 __real__ retval = nanq ("");
133 if (icls == QUADFP_ZERO)
134 __imag__ retval = __imag__ x;
135 else
136 {
137 __imag__ retval = nanq ("");
138
139 if (rcls != QUADFP_NAN || icls != QUADFP_NAN)
140 feraiseexcept (FE_INVALID);
141 }
142 }
143
144 return retval;
145 }
146