Update.
[glibc.git] / sysdeps / libm-ieee754 / s_cexp.c
blob6ba5b0a4a5a65ba47ad456303c15e6e29ae4d860
1 /* Return value of complex exponential function for double complex value.
2 Copyright (C) 1997 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
6 The GNU C Library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Library General Public License as
8 published by the Free Software Foundation; either version 2 of the
9 License, or (at your option) any later version.
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 Library General Public License for more details.
16 You should have received a copy of the GNU Library General Public
17 License along with the GNU C Library; see the file COPYING.LIB. If not,
18 write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 Boston, MA 02111-1307, USA. */
21 #include <complex.h>
22 #include <fenv.h>
23 #include <math.h>
25 #include "math_private.h"
28 __complex__ double
29 __cexp (__complex__ double x)
31 __complex__ double retval;
32 int rcls = fpclassify (__real__ x);
33 int icls = fpclassify (__imag__ x);
35 if (rcls >= FP_ZERO)
37 /* Real part is finite. */
38 if (icls >= FP_ZERO)
40 /* Imaginary part is finite. */
41 double exp_val = __ieee754_exp (__real__ x);
42 double sinix, cosix;
44 __sincos (__imag__ x, &sinix, &cosix);
46 if (isfinite (exp_val))
48 __real__ retval = exp_val * cosix;
49 __imag__ retval = exp_val * sinix;
51 else
53 __real__ retval = __copysign (exp_val, cosix);
54 __imag__ retval = __copysign (exp_val, sinix);
57 else
59 /* If the imaginary part is +-inf or NaN and the real part
60 is not +-inf the result is NaN + iNaN. */
61 __real__ retval = __nan ("");
62 __imag__ retval = __nan ("");
64 #ifdef FE_INVALID
65 feraiseexcept (FE_INVALID);
66 #endif
69 else if (rcls == FP_INFINITE)
71 /* Real part is infinite. */
72 if (icls >= FP_ZERO)
74 /* Imaginary part is finite. */
75 double value = signbit (__real__ x) ? 0.0 : HUGE_VAL;
77 if (icls == FP_ZERO)
79 /* Imaginary part is 0.0. */
80 __real__ retval = value;
81 __imag__ retval = __imag__ x;
83 else
85 double sinix, cosix;
87 __sincos (__imag__ x, &sinix, &cosix);
89 __real__ retval = __copysign (value, cosix);
90 __imag__ retval = __copysign (value, sinix);
93 else if (signbit (__real__ x) == 0)
95 __real__ retval = HUGE_VAL;
96 __imag__ retval = __nan ("");
98 #ifdef FE_INVALID
99 if (icls == FP_INFINITE)
100 feraiseexcept (FE_INVALID);
101 #endif
103 else
105 __real__ retval = 0.0;
106 __imag__ retval = __copysign (0.0, __imag__ x);
109 else
111 /* If the real part is NaN the result is NaN + iNaN. */
112 __real__ retval = __nan ("");
113 __imag__ retval = __nan ("");
115 #ifdef FE_INVALID
116 if (rcls != FP_NAN || icls != FP_NAN)
117 feraiseexcept (FE_INVALID);
118 #endif
121 return retval;
123 weak_alias (__cexp, cexp)
124 #ifdef NO_LONG_DOUBLE
125 strong_alias (__cexp, __cexpl)
126 weak_alias (__cexp, cexpl)
127 #endif