glibc/sysdeps/libm-ieee754/s_cexp.c

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/* Return value of complex exponential function for double complex value.
Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <complex.h>
#include <math.h>
__complex__ double
__cexp (__complex__ double x)
{
__complex__ double retval;
if (isfinite (__real__ x))
{
if (isfinite (__imag__ x))
{
retval = __exp (__real__ x) * (__cos (__imag__ x)
+ 1i * __sin (__imag__ x));
}
else
/* If the imaginary part is +-inf or NaN and the real part is
not +-inf the result is NaN + iNan. */
retval = __nan ("") + 1.0i * __nan ("");
}
else if (__isinf (__real__ x))
{
if (isfinite (__imag x))
{
if (signbit (__real__ x) == 0 && __imag__ x == 0.0)
retval = HUGE_VAL;
else
retval = ((signbit (__real__ x) ? 0.0 : HUGE_VAL)
* (__cos (__imag__ x) + 1i * __sin (__imag__ x)));
}
else if (signbit (__real__ x))
retval = HUGE_VAL + 1.0i * __nan ("");
else
retval = 0.0;
}
else
/* If the real part is NaN the result is NaN + iNan. */
retval = __nan ("") + 1.0i * __nan ("");
return retval;
}
weak_alias (__cexp, cexp)