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/* Return value of complex exponential function for a float type.
Copyright (C) 1997-2019 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <complex.h>
#include <fenv.h>
#include <math.h>
#include <math_private.h>
#include <math-underflow.h>
#include <float.h>
CFLOAT
M_DECL_FUNC (__cexp) (CFLOAT x)
{
CFLOAT retval;
int rcls = fpclassify (__real__ x);
int icls = fpclassify (__imag__ x);
if (__glibc_likely (rcls >= FP_ZERO))
{
/* Real part is finite. */
if (__glibc_likely (icls >= FP_ZERO))
{
/* Imaginary part is finite. */
const int t = (int) ((M_MAX_EXP - 1) * M_MLIT (M_LN2));
FLOAT sinix, cosix;
if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))
{
M_SINCOS (__imag__ x, &sinix, &cosix);
}
else
{
sinix = __imag__ x;
cosix = 1;
}
if (__real__ x > t)
{
FLOAT exp_t = M_EXP (t);
__real__ x -= t;
sinix *= exp_t;
cosix *= exp_t;
if (__real__ x > t)
{
__real__ x -= t;
sinix *= exp_t;
cosix *= exp_t;
}
}
if (__real__ x > t)
{
/* Overflow (original real part of x > 3t). */
__real__ retval = M_MAX * cosix;
__imag__ retval = M_MAX * sinix;
}
else
{
FLOAT exp_val = M_EXP (__real__ x);
__real__ retval = exp_val * cosix;
__imag__ retval = exp_val * sinix;
}
math_check_force_underflow_complex (retval);
}
else
{
/* If the imaginary part is +-inf or NaN and the real part
is not +-inf the result is NaN + iNaN. */
__real__ retval = M_NAN;
__imag__ retval = M_NAN;
feraiseexcept (FE_INVALID);
}
}
else if (__glibc_likely (rcls == FP_INFINITE))
{
/* Real part is infinite. */
if (__glibc_likely (icls >= FP_ZERO))
{
/* Imaginary part is finite. */
FLOAT value = signbit (__real__ x) ? 0 : M_HUGE_VAL;
if (icls == FP_ZERO)
{
/* Imaginary part is 0.0. */
__real__ retval = value;
__imag__ retval = __imag__ x;
}
else
{
FLOAT sinix, cosix;
if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))
{
M_SINCOS (__imag__ x, &sinix, &cosix);
}
else
{
sinix = __imag__ x;
cosix = 1;
}
__real__ retval = M_COPYSIGN (value, cosix);
__imag__ retval = M_COPYSIGN (value, sinix);
}
}
else if (signbit (__real__ x) == 0)
{
__real__ retval = M_HUGE_VAL;
__imag__ retval = __imag__ x - __imag__ x;
}
else
{
__real__ retval = 0;
__imag__ retval = M_COPYSIGN (0, __imag__ x);
}
}
else
{
/* If the real part is NaN the result is NaN + iNaN unless the
imaginary part is zero. */
__real__ retval = M_NAN;
if (icls == FP_ZERO)
__imag__ retval = __imag__ x;
else
{
__imag__ retval = M_NAN;
if (rcls != FP_NAN || icls != FP_NAN)
feraiseexcept (FE_INVALID);
}
}
return retval;
}
declare_mgen_alias (__cexp, cexp)
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