mirror of
https://github.com/autc04/Retro68.git
synced 2024-11-28 05:51:04 +00:00
121 lines
3.1 KiB
C
121 lines
3.1 KiB
C
/* Complex hyperbole tangent for __float128.
|
|
Copyright (C) 1997-2012 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 "quadmath-imp.h"
|
|
|
|
#ifdef HAVE_FENV_H
|
|
# include <fenv.h>
|
|
#endif
|
|
|
|
|
|
__complex128
|
|
ctanhq (__complex128 x)
|
|
{
|
|
__complex128 res;
|
|
|
|
if (__builtin_expect (!finiteq (__real__ x) || !finiteq (__imag__ x), 0))
|
|
{
|
|
if (__quadmath_isinf_nsq (__real__ x))
|
|
{
|
|
__real__ res = copysignq (1.0Q, __real__ x);
|
|
__imag__ res = copysignq (0.0Q, __imag__ x);
|
|
}
|
|
else if (__imag__ x == 0.0Q)
|
|
{
|
|
res = x;
|
|
}
|
|
else
|
|
{
|
|
__real__ res = nanq ("");
|
|
__imag__ res = nanq ("");
|
|
|
|
#ifdef HAVE_FENV_H
|
|
if (__quadmath_isinf_nsq (__imag__ x))
|
|
feraiseexcept (FE_INVALID);
|
|
#endif
|
|
}
|
|
}
|
|
else
|
|
{
|
|
__float128 sinix, cosix;
|
|
__float128 den;
|
|
const int t = (int) ((FLT128_MAX_EXP - 1) * M_LN2q / 2);
|
|
int icls = fpclassifyq (__imag__ x);
|
|
|
|
/* tanh(x+iy) = (sinh(2x) + i*sin(2y))/(cosh(2x) + cos(2y))
|
|
= (sinh(x)*cosh(x) + i*sin(y)*cos(y))/(sinh(x)^2 + cos(y)^2). */
|
|
|
|
if (__builtin_expect (icls != QUADFP_SUBNORMAL, 1))
|
|
{
|
|
sincosq (__imag__ x, &sinix, &cosix);
|
|
}
|
|
else
|
|
{
|
|
sinix = __imag__ x;
|
|
cosix = 1.0Q;
|
|
}
|
|
|
|
if (fabsq (__real__ x) > t)
|
|
{
|
|
/* Avoid intermediate overflow when the imaginary part of
|
|
the result may be subnormal. Ignoring negligible terms,
|
|
the real part is +/- 1, the imaginary part is
|
|
sin(y)*cos(y)/sinh(x)^2 = 4*sin(y)*cos(y)/exp(2x). */
|
|
__float128 exp_2t = expq (2 * t);
|
|
|
|
__real__ res = copysignq (1.0, __real__ x);
|
|
__imag__ res = 4 * sinix * cosix;
|
|
__real__ x = fabsq (__real__ x);
|
|
__real__ x -= t;
|
|
__imag__ res /= exp_2t;
|
|
if (__real__ x > t)
|
|
{
|
|
/* Underflow (original real part of x has absolute value
|
|
> 2t). */
|
|
__imag__ res /= exp_2t;
|
|
}
|
|
else
|
|
__imag__ res /= expq (2 * __real__ x);
|
|
}
|
|
else
|
|
{
|
|
__float128 sinhrx, coshrx;
|
|
if (fabsq (__real__ x) > FLT128_MIN)
|
|
{
|
|
sinhrx = sinhq (__real__ x);
|
|
coshrx = coshq (__real__ x);
|
|
}
|
|
else
|
|
{
|
|
sinhrx = __real__ x;
|
|
coshrx = 1.0Q;
|
|
}
|
|
|
|
if (fabsq (sinhrx) > fabsq (cosix) * FLT128_EPSILON)
|
|
den = sinhrx * sinhrx + cosix * cosix;
|
|
else
|
|
den = cosix * cosix;
|
|
__real__ res = sinhrx * coshrx / den;
|
|
__imag__ res = sinix * cosix / den;
|
|
}
|
|
}
|
|
|
|
return res;
|
|
}
|