143 lines
3.8 KiB
C
143 lines
3.8 KiB
C
/* Return arc hyperbole tangent for float value.
|
|
Copyright (C) 1997-2013 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 <math.h>
|
|
#include <math_private.h>
|
|
#include <float.h>
|
|
|
|
__complex__ float
|
|
__catanhf (__complex__ float x)
|
|
{
|
|
__complex__ float res;
|
|
int rcls = fpclassify (__real__ x);
|
|
int icls = fpclassify (__imag__ x);
|
|
|
|
if (__builtin_expect (rcls <= FP_INFINITE || icls <= FP_INFINITE, 0))
|
|
{
|
|
if (icls == FP_INFINITE)
|
|
{
|
|
__real__ res = __copysignf (0.0, __real__ x);
|
|
__imag__ res = __copysignf (M_PI_2, __imag__ x);
|
|
}
|
|
else if (rcls == FP_INFINITE || rcls == FP_ZERO)
|
|
{
|
|
__real__ res = __copysignf (0.0, __real__ x);
|
|
if (icls >= FP_ZERO)
|
|
__imag__ res = __copysignf (M_PI_2, __imag__ x);
|
|
else
|
|
__imag__ res = __nanf ("");
|
|
}
|
|
else
|
|
{
|
|
__real__ res = __nanf ("");
|
|
__imag__ res = __nanf ("");
|
|
}
|
|
}
|
|
else if (__builtin_expect (rcls == FP_ZERO && icls == FP_ZERO, 0))
|
|
{
|
|
res = x;
|
|
}
|
|
else
|
|
{
|
|
if (fabsf (__real__ x) >= 16.0f / FLT_EPSILON
|
|
|| fabsf (__imag__ x) >= 16.0f / FLT_EPSILON)
|
|
{
|
|
__imag__ res = __copysignf ((float) M_PI_2, __imag__ x);
|
|
if (fabsf (__imag__ x) <= 1.0f)
|
|
__real__ res = 1.0f / __real__ x;
|
|
else if (fabsf (__real__ x) <= 1.0f)
|
|
__real__ res = __real__ x / __imag__ x / __imag__ x;
|
|
else
|
|
{
|
|
float h = __ieee754_hypotf (__real__ x / 2.0f,
|
|
__imag__ x / 2.0f);
|
|
__real__ res = __real__ x / h / h / 4.0f;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (fabsf (__real__ x) == 1.0f
|
|
&& fabsf (__imag__ x) < FLT_EPSILON * FLT_EPSILON)
|
|
__real__ res = (__copysignf (0.5f, __real__ x)
|
|
* ((float) M_LN2
|
|
- __ieee754_logf (fabsf (__imag__ x))));
|
|
else
|
|
{
|
|
float i2 = 0.0f;
|
|
if (fabsf (__imag__ x) >= FLT_EPSILON * FLT_EPSILON)
|
|
i2 = __imag__ x * __imag__ x;
|
|
|
|
float num = 1.0f + __real__ x;
|
|
num = i2 + num * num;
|
|
|
|
float den = 1.0f - __real__ x;
|
|
den = i2 + den * den;
|
|
|
|
float f = num / den;
|
|
if (f < 0.5f)
|
|
__real__ res = 0.25f * __ieee754_logf (f);
|
|
else
|
|
{
|
|
num = 4.0f * __real__ x;
|
|
__real__ res = 0.25f * __log1pf (num / den);
|
|
}
|
|
}
|
|
|
|
float absx, absy, den;
|
|
|
|
absx = fabsf (__real__ x);
|
|
absy = fabsf (__imag__ x);
|
|
if (absx < absy)
|
|
{
|
|
float t = absx;
|
|
absx = absy;
|
|
absy = t;
|
|
}
|
|
|
|
if (absy < FLT_EPSILON / 2.0f)
|
|
den = (1.0f - absx) * (1.0f + absx);
|
|
else if (absx >= 1.0f)
|
|
den = (1.0f - absx) * (1.0f + absx) - absy * absy;
|
|
else if (absx >= 0.75f || absy >= 0.5f)
|
|
den = -__x2y2m1f (absx, absy);
|
|
else
|
|
den = (1.0f - absx) * (1.0f + absx) - absy * absy;
|
|
|
|
__imag__ res = 0.5f * __ieee754_atan2f (2.0f * __imag__ x, den);
|
|
}
|
|
|
|
if (fabsf (__real__ res) < FLT_MIN)
|
|
{
|
|
volatile float force_underflow = __real__ res * __real__ res;
|
|
(void) force_underflow;
|
|
}
|
|
if (fabsf (__imag__ res) < FLT_MIN)
|
|
{
|
|
volatile float force_underflow = __imag__ res * __imag__ res;
|
|
(void) force_underflow;
|
|
}
|
|
}
|
|
|
|
return res;
|
|
}
|
|
#ifndef __catanhf
|
|
weak_alias (__catanhf, catanhf)
|
|
#endif
|