mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-30 16:50:07 +00:00
85 lines
2.3 KiB
C
85 lines
2.3 KiB
C
/* Return arc hyperbole tangent for double 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>
|
|
|
|
#include "math_private.h"
|
|
|
|
|
|
__complex__ double
|
|
__catanh (__complex__ double x)
|
|
{
|
|
__complex__ double res;
|
|
int rcls = fpclassify (__real__ x);
|
|
int icls = fpclassify (__imag__ x);
|
|
|
|
if (rcls <= FP_INFINITE || icls <= FP_INFINITE)
|
|
{
|
|
if (icls == FP_INFINITE)
|
|
{
|
|
__real__ res = __copysign (0.0, __real__ x);
|
|
__imag__ res = __copysign (M_PI_2, __imag__ x);
|
|
}
|
|
else if (rcls == FP_INFINITE || rcls == FP_ZERO)
|
|
{
|
|
__real__ res = __copysign (0.0, __real__ x);
|
|
if (icls >= FP_ZERO)
|
|
__imag__ res = __copysign (M_PI_2, __imag__ x);
|
|
else
|
|
__imag__ res = __nan ("");
|
|
}
|
|
else
|
|
{
|
|
__real__ res = __nan ("");
|
|
__imag__ res = __nan ("");
|
|
}
|
|
}
|
|
else if (rcls == FP_ZERO && icls == FP_ZERO)
|
|
{
|
|
res = x;
|
|
}
|
|
else
|
|
{
|
|
double i2, num, den;
|
|
|
|
i2 = __imag__ x * __imag__ x;
|
|
|
|
num = 1.0 + __real__ x;
|
|
num = i2 + num * num;
|
|
|
|
den = 1.0 - __real__ x;
|
|
den = i2 + den * den;
|
|
|
|
__real__ res = 0.25 * (__ieee754_log (num) - __ieee754_log (den));
|
|
|
|
den = 1 - __real__ x * __real__ x - i2;
|
|
|
|
__imag__ res = 0.5 * __ieee754_atan2 (2.0 * __imag__ x, den);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
weak_alias (__catanh, catanh)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__catanh, __catanhl)
|
|
weak_alias (__catanh, catanhl)
|
|
#endif
|