mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 21:10:07 +00:00
89 lines
2.4 KiB
C
89 lines
2.4 KiB
C
/* Return arc tangent of complex double value.
|
|
Copyright (C) 1997, 2011 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, 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
|
|
__catan (__complex__ double x)
|
|
{
|
|
__complex__ double res;
|
|
int rcls = fpclassify (__real__ x);
|
|
int icls = fpclassify (__imag__ x);
|
|
|
|
if (__builtin_expect (rcls <= FP_INFINITE || icls <= FP_INFINITE, 0))
|
|
{
|
|
if (rcls == FP_INFINITE)
|
|
{
|
|
__real__ res = __copysign (M_PI_2, __real__ x);
|
|
__imag__ res = __copysign (0.0, __imag__ x);
|
|
}
|
|
else if (icls == FP_INFINITE)
|
|
{
|
|
if (rcls >= FP_ZERO)
|
|
__real__ res = __copysign (M_PI_2, __real__ x);
|
|
else
|
|
__real__ res = __nan ("");
|
|
__imag__ res = __copysign (0.0, __imag__ x);
|
|
}
|
|
else if (icls == FP_ZERO || icls == FP_INFINITE)
|
|
{
|
|
__real__ res = __nan ("");
|
|
__imag__ res = __copysign (0.0, __imag__ x);
|
|
}
|
|
else
|
|
{
|
|
__real__ res = __nan ("");
|
|
__imag__ res = __nan ("");
|
|
}
|
|
}
|
|
else if (__builtin_expect (rcls == FP_ZERO && icls == FP_ZERO, 0))
|
|
{
|
|
res = x;
|
|
}
|
|
else
|
|
{
|
|
double r2, num, den;
|
|
|
|
r2 = __real__ x * __real__ x;
|
|
|
|
den = 1 - r2 - __imag__ x * __imag__ x;
|
|
|
|
__real__ res = 0.5 * __ieee754_atan2 (2.0 * __real__ x, den);
|
|
|
|
num = __imag__ x + 1.0;
|
|
num = r2 + num * num;
|
|
|
|
den = __imag__ x - 1.0;
|
|
den = r2 + den * den;
|
|
|
|
__imag__ res = 0.25 * __ieee754_log (num / den);
|
|
}
|
|
|
|
return res;
|
|
}
|
|
weak_alias (__catan, catan)
|
|
#ifdef NO_LONG_DOUBLE
|
|
strong_alias (__catan, __catanl)
|
|
weak_alias (__catan, catanl)
|
|
#endif
|