aboutsummaryrefslogtreecommitdiff
blob: 83809eea0e3519a72f998d9b779b802a5bcc61dd (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
/* Compute projection of complex float value to Riemann sphere.
   Copyright (C) 1997, 1999 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>


__complex__ float
__cprojf (__complex__ float x)
{
  __complex__ float res;

  if (isnan (__real__ x) && isnan (__imag__ x))
    return x;
  else if (!isfinite (__real__ x) || !isfinite (__imag__ x))
    {
      __real__ res = INFINITY;
      __imag__ res = __copysignf (0.0, __imag__ x);
    }
  else
    {
      float den = __real__ x * __real__ x + __imag__ x * __imag__ x + 1.0;

      __real__ res = (2.0 * __real__ x) / den;
      __imag__ res = (2.0 * __imag__ x) / den;
    }

  return res;
}
weak_alias (__cprojf, cprojf)