math/s_cproj.c

   1 /* Compute projection of complex double value to Riemann sphere.
   2    Copyright (C) 1997-2015 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <complex.h>
  21 #include <math.h>
  22 #include <math_private.h>
  23
  24
  25 __complex__ double
  26 __cproj (__complex__ double x)
  27 {
  28   if (__isinf_ns (__real__ x) || __isinf_ns (__imag__ x))
  29     {
  30       __complex__ double res;
  31
  32       __real__ res = INFINITY;
  33       __imag__ res = __copysign (0.0, __imag__ x);
  34
  35       return res;
  36     }
  37
  38   return x;
  39 }
  40 weak_alias (__cproj, cproj)
  41 #ifdef NO_LONG_DOUBLE
  42 strong_alias (__cproj, __cprojl)
  43 weak_alias (__cproj, cprojl)
  44 #endif