gl/tests/nan.h

   1 /* Macros for not-a-number.
   2    Copyright (C) 2007-2012 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation; either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17
  18 /* NaNf () returns a 'float' not-a-number.  */
  19
  20 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
  21    on the expression 0.0 / 0.0.  */
  22 #if defined __DECC || defined _MSC_VER
  23 static float
  24 NaNf ()
  25 {
  26   static float zero = 0.0f;
  27   return zero / zero;
  28 }
  29 #else
  30 # define NaNf() (0.0f / 0.0f)
  31 #endif
  32
  33
  34 /* NaNd () returns a 'double' not-a-number.  */
  35
  36 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
  37    on the expression 0.0 / 0.0.  */
  38 #if defined __DECC || defined _MSC_VER
  39 static double
  40 NaNd ()
  41 {
  42   static double zero = 0.0;
  43   return zero / zero;
  44 }
  45 #else
  46 # define NaNd() (0.0 / 0.0)
  47 #endif
  48
  49
  50 /* NaNl () returns a 'long double' not-a-number.  */
  51
  52 /* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the
  53    runtime type conversion.
  54    The Microsoft MSVC 9 compiler chokes on the expression 0.0L / 0.0L.  */
  55 #ifdef __sgi
  56 static long double NaNl ()
  57 {
  58   double zero = 0.0;
  59   return zero / zero;
  60 }
  61 #elif defined _MSC_VER
  62 static long double
  63 NaNl ()
  64 {
  65   static long double zero = 0.0L;
  66   return zero / zero;
  67 }
  68 #else
  69 # define NaNl() (0.0L / 0.0L)
  70 #endif