tests/nan.h

   1 /* Macros for not-a-number.
   2    Copyright (C) 2007-2020 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 <https://www.gnu.org/licenses/>.  */
  16
  17
  18 /* IBM z/OS supports both hexadecimal and IEEE floating-point formats. The
  19    former does not support NaN and its isnan() implementation returns zero
  20    for all values.  */
  21 #if defined __MVS__ && defined __IBMC__ && !defined __BFP__
  22 # error "NaN is not supported with IBM's hexadecimal floating-point format; please re-compile with -qfloat=ieee"
  23 #endif
  24
  25 /* NaNf () returns a 'float' not-a-number.  */
  26
  27 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
  28    on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.
  29    PGI 16.10 complains.  */
  30 #if (defined __DECC || defined _MSC_VER \
  31      || (defined __MVS__ && defined __IBMC__)   \
  32      || defined __PGI)
  33 static float
  34 NaNf ()
  35 {
  36   static float zero = 0.0f;
  37   return zero / zero;
  38 }
  39 #else
  40 # define NaNf() (0.0f / 0.0f)
  41 #endif
  42
  43
  44 /* NaNd () returns a 'double' not-a-number.  */
  45
  46 /* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke
  47    on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.
  48    PGI 16.10 complains.  */
  49 #if (defined __DECC || defined _MSC_VER \
  50      || (defined __MVS__ && defined __IBMC__)   \
  51      || defined __PGI)
  52 static double
  53 NaNd ()
  54 {
  55   static double zero = 0.0;
  56   return zero / zero;
  57 }
  58 #else
  59 # define NaNd() (0.0 / 0.0)
  60 #endif
  61
  62
  63 /* NaNl () returns a 'long double' not-a-number.  */
  64
  65 /* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the
  66    runtime type conversion.
  67    The Microsoft MSVC 9 compiler chokes on the expression 0.0L / 0.0L.
  68    The IBM XL C compiler on z/OS complains.
  69    PGI 16.10 complains.  */
  70 #ifdef __sgi
  71 static long double NaNl ()
  72 {
  73   double zero = 0.0;
  74   return zero / zero;
  75 }
  76 #elif defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI
  77 static long double
  78 NaNl ()
  79 {
  80   static long double zero = 0.0L;
  81   return zero / zero;
  82 }
  83 #else
  84 # define NaNl() (0.0L / 0.0L)
  85 #endif