tests/test-nan-1.c

   1 /* Tests of quiet not-a-number.
   2    Copyright (C) 2023-2024 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 /* Written by Bruno Haible <bruno@clisp.org>, 2023.  */
  18
  19 #include <config.h>
  20
  21 /* Specification.  */
  22 #include "nan.h"
  23
  24 #if defined __GLIBC__ && defined __arm__ && defined __SOFTFP__
  25
  26 # include <stdio.h>
  27
  28 /* The arm software floating-point emulation (used e.g. on armv5) does not set
  29    the floating-point exception bits.  */
  30
  31 int
  32 main ()
  33 {
  34   fputs ("Skipping test: software floating-point emulation\n", stderr);
  35   return 77;
  36 }
  37
  38 #else
  39
  40 # include <fenv.h>
  41
  42 # include "macros.h"
  43
  44 float volatile resultf;
  45 double volatile resultd;
  46 long double volatile resultl;
  47
  48 int
  49 main ()
  50 {
  51   /* Fetch the NaN values before we start watching out for FE_INVALID
  52      exceptions, because the division 0.0 / 0.0 itself also raises an
  53      FE_INVALID exception.
  54      The use of 'volatile' prevents the compiler from doing constant-folding
  55      optimizations on these values.  An alternative, for GCC only, would be
  56      the command-line option '-fsignaling-nans'.  */
  57   float volatile nanf = NaNf ();
  58   double volatile nand = NaNd ();
  59   long double volatile nanl = NaNl ();
  60
  61   /* Check that the values are really quiet.  */
  62   {
  63     feclearexcept (FE_INVALID);
  64     resultf = nanf + 42.0f;
  65     ASSERT (!fetestexcept (FE_INVALID));
  66   }
  67   {
  68     feclearexcept (FE_INVALID);
  69     resultd = nand + 42.0;
  70     ASSERT (!fetestexcept (FE_INVALID));
  71   }
  72   {
  73     feclearexcept (FE_INVALID);
  74     resultl = nanl + 42.0L;
  75     ASSERT (!fetestexcept (FE_INVALID));
  76   }
  77
  78   return test_exit_status;
  79 }
  80
  81 #endif