stdlib/tst-tininess.c

   1 /* Test that tininess.h is correct for this architecture.
   2    Copyright (C) 2012-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <fenv.h>
  20 #include <float.h>
  21 #include <stdio.h>
  22 #include <tininess.h>
  23
  24 volatile float a = 0x1.fffp-126;
  25 volatile float b = 0x1.0008p-1;
  26 volatile float c;
  27 volatile float m = FLT_MIN;
  28 volatile float mm;
  29
  30 static int
  31 do_test (void)
  32 {
  33   int result = 0;
  34 #ifdef FE_UNDERFLOW
  35   feclearexcept (FE_ALL_EXCEPT);
  36   mm = m * m;
  37   if (!fetestexcept (FE_UNDERFLOW))
  38     {
  39       puts ("underflow exception not supported at runtime, cannot test");
  40       return 0;
  41     }
  42   feclearexcept (FE_ALL_EXCEPT);
  43   c = a * b;
  44   if (fetestexcept (FE_UNDERFLOW))
  45     {
  46       if (TININESS_AFTER_ROUNDING)
  47         {
  48           puts ("tininess.h says after rounding, "
  49                 "but detected before rounding");
  50           result = 1;
  51         }
  52     }
  53   else
  54     {
  55       if (!TININESS_AFTER_ROUNDING)
  56         {
  57           puts ("tininess.h says before rounding, "
  58                 "but detected after rounding");
  59           result = 1;
  60         }
  61     }
  62 #else
  63   puts ("underflow exception not supported at compile time, cannot test");
  64 #endif
  65   return result;
  66 }
  67
  68 #define TEST_FUNCTION do_test ()
  69 #include "../test-skeleton.c"