tests/test-frexp-ieee.h

   1 /* Test of splitting a double into fraction and mantissa.
   2    Copyright (C) 2012-2020 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 static void
  18 test_function (void)
  19 {
  20   /* [MX] shaded specification in POSIX.  */
  21
  22   /* NaN.  */
  23   {
  24     int exp = -9999;
  25     DOUBLE mantissa;
  26     mantissa = FREXP (NAN, &exp);
  27     ASSERT (ISNAN (mantissa));
  28   }
  29
  30   /* Signed zero.  */
  31   {
  32     int exp = -9999;
  33     DOUBLE mantissa;
  34     mantissa = FREXP (L_(0.0), &exp);
  35     ASSERT (mantissa == L_(0.0));
  36     ASSERT (!signbit (mantissa));
  37     ASSERT (exp == 0);
  38   }
  39   {
  40     int exp = -9999;
  41     DOUBLE mantissa;
  42     mantissa = FREXP (MINUS_ZERO, &exp);
  43     ASSERT (mantissa == L_(0.0));
  44     ASSERT (!!signbit (mantissa) == !!signbit (MINUS_ZERO));
  45     ASSERT (exp == 0);
  46   }
  47
  48   /* Infinity.  */
  49   {
  50     int exp = -9999;
  51     DOUBLE mantissa;
  52     mantissa = FREXP (INFINITY, &exp);
  53     ASSERT (mantissa == INFINITY);
  54   }
  55   {
  56     int exp = -9999;
  57     DOUBLE mantissa;
  58     mantissa = FREXP (- INFINITY, &exp);
  59     ASSERT (mantissa == - INFINITY);
  60   }
  61 }