tests/test-trunc-ieee.c

   1 /* Test of rounding towards zero.
   2    Copyright (C) 2010-2018 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 #include <config.h>
  18
  19 #include <math.h>
  20
  21 #include "isnand-nolibm.h"
  22 #include "minus-zero.h"
  23 #include "infinity.h"
  24 #include "nan.h"
  25 #include "macros.h"
  26
  27 int
  28 main ()
  29 {
  30   /* See IEEE 754, section 6.3:
  31        "the sign of the result of the round floating-point number to
  32         integral value operation is the sign of the operand. These rules
  33         shall apply even when operands or results are zero or infinite."  */
  34
  35   /* Zero.  */
  36   ASSERT (!signbit (trunc (0.0)));
  37   ASSERT (!!signbit (trunc (minus_zerod)) == !!signbit (minus_zerod));
  38   /* Positive numbers.  */
  39   ASSERT (!signbit (trunc (0.3)));
  40   ASSERT (!signbit (trunc (0.7)));
  41   /* Negative numbers.  */
  42   ASSERT (!!signbit (trunc (-0.3)) == !!signbit (minus_zerod));
  43   ASSERT (!!signbit (trunc (-0.7)) == !!signbit (minus_zerod));
  44
  45   /* [MX] shaded specification in POSIX.  */
  46
  47   /* NaN.  */
  48   ASSERT (isnand (trunc (NaNd ())));
  49   /* Infinity.  */
  50   ASSERT (trunc (Infinityd ()) == Infinityd ());
  51   ASSERT (trunc (- Infinityd ()) == - Infinityd ());
  52
  53   return 0;
  54 }