tests/test-floorf-ieee.c

   1 /* Test of rounding towards negative infinity.
   2    Copyright (C) 2010-2024 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 #include <config.h>
  18
  19 #include <math.h>
  20
  21 #include "isnanf-nolibm.h"
  22 #include "minus-zero.h"
  23 #include "infinity.h"
  24 #include "nan.h"
  25 #include "macros.h"
  26
  27 /* If IEEE compliance was not requested, the ICC compiler inlines its
  28    own floorf assembly that turns -0.0f to 0.0f; but that is a correct
  29    result when IEEE is not enforced.  To avoid spurious failure, we
  30    have to provide this dummy function in order to outsmart ICC's
  31    inlining, and call our floorf through a function pointer.  */
  32 static float
  33 dummy (float f)
  34 {
  35   return 0;
  36 }
  37
  38 int
  39 main (int argc, _GL_UNUSED char **argv)
  40 {
  41   float (* volatile my_floorf) (float) = argc ? floorf : dummy;
  42
  43   /* See IEEE 754, section 6.3:
  44        "the sign of the result of the round floating-point number to
  45         integral value operation is the sign of the operand. These rules
  46         shall apply even when operands or results are zero or infinite."  */
  47
  48   /* Zero.  */
  49   ASSERT (!signbit (my_floorf (0.0f)));
  50   ASSERT (!!signbit (my_floorf (minus_zerof)) == !!signbit (minus_zerof));
  51   /* Positive numbers.  */
  52   ASSERT (!signbit (my_floorf (0.3f)));
  53   ASSERT (!signbit (my_floorf (0.7f)));
  54   /* Negative numbers.  */
  55   ASSERT (!!signbit (my_floorf (-0.3f)) == !!signbit (minus_zerof));
  56   ASSERT (!!signbit (my_floorf (-0.7f)) == !!signbit (minus_zerof));
  57
  58   /* [MX] shaded specification in POSIX.  */
  59
  60   /* NaN.  */
  61   ASSERT (isnanf (floorf (NaNf ())));
  62   /* Infinity.  */
  63   ASSERT (floorf (Infinityf ()) == Infinityf ());
  64   ASSERT (floorf (- Infinityf ()) == - Infinityf ());
  65
  66   return test_exit_status;
  67 }