view tests/test-ldexpl.c @ 9854:baba3b346ab2

Use macros NaNf, NaNd, NaNl instead of NAN.
author Bruno Haible <bruno@clisp.org>
date Wed, 02 Apr 2008 03:06:02 +0200
parents bbbbbf4cd1c5
children 0be6f1ab456d
line wrap: on
line source

/* Test of multiplying a 'long double' by a power of 2.
   Copyright (C) 2007 Free Software Foundation, Inc.

   This program is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* Written by Bruno Haible <bruno@clisp.org>, 2007.  */

#include <config.h>

#include <math.h>

#include <float.h>
#include <stdio.h>
#include <stdlib.h>

#include "fpucw.h"
#include "isnanl-nolibm.h"

#define ASSERT(expr) \
  do									     \
    {									     \
      if (!(expr))							     \
        {								     \
          fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
          abort ();							     \
        }								     \
    }									     \
  while (0)

int
main ()
{
  int i;
  long double x;
  long double y;
  DECL_LONG_DOUBLE_ROUNDING

  BEGIN_LONG_DOUBLE_ROUNDING ();

  { /* NaN.  */
    x = 0.0L / 0.0L;
    y = ldexpl (x, 0); ASSERT (isnanl (y));
    y = ldexpl (x, 5); ASSERT (isnanl (y));
    y = ldexpl (x, -5); ASSERT (isnanl (y));
  }

  { /* Positive infinity.  */
    x = 1.0L / 0.0L;
    y = ldexpl (x, 0); ASSERT (y == x);
    y = ldexpl (x, 5); ASSERT (y == x);
    y = ldexpl (x, -5); ASSERT (y == x);
  }

  { /* Negative infinity.  */
    x = -1.0L / 0.0L;
    y = ldexpl (x, 0); ASSERT (y == x);
    y = ldexpl (x, 5); ASSERT (y == x);
    y = ldexpl (x, -5); ASSERT (y == x);
  }

  { /* Positive zero.  */
    x = 0.0L;
    y = ldexpl (x, 0); ASSERT (y == x); ASSERT (!signbit (x));
    y = ldexpl (x, 5); ASSERT (y == x); ASSERT (!signbit (x));
    y = ldexpl (x, -5); ASSERT (y == x); ASSERT (!signbit (x));
  }

  { /* Negative zero.  */
    x = -0.0L;
    y = ldexpl (x, 0); ASSERT (y == x); ASSERT (signbit (x));
    y = ldexpl (x, 5); ASSERT (y == x); ASSERT (signbit (x));
    y = ldexpl (x, -5); ASSERT (y == x); ASSERT (signbit (x));
  }

  { /* Positive finite number.  */
    x = 1.73205L;
    y = ldexpl (x, 0); ASSERT (y == x);
    y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
    y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
  }

  { /* Negative finite number.  */
    x = -20.085536923187667742L;
    y = ldexpl (x, 0); ASSERT (y == x);
    y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
    y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
  }

  for (i = 1, x = 1.73205L; i <= LDBL_MAX_EXP; i++, x *= 2.0L)
    {
      y = ldexpl (x, 0); ASSERT (y == x);
      y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
      y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
    }
  for (i = 1, x = 1.73205L; i >= LDBL_MIN_EXP; i--, x *= 0.5L)
    {
      y = ldexpl (x, 0); ASSERT (y == x);
      y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
      if (i - 5 >= LDBL_MIN_EXP)
	{
	  y = ldexpl (x, -5); ASSERT (y == x * 0.03125L);
	}
    }
  for (; i >= LDBL_MIN_EXP - 100 && x > 0.0L; i--, x *= 0.5L)
    {
      y = ldexpl (x, 0); ASSERT (y == x);
      y = ldexpl (x, 5); ASSERT (y == x * 32.0L);
    }

  return 0;
}