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/* Test of isnan() substitute.
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 2, 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, write to the Free Software Foundation,
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
/* Written by Bruno Haible <bruno@clisp.org>, 2007. */
#include <config.h>
#include "isnan.h"
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#define ASSERT(expr) \
do \
{ \
if (!(expr)) \
{ \
fprintf (stderr, "%s:%d: assertion failed\n", __FILE__, __LINE__); \
abort (); \
} \
} \
while (0)
/* The Compaq (ex-DEC) C 6.4 compiler chokes on the expression 0.0 / 0.0. */
#ifdef __DECC
static double
NaN ()
{
static double zero = 0.0;
return zero / zero;
}
#else
# define NaN() (0.0 / 0.0)
#endif
int
main ()
{
/* Finite values. */
ASSERT (!isnan (3.141));
ASSERT (!isnan (3.141e30));
ASSERT (!isnan (3.141e-30));
ASSERT (!isnan (-2.718));
ASSERT (!isnan (-2.718e30));
ASSERT (!isnan (-2.718e-30));
/* Infinite values. */
ASSERT (!isnan (1.0 / 0.0));
ASSERT (!isnan (-1.0 / 0.0));
/* Quiet NaN. */
ASSERT (isnan (NaN ()));
#if defined DBL_EXPBIT0_WORD && defined DBL_EXPBIT0_BIT
/* Signalling NaN. */
{
#define NWORDS \
((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
typedef union { double value; unsigned int word[NWORDS]; } memory_double;
memory_double m;
m.value = NaN ();
# if DBL_EXPBIT0_BIT > 0
m.word[DBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (DBL_EXPBIT0_BIT - 1);
# else
m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
# endif
m.word[DBL_EXPBIT0_WORD + (DBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
|= (unsigned int) 1 << DBL_EXPBIT0_BIT;
ASSERT (isnan (m.value));
}
#endif
return 0;
}
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