gnulib/tests/test-isnanl.h

/* Test of isnanl() substitute.
   Copyright (C) 2007-2020 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 <https://www.gnu.org/licenses/>.  */

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

#include <float.h>
#include <limits.h>

#include "minus-zero.h"
#include "infinity.h"
#include "nan.h"
#include "macros.h"

int
main ()
{
  #define NWORDS \
    ((sizeof (long double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
  typedef union { unsigned int word[NWORDS]; long double value; }
          memory_long_double;

  /* Finite values.  */
  ASSERT (!isnanl (3.141L));
  ASSERT (!isnanl (3.141e30L));
  ASSERT (!isnanl (3.141e-30L));
  ASSERT (!isnanl (-2.718L));
  ASSERT (!isnanl (-2.718e30L));
  ASSERT (!isnanl (-2.718e-30L));
  ASSERT (!isnanl (0.0L));
  ASSERT (!isnanl (minus_zerol));
  /* Infinite values.  */
  ASSERT (!isnanl (Infinityl ()));
  ASSERT (!isnanl (- Infinityl ()));
  /* Quiet NaN.  */
  ASSERT (isnanl (NaNl ()));

#if defined LDBL_EXPBIT0_WORD && defined LDBL_EXPBIT0_BIT
  /* A bit pattern that is different from a Quiet NaN.  With a bit of luck,
     it's a Signalling NaN.  */
  {
#if defined __powerpc__ && LDBL_MANT_DIG == 106
    /* This is PowerPC "double double", a pair of two doubles.  Inf and Nan are
       represented as the corresponding 64-bit IEEE values in the first double;
       the second is ignored.  Manipulate only the first double.  */
    #undef NWORDS
    #define NWORDS \
      ((sizeof (double) + sizeof (unsigned int) - 1) / sizeof (unsigned int))
#endif

    memory_long_double m;
    m.value = NaNl ();
# if LDBL_EXPBIT0_BIT > 0
    m.word[LDBL_EXPBIT0_WORD] ^= (unsigned int) 1 << (LDBL_EXPBIT0_BIT - 1);
# else
    m.word[LDBL_EXPBIT0_WORD + (LDBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
      ^= (unsigned int) 1 << (sizeof (unsigned int) * CHAR_BIT - 1);
# endif
    m.word[LDBL_EXPBIT0_WORD + (LDBL_EXPBIT0_WORD < NWORDS / 2 ? 1 : - 1)]
      |= (unsigned int) 1 << LDBL_EXPBIT0_BIT;
    ASSERT (isnanl (m.value));
  }
#endif

#if ((defined __ia64 && LDBL_MANT_DIG == 64) || (defined __x86_64__ || defined __amd64__) || (defined __i386 || defined __i386__ || defined _I386 || defined _M_IX86 || defined _X86_)) && !HAVE_SAME_LONG_DOUBLE_AS_DOUBLE
/* Representation of an 80-bit 'long double' as an initializer for a sequence
   of 'unsigned int' words.  */
# ifdef WORDS_BIGENDIAN
#  define LDBL80_WORDS(exponent,manthi,mantlo) \
     { ((unsigned int) (exponent) << 16) | ((unsigned int) (manthi) >> 16), \
       ((unsigned int) (manthi) << 16) | ((unsigned int) (mantlo) >> 16),   \
       (unsigned int) (mantlo) << 16                                        \
     }
# else
#  define LDBL80_WORDS(exponent,manthi,mantlo) \
     { mantlo, manthi, exponent }
# endif
  { /* Quiet NaN.  */
    static memory_long_double x =
      { LDBL80_WORDS (0xFFFF, 0xC3333333, 0x00000000) };
    ASSERT (isnanl (x.value));
  }
  {
    /* Signalling NaN.  */
    static memory_long_double x =
      { LDBL80_WORDS (0xFFFF, 0x83333333, 0x00000000) };
    ASSERT (isnanl (x.value));
  }
  /* isnanl should return something for noncanonical values.  */
  { /* Pseudo-NaN.  */
    static memory_long_double x =
      { LDBL80_WORDS (0xFFFF, 0x40000001, 0x00000000) };
    ASSERT (isnanl (x.value) || !isnanl (x.value));
  }
  { /* Pseudo-Infinity.  */
    static memory_long_double x =
      { LDBL80_WORDS (0xFFFF, 0x00000000, 0x00000000) };
    ASSERT (isnanl (x.value) || !isnanl (x.value));
  }
  { /* Pseudo-Zero.  */
    static memory_long_double x =
      { LDBL80_WORDS (0x4004, 0x00000000, 0x00000000) };
    ASSERT (isnanl (x.value) || !isnanl (x.value));
  }
  { /* Unnormalized number.  */
    static memory_long_double x =
      { LDBL80_WORDS (0x4000, 0x63333333, 0x00000000) };
    ASSERT (isnanl (x.value) || !isnanl (x.value));
  }
  { /* Pseudo-Denormal.  */
    static memory_long_double x =
      { LDBL80_WORDS (0x0000, 0x83333333, 0x00000000) };
    ASSERT (isnanl (x.value) || !isnanl (x.value));
  }
#endif

  return 0;
}