/* Macros for not-a-number.

   Copyright (C) 2007-2018 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/>.  */

/* IBM z/OS supports both hexadecimal and IEEE floating-point formats. The

   former does not support NaN and its isnan() implementation returns zero

   for all values.  */

#if defined __MVS__ && defined __IBMC__ && !defined __BFP__

# error "NaN is not supported with IBM's hexadecimal floating-point format; please re-compile with -qfloat=ieee"

#endif

/* NaNf () returns a 'float' not-a-number.  */

/* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke

   on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.

   PGI 16.10 complains.  */

#if (defined __DECC || defined _MSC_VER \

     || (defined __MVS__ && defined __IBMC__)   \

     || defined __PGI)

static float

NaNf ()

{

  static float zero = 0.0f;

  return zero / zero;

}

#else

# define NaNf() (0.0f / 0.0f)

#endif

/* NaNd () returns a 'double' not-a-number.  */

/* The Compaq (ex-DEC) C 6.4 compiler and the Microsoft MSVC 9 compiler choke

   on the expression 0.0 / 0.0.  The IBM XL C compiler on z/OS complains.

   PGI 16.10 complains.  */

#if (defined __DECC || defined _MSC_VER \

     || (defined __MVS__ && defined __IBMC__)   \

     || defined __PGI)

static double

NaNd ()

{

  static double zero = 0.0;

  return zero / zero;

}

#else

# define NaNd() (0.0 / 0.0)

#endif

/* NaNl () returns a 'long double' not-a-number.  */

/* On Irix 6.5, gcc 3.4.3 can't compute compile-time NaN, and needs the

   runtime type conversion.

   The Microsoft MSVC 9 compiler chokes on the expression 0.0L / 0.0L.

   The IBM XL C compiler on z/OS complains.

   PGI 16.10 complains.  */

#ifdef __sgi

static long double NaNl ()

{

  double zero = 0.0;

  return zero / zero;

}

#elif defined _MSC_VER || (defined __MVS__ && defined __IBMC__) || defined __PGI

static long double

NaNl ()

{

  static long double zero = 0.0L;

  return zero / zero;

}

#else

# define NaNl() (0.0L / 0.0L)

#endif