1  /* Test for NaN that does not need libm.
       2     Copyright (C) 2007-2019 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 Lesser General PublicLicense as published by
       6     the Free Software Foundation; either version 2.1 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 Lesser General PublicLicense for more details.
      13  
      14     You should have received a copy of the GNU Lesser General PublicLicense
      15     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
      16  
      17  #if HAVE_ISNANF_IN_LIBC
      18  /* Get declaration of isnan macro or (older) isnanf function.  */
      19  # include <math.h>
      20  # if __GNUC__ >= 4
      21     /* GCC 4.0 and newer provides three built-ins for isnan.  */
      22  #  undef isnanf
      23  #  define isnanf(x) __builtin_isnanf ((float)(x))
      24  # elif defined isnan
      25  #  undef isnanf
      26  #  define isnanf(x) isnan ((float)(x))
      27  # else
      28     /* Get declaration of isnanf(), if not declared in <math.h>.  */
      29  #  if defined __sgi
      30     /* We can't include <ieeefp.h>, because it conflicts with our definition of
      31        isnand.  Therefore declare isnanf separately.  */
      32  extern int isnanf (float x);
      33  #  endif
      34  # endif
      35  #else
      36  /* Test whether X is a NaN.  */
      37  # undef isnanf
      38  # define isnanf rpl_isnanf
      39  extern int isnanf (float x);
      40  #endif