1  /* Test for NaN that does not need libm.
       2     Copyright (C) 2007-2021 Free Software Foundation, Inc.
       3  
       4     This file is free software: you can redistribute it and/or modify
       5     it under the terms of the GNU Lesser General Public License as
       6     published by the Free Software Foundation; either version 2.1 of the
       7     License, or (at your option) any later version.
       8  
       9     This file 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 Public License for more details.
      13  
      14     You should have received a copy of the GNU Lesser General Public License
      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) || (__clang_major__ >= 4)
      21     /* GCC >= 4.0 and clang provide a type-generic built-in for isnan.
      22        GCC >= 4.0 also provides __builtin_isnanf, but clang doesn't.  */
      23  #  undef isnanf
      24  #  define isnanf(x) __builtin_isnan ((float)(x))
      25  # elif defined isnan
      26  #  undef isnanf
      27  #  define isnanf(x) isnan ((float)(x))
      28  # else
      29     /* Get declaration of isnanf(), if not declared in <math.h>.  */
      30  #  if defined __sgi
      31     /* We can't include <ieeefp.h>, because it conflicts with our definition of
      32        isnand.  Therefore declare isnanf separately.  */
      33  extern int isnanf (float x);
      34  #  endif
      35  # endif
      36  #else
      37  /* Test whether X is a NaN.  */
      38  # undef isnanf
      39  # define isnanf rpl_isnanf
      40  extern int isnanf (float x);
      41  #endif