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_ISNANL_IN_LIBC
      18  /* Get declaration of isnan macro or (older) isnanl 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_isnanl, but clang doesn't.  */
      23  #  undef isnanl
      24  #  define isnanl(x) __builtin_isnan ((long double)(x))
      25  # elif defined isnan
      26  #  undef isnanl
      27  #  define isnanl(x) isnan ((long double)(x))
      28  # endif
      29  #else
      30  /* Test whether X is a NaN.  */
      31  # undef isnanl
      32  # define isnanl rpl_isnanl
      33  extern int isnanl (long double x);
      34  #endif