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 Public License 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 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_ISNAND_IN_LIBC
      18  /* Get declaration of isnan macro.  */
      19  # include <gnulib_math.h>
      20  # if __GNUC__ >= 4
      21     /* GCC 4.0 and newer provides three built-ins for isnan.  */
      22  #  undef isnand
      23  #  define isnand(x) __builtin_isnan ((double)(x))
      24  # else
      25  #  undef isnand
      26  #  define isnand(x) isnan ((double)(x))
      27  # endif
      28  #else
      29  /* Test whether X is a NaN.  */
      30  # undef isnand
      31  # define isnand rpl_isnand
      32  extern int isnand (double x);
      33  #endif