1  /* Test for NaN that does not need libm.
       2     Copyright (C) 2007-2023 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  /* This file uses HAVE_ISNANL_IN_LIBC.  */
      18  #if !_GL_CONFIG_H_INCLUDED
      19   #error "Please include config.h first."
      20  #endif
      21  
      22  #if HAVE_ISNANL_IN_LIBC
      23  /* Get declaration of isnan macro or (older) isnanl function.  */
      24  # include <math.h>
      25  # if (__GNUC__ >= 4) || (__clang_major__ >= 4)
      26     /* GCC >= 4.0 and clang provide a type-generic built-in for isnan.
      27        GCC >= 4.0 also provides __builtin_isnanl, but clang doesn't.  */
      28  #  undef isnanl
      29  #  define isnanl(x) __builtin_isnan ((long double)(x))
      30  # elif defined isnan
      31  #  undef isnanl
      32  #  define isnanl(x) isnan ((long double)(x))
      33  # endif
      34  #else
      35  /* Test whether X is a NaN.  */
      36  # undef isnanl
      37  # define isnanl rpl_isnanl
      38  extern int isnanl (long double x);
      39  #endif