lib/isnanf-nolibm.h

   1 /* Test for NaN that does not need libm.
   2    Copyright (C) 2007-2024 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_ISNANF_IN_LIBC.  */
  18 #if !_GL_CONFIG_H_INCLUDED
  19  #error "Please include config.h first."
  20 #endif
  21
  22 #if HAVE_ISNANF_IN_LIBC
  23 /* Get declaration of isnan macro or (older) isnanf 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_isnanf, but clang doesn't.  */
  28 #  undef isnanf
  29 #  define isnanf(x) __builtin_isnan ((float)(x))
  30 # elif defined isnan
  31 #  undef isnanf
  32 #  define isnanf(x) isnan ((float)(x))
  33 # else
  34    /* Get declaration of isnanf(), if not declared in <math.h>.  */
  35 #  if defined __sgi
  36    /* We can't include <ieeefp.h>, because it conflicts with our definition of
  37       isnand.  Therefore declare isnanf separately.  */
  38 extern int isnanf (float x);
  39 #  endif
  40 # endif
  41 #else
  42 /* Test whether X is a NaN.  */
  43 # undef isnanf
  44 # define isnanf rpl_isnanf
  45 extern int isnanf (float x);
  46 #endif