sysdeps/powerpc/fpu/s_isnan.c

   1 /* Return 1 if argument is a NaN, else 0.
   2    Copyright (C) 1997, 2000, 2002 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /* Ugly kludge to avoid declarations.  */
  21 #define __isnanf __Xisnanf
  22 #define isnanf Xisnanf
  23
  24 #include "math.h"
  25 #include <fenv_libc.h>
  26
  27 #undef __isnanf
  28 #undef isnanf
  29
  30 int
  31 __isnan (x)
  32      double x;
  33 {
  34   fenv_t savedstate;
  35   int result;
  36   savedstate = fegetenv_register ();
  37   reset_fpscr_bit (FPSCR_VE);
  38   result = !(x == x);
  39   fesetenv_register (savedstate);
  40   return result;
  41 }
  42 hidden_def (__isnan)
  43 weak_alias (__isnan, isnan)
  44
  45 /* It turns out that the 'double' version will also always work for
  46    single-precision.  */
  47 strong_alias (__isnan, __isnanf)
  48 hidden_def (__isnanf)
  49 weak_alias (__isnanf, isnanf)
  50
  51 #ifdef NO_LONG_DOUBLE
  52 strong_alias (__isnan, __isnanl)
  53 weak_alias (__isnan, isnanl)
  54 #endif