sysdeps/alpha/fpu/s_isnan.c

   1 /* Return 1 if argument is a NaN, else 0.
   2    Copyright (C) 2007-2023 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, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 /* Ugly kludge to avoid declarations.  */
  20 #define __isnanf        not___isnanf
  21 #define isnanf          not_isnanf
  22 #define __GI___isnanf   not__GI___isnanf
  23
  24 #include <math.h>
  25 #include <math_private.h>
  26 #include <math_ldbl_opt.h>
  27
  28 #undef __isnanf
  29 #undef isnanf
  30 #undef __GI___isnanf
  31
  32 int
  33 __isnan (double x)
  34 {
  35   uint64_t ix;
  36   EXTRACT_WORDS64 (ix, x);
  37   return ix * 2 > 0xffe0000000000000ul;
  38 }
  39
  40 hidden_def (__isnan)
  41 weak_alias (__isnan, isnan)
  42
  43 /* It turns out that the 'double' version will also always work for
  44    single-precision.  */
  45 strong_alias (__isnan, __isnanf)
  46 weak_alias (__isnan, isnanf)
  47
  48 /* ??? GCC 4.8 fails to look through chains of aliases with asm names
  49    attached.  Work around this for now.  */
  50 hidden_ver (__isnan, __isnanf)
  51
  52 #ifdef NO_LONG_DOUBLE
  53 strong_alias (__isnan, __isnanl)
  54 weak_alias (__isnan, isnanl)
  55 #endif
  56 #if LONG_DOUBLE_COMPAT(libc, GLIBC_2_0)
  57 compat_symbol (libc, __isnan, __isnanl, GLIBC_2_0);
  58 compat_symbol (libc, isnan, isnanl, GLIBC_2_0);
  59 #endif