math/w_ilogb_template.c

   1 /* Wrapper to set errno for ilogb.
   2    Copyright (C) 2012-2021 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 #include <math.h>
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <math_private.h>
  23 #include <fenv.h>
  24
  25 /* wrapper ilogb */
  26 int
  27 M_DECL_FUNC (__ilogb) (FLOAT x)
  28 {
  29   int r = M_SUF (__ieee754_ilogb) (x);
  30   if (__builtin_expect (r == FP_ILOGB0, 0)
  31       || __builtin_expect (r == FP_ILOGBNAN, 0)
  32       || __builtin_expect (r == INT_MAX, 0))
  33     {
  34       __set_errno (EDOM);
  35       __feraiseexcept (FE_INVALID);
  36     }
  37   return r;
  38 }
  39 declare_mgen_alias (__ilogb, ilogb)