libm/e_exp10.c

   1 /* Copyright (C) 1998-2015 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
   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    <http://www.gnu.org/licenses/>.  */
  18
  19 #include "math.h"
  20 #include "math_private.h"
  21 #include <float.h>
  22
  23 double __ieee754_exp10 (double arg)
  24 {
  25   if (isfinite (arg) && arg < DBL_MIN_10_EXP - DBL_DIG - 10)
  26     return DBL_MIN * DBL_MIN;
  27   else
  28     /* This is a very stupid and inprecise implementation.  It'll get
  29        replaced sometime (soon?).  */
  30     return __ieee754_exp (M_LN10 * arg);
  31 }