libquadmath/math/fdimq.c

   1 /* Return positive difference between arguments.
   2    Copyright (C) 1997-2018 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include "quadmath-imp.h"
  21
  22 __float128
  23 fdimq (__float128 x, __float128 y)
  24 {
  25   if (__builtin_islessequal (x, y))
  26     return 0;
  27
  28   __float128 r = math_narrow_eval (x - y);
  29   if (isinfq (r) && !isinfq (x) && !isinfq (y))
  30     errno = ERANGE;
  31
  32   return r;
  33 }