1/* mpfr_dim -- positive difference
2
3Copyright 2001, 2002, 2004, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
4Contributed by the AriC and Caramel projects, INRIA.
5
6This file is part of the GNU MPFR Library.
7
8The GNU MPFR Library is free software; you can redistribute it and/or modify
9it under the terms of the GNU Lesser General Public License as published by
10the Free Software Foundation; either version 3 of the License, or (at your
11option) any later version.
12
13The GNU MPFR Library is distributed in the hope that it will be useful, but
14WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
16License for more details.
17
18You should have received a copy of the GNU Lesser General Public License
19along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
20http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
2151 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
22
23#include "mpfr-impl.h"
24
25/* dim (x,y) is defined as:
26
27    x-y if x >  y
28    +0    if x <= y
29*/
30
31int
32mpfr_dim (mpfr_ptr z, mpfr_srcptr x, mpfr_srcptr y, mpfr_rnd_t rnd_mode)
33{
34  if (MPFR_IS_NAN(x) || MPFR_IS_NAN(y))
35    {
36      MPFR_SET_NAN(z);
37      MPFR_RET_NAN;
38    }
39
40  if (mpfr_cmp (x,y) > 0)
41    return mpfr_sub (z, x, y, rnd_mode);
42  else
43    {
44      MPFR_SET_ZERO(z);
45      MPFR_SET_POS(z);
46      MPFR_RET(0);
47    }
48}
49