/* mpfr_dim -- dim of x, y  

Copyright 2001, 2002 Free Software Foundation.

This file is part of the MPFR Library.

The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.

The MPFR Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the MPFR Library; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */

#include "gmp.h"
#include "gmp-impl.h"
#include "mpfr.h"
#include "mpfr-impl.h"

 /* The computation of z=dim(x,y)

    x-y if x >  y
    +0    if x <= y
 */

int
mpfr_dim (mpfr_ptr z, mpfr_srcptr x ,mpfr_srcptr y , mp_rnd_t rnd_mode)
{
  if (MPFR_IS_NAN(x) || MPFR_IS_NAN(y))
    {
      MPFR_SET_NAN(z);
      MPFR_RET_NAN;
    }

  MPFR_CLEAR_NAN(z);

  if (mpfr_cmp(x,y) > 0)
    return mpfr_sub(z, x, y, rnd_mode);
  else
    {
      MPFR_SET_ZERO(z);
      MPFR_SET_POS(z);
      MPFR_RET(0);
    }
}