/* Test mpf_sub.

Copyright (C) 1996 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP 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 GNU MP 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 GNU MP Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */

#include <stdio.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "urandom.h"

#ifndef SIZE
#define SIZE 16
#endif

#if __STDC__
void ref_mpf_add (mpf_t, const mpf_t, const mpf_t);
void ref_mpf_sub (mpf_t, const mpf_t, const mpf_t);
#else
void ref_mpf_add ();
void ref_mpf_sub ();
#endif

main (argc, argv)
     int argc;
     char **argv;
{
  mp_size_t size;
  mp_exp_t exp;
  int reps = 500000;
  int i;
  mpf_t u, v, w, wref;
  mp_size_t bprec = 100;
  mpf_t rerr, max_rerr, limit_rerr;

  if (argc > 1)
    {
      reps = strtol (argv[1], 0, 0);
      if (argc > 2)
	bprec = strtol (argv[2], 0, 0);
    }

  mpf_set_default_prec (bprec);

  mpf_init_set_ui (limit_rerr, 1);
  mpf_div_2exp (limit_rerr, limit_rerr, bprec);
#if VERBOSE
  mpf_dump (limit_rerr);
#endif
  mpf_init (rerr);
  mpf_init_set_ui (max_rerr, 0);

  mpf_init (u);
  mpf_init (v);
  mpf_init (w);
  mpf_init (wref);
  for (i = 0; i < reps; i++)
    {
      size = urandom () % (2 * SIZE) - SIZE;
      exp = urandom () % SIZE;
      mpf_random2 (u, size, exp);

      size = urandom () % (2 * SIZE) - SIZE;
      exp = urandom () % SIZE;
      mpf_random2 (v, size, exp);

      if ((urandom () & 1) != 0)
	mpf_add_ui (u, v, 1);
      else if ((urandom () & 1) != 0)
	mpf_sub_ui (u, v, 1);

      mpf_sub (w, u, v);
      ref_mpf_sub (wref, u, v);

      mpf_reldiff (rerr, w, wref);
      if (mpf_cmp (rerr, max_rerr) > 0)
	{
	  mpf_set (max_rerr, rerr);
#if VERBOSE
	  mpf_dump (max_rerr);
#endif
	  if (mpf_cmp (rerr, limit_rerr) > 0)
	    {
	      printf ("ERROR after %d tests\n", i);
	      printf ("   u = "); mpf_dump (u);
	      printf ("   v = "); mpf_dump (v);
	      printf ("wref = "); mpf_dump (wref);
	      printf ("   w = "); mpf_dump (w);
	      abort ();
	    }
	}
    }

  exit (0);
}

oo (x)
     mpf_t x;
{
  mp_size_t i;
  printf (" exp = %ld\n", x->_mp_exp);
  printf ("size = %d\n", x->_mp_size);
  for (i = ABS (x->_mp_size) - 1; i >= 0; i--)
    printf ("%08lX ", x->_mp_d[i]);
  printf ("\n");
  mpf_dump (x);
}