third_party/gmp/tests/mpf/t-dm2exp.c

/* Test mpf_div, mpf_div_2exp, mpf_mul_2exp.

Copyright 1996, 2000, 2001 Free Software Foundation, Inc.

This file is part of the GNU MP Library test suite.

The GNU MP Library test suite is free software; you can redistribute it
and/or modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 3 of the License,
or (at your option) any later version.

The GNU MP Library test suite 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 General
Public License for more details.

You should have received a copy of the GNU General Public License along with
the GNU MP Library test suite.  If not, see https://www.gnu.org/licenses/.  */

#include <stdio.h>
#include <stdlib.h>

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

#ifndef SIZE
#define SIZE 16
#endif

int
main (int argc, char **argv)
{
  int reps = 100000;
  int i;
  mpf_t u, v, w1, w2, w3;
  mp_size_t bprec = 100;
  mpf_t rerr, limit_rerr;
  mp_size_t un;
  mp_exp_t ue;

  tests_start ();

  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 (rerr);
  mpf_init (limit_rerr);

  mpf_init (u);
  mpf_init (v);
  mpf_init (w1);
  mpf_init (w2);
  mpf_init (w3);

  for (i = 0; i < reps; i++)
    {
      unsigned long int res_prec;
      unsigned long int pow2;

      res_prec = urandom () % (bprec + 100);
      mpf_set_prec (w1, res_prec);
      mpf_set_prec (w2, res_prec);
      mpf_set_prec (w3, res_prec);

      mpf_set_ui (limit_rerr, 1);
      mpf_div_2exp (limit_rerr, limit_rerr, res_prec);

      pow2 = urandom () % 0x10000;
      mpf_set_ui (v, 1);
      mpf_mul_2exp (v, v, pow2);

      un = urandom () % (2 * SIZE) - SIZE;
      ue = urandom () % SIZE;
      mpf_random2 (u, un, ue);

      mpf_div_2exp (w1, u, pow2);
      mpf_div (w2, u, v);
      mpf_reldiff (rerr, w1, w2);
      if (mpf_cmp (rerr, limit_rerr) > 0)
	{
	  printf ("ERROR in mpf_div or mpf_div_2exp after %d tests\n", i);
	  printf ("   u = "); mpf_dump (u);
	  printf ("   v = "); mpf_dump (v);
	  printf ("  w1 = "); mpf_dump (w1);
	  printf ("  w2 = "); mpf_dump (w2);
	  abort ();
	}
      mpf_mul_2exp (w3, w1, pow2);
      mpf_reldiff (rerr, u, w3);
      if (mpf_cmp (rerr, limit_rerr) > 0)
	{
	  printf ("ERROR in mpf_mul_2exp after %d tests\n", i);
	  printf ("   u = "); mpf_dump (u);
	  printf ("   v = "); mpf_dump (v);
	  printf ("  w1 = "); mpf_dump (w1);
	  printf ("  w3 = "); mpf_dump (w3);
	  abort ();
	}
    }

  mpf_clear (rerr);
  mpf_clear (limit_rerr);

  mpf_clear (u);
  mpf_clear (v);
  mpf_clear (w1);
  mpf_clear (w2);
  mpf_clear (w3);

  tests_end ();
  exit (0);
}