mpir/tests/mpz/t-fdiv.c

/* Test mpz_abs, mpz_add, mpz_cmp, mpz_cmp_ui, mpz_fdiv_qr, mpz_fdiv_q,
   mpz_fdiv_r, mpz_mul.

Copyright 1993, 1994, 1996, 2000, 2001 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., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA. */

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

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

void dump_abort _PROTO ((mpz_t, mpz_t));
void debug_mp _PROTO ((mpz_t, int));

int
main (int argc, char **argv)
{
  mpz_t dividend, divisor;
  mpz_t quotient, remainder;
  mpz_t quotient2, remainder2;
  mpz_t temp;
  mp_size_t dividend_size, divisor_size;
  int i;
  int reps = 200;
  gmp_randstate_ptr rands;
  mpz_t bs;
  unsigned long bsi, size_range;

  tests_start ();
  rands = RANDS;

  mpz_init (bs);

  if (argc == 2)
     reps = atoi (argv[1]);

  mpz_init (dividend);
  mpz_init (divisor);
  mpz_init (quotient);
  mpz_init (remainder);
  mpz_init (quotient2);
  mpz_init (remainder2);
  mpz_init (temp);

  for (i = 0; i < reps; i++)
    {
      mpz_urandomb (bs, rands, 32);
      size_range = mpz_get_ui (bs) % 16 + 2; /* 0..131071 bit operands */

      do
	{
	  mpz_urandomb (bs, rands, size_range);
	  divisor_size = mpz_get_ui (bs);
	  mpz_rrandomb (divisor, rands, divisor_size);
	}
      while (mpz_sgn (divisor) == 0);

      mpz_urandomb (bs, rands, size_range);
      dividend_size = mpz_get_ui (bs) + divisor_size;
      mpz_rrandomb (dividend, rands, dividend_size);

      mpz_urandomb (bs, rands, 2);
      bsi = mpz_get_ui (bs);
      if ((bsi & 1) != 0)
	mpz_neg (dividend, dividend);
      if ((bsi & 2) != 0)
	mpz_neg (divisor, divisor);

      /* printf ("%ld %ld\n", SIZ (dividend), SIZ (divisor)); */

      mpz_fdiv_qr (quotient, remainder, dividend, divisor);
      mpz_fdiv_q (quotient2, dividend, divisor);
      mpz_fdiv_r (remainder2, dividend, divisor);

      /* First determine that the quotients and remainders computed
	 with different functions are equal.  */
      if (mpz_cmp (quotient, quotient2) != 0)
	dump_abort (dividend, divisor);
      if (mpz_cmp (remainder, remainder2) != 0)
	dump_abort (dividend, divisor);

      /* Check if the sign of the quotient is correct.  */
      if (mpz_cmp_ui (quotient, 0) != 0)
	if ((mpz_cmp_ui (quotient, 0) < 0)
	    != ((mpz_cmp_ui (dividend, 0) ^ mpz_cmp_ui (divisor, 0)) < 0))
	dump_abort (dividend, divisor);

      /* Check if the remainder has the same sign as the divisor
	 (quotient rounded towards minus infinity).  */
      if (mpz_cmp_ui (remainder, 0) != 0)
	if ((mpz_cmp_ui (remainder, 0) < 0) != (mpz_cmp_ui (divisor, 0) < 0))
	  dump_abort (dividend, divisor);

      mpz_mul (temp, quotient, divisor);
      mpz_add (temp, temp, remainder);
      if (mpz_cmp (temp, dividend) != 0)
	dump_abort (dividend, divisor);

      mpz_abs (temp, divisor);
      mpz_abs (remainder, remainder);
      if (mpz_cmp (remainder, temp) >= 0)
	dump_abort (dividend, divisor);
    }

  mpz_clear (bs);
  mpz_clear (dividend);
  mpz_clear (divisor);
  mpz_clear (quotient);
  mpz_clear (remainder);
  mpz_clear (quotient2);
  mpz_clear (remainder2);
  mpz_clear (temp);

  tests_end ();
  exit (0);
}

void
dump_abort (mpz_t dividend, mpz_t divisor)
{
  fprintf (stderr, "ERROR\n");
  fprintf (stderr, "dividend = "); debug_mp (dividend, -16);
  fprintf (stderr, "divisor  = "); debug_mp (divisor, -16);
  abort();
}

void
debug_mp (mpz_t x, int base)
{
  mpz_out_str (stderr, base, x); fputc ('\n', stderr);
}