/* Test mpz_remove.

Copyright 1991, 1993, 1994, 1996, 1997, 2000, 2001, 2009 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 3 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.  If not, see http://www.gnu.org/licenses/.  */

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

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

void debug_mp __GMP_PROTO ((mpz_t));
unsigned long int mpz_refremove __GMP_PROTO ((mpz_t, const mpz_t, const mpz_t));

int
main (int argc, char **argv)
{
  unsigned long int exp;
  mpz_t t, dest, refdest, dividend, divisor;
  mp_size_t dividend_size, divisor_size;
  int i;
  int reps = 100;
  unsigned long int pwr, refpwr;
  gmp_randstate_ptr rands;
  mpz_t bs;
  unsigned long size_range;

  tests_start ();
  rands = RANDS;

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

  mpz_init (bs);
  mpz_init (t);
  mpz_init (dest);
  mpz_init (refdest);
  mpz_init (dividend);
  mpz_init (divisor);

  for (i = 0; i < reps; i++)
    {
      mpz_urandomb (bs, rands, 32);
      size_range = mpz_get_ui (bs) % 18 + 2; /* 0..524288 bit operands */

      do
	{
	  mpz_urandomb (bs, rands, size_range);
	  divisor_size = mpz_get_ui (bs);
	  mpz_rrandomb (divisor, rands, divisor_size);
	}
      while (mpz_cmp_ui (divisor, 1) <= 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, 32);
      exp = mpz_get_ui (bs) % (5 + 10000 / mpz_sizeinbase (divisor, 2));
      mpz_pow_ui (t, divisor, exp);
      mpz_mul (dividend, dividend, t);

      refpwr = mpz_refremove (refdest, dividend, divisor);
      pwr = mpz_remove (dest, dividend, divisor);

      if (refpwr != pwr || mpz_cmp (refdest, dest) != 0)
	{
	  fprintf (stderr, "ERROR after %d tests\n", i);
	  fprintf (stderr, "refpower = %lu\n", refpwr);
	  fprintf (stderr, "   power = %lu\n", pwr);
	  fprintf (stderr, "    op1 = "); debug_mp (dividend);
	  fprintf (stderr, "    op2 = "); debug_mp (divisor);
	  fprintf (stderr, "refdest = "); debug_mp (refdest);
	  fprintf (stderr, "   dest = "); debug_mp (dest);
	  abort ();
	}
    }

  tests_end ();
  exit (0);
}

unsigned long int
mpz_refremove (mpz_t dest, const mpz_t src, const mpz_t f)
{
  unsigned long int pwr;
  mpz_t rem, x;

  mpz_init (rem);
  mpz_init (x);

  mpz_set (dest, src);
  for (pwr = 0;; pwr++)
    {
      mpz_tdiv_qr (x, rem, dest, f);
      if (mpz_cmp_ui (rem, 0) != 0)
	break;
      mpz_set (dest, x);
    }

  mpz_clear (x);
  mpz_clear (rem);
  return pwr;
}

void
debug_mp (mpz_t x)
{
  size_t siz = mpz_sizeinbase (x, 16);

  if (siz > 65)
    {
      mpz_t q;
      mpz_init (q);
      mpz_tdiv_q_2exp (q, x, 4 * (mpz_sizeinbase (x, 16) - 25));
      gmp_fprintf (stderr, "%ZX...", q);
      mpz_tdiv_r_2exp (q, x, 4 * 25);
      gmp_fprintf (stderr, "%025ZX [%d]\n", q, (int) siz);
      mpz_clear (q);
    }
  else
    {
      gmp_fprintf (stderr, "%ZX\n", x);
    }
}