/*

Copyright 2012, 2013 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 <limits.h>

#include <stdlib.h>

#include <stdio.h>

#include "testutils.h"

#define MAXBITS 400

#define COUNT 10000

/* Called when s is supposed to be floor(root(u,z)), and r = u - s^z */

static int

rootrem_valid_p (const mpz_t u, const mpz_t s, const mpz_t r, unsigned long z)

{

  mpz_t t;

  mpz_init (t);

  if (mpz_fits_ulong_p (s))

    mpz_ui_pow_ui (t, mpz_get_ui (s), z);

  else

    mpz_pow_ui (t, s, z);

  mpz_sub (t, u, t);

  if ((mpz_sgn (t) != mpz_sgn(u) && mpz_sgn (t) != 0) || mpz_cmp (t, r) != 0)

    {

      mpz_clear (t);

      return 0;

    }

  if (mpz_sgn (s) > 0)

    mpz_add_ui (t, s, 1);

  else

    mpz_sub_ui (t, s, 1);

  mpz_pow_ui (t, t, z);

  if (mpz_cmpabs (t, u) <= 0)

    {

      mpz_clear (t);

      return 0;

    }

  mpz_clear (t);

  return 1;

}

void

testmain (int argc, char **argv)

{

  unsigned i;

  unsigned long e;

  mpz_t u, s, r, bs;

  mpz_init (u);

  mpz_init (s);

  mpz_init (r);

  mpz_init (bs);

  for (i = 0; i < COUNT; i++)

    {

      mini_rrandomb (u, MAXBITS);

      mini_rrandomb (bs, 12);

      e = mpz_getlimbn (bs, 0) % mpz_sizeinbase (u, 2) + 1;

      if ((e & 1) && (mpz_getlimbn (bs, 0) & (1L<<10)))

	mpz_neg (u, u);

      mpz_rootrem (s, r, u, e);

      if (!rootrem_valid_p (u, s, r, e))

	{

	  fprintf (stderr, "mpz_rootrem(%lu-th) failed:\n", e);

	  dump ("u", u);

	  dump ("root", s);

	  dump ("rem", r);

	  abort ();

	}

    }

  mpz_clear (bs);

  mpz_clear (u);

  mpz_clear (s);

  mpz_clear (r);

}