/* Test mpz_set_d and mpz_init_set_d.

Copyright 2000-2003, 2006 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.h"

#include "gmp-impl.h"

#include "tests.h"

void

check_data (void)

{

  static const struct {

    double     d;

    mp_size_t  want_size;

    mp_limb_t  want_data[2];

  } data[] = {

    {  0.0,  0 },

    {  1.0,  1, { 1 } },

    { -1.0, -1, { 1 } },

    {  123.0,  1, { 123 } },

    { -123.0, -1, { 123 } },

    { 1e-1, 0, { 0 } },

    { -1e-1, 0, { 0 } },

    { 2.328306436538696e-10, 0, { 0 } },

    { -2.328306436538696e-10, 0, { 0 } },

    { 5.421010862427522e-20, 0, { 0 } },

    { -5.421010862427522e-20, 0, { 0 } },

    { 2.938735877055719e-39, 0, { 0 } },

    { -2.938735877055719e-39, 0, { 0 } },

  };

  mpz_t  z;

  int    i;

  for (i = 0; i < numberof (data); i++)

    {

      mpz_init (z);

      mpz_set_d (z, data[i].d);

      MPZ_CHECK_FORMAT (z);

      if (z->_mp_size != data[i].want_size

          || refmpn_cmp_allowzero (z->_mp_d, data[i].want_data,

                                   ABS (data[i].want_size)) != 0)

        {

          printf ("mpz_set_d wrong on data[%d]\n", i);

        bad:

          d_trace   ("  d  ", data[i].d);

          printf    ("  got  size %ld\n", (long) z->_mp_size);

          printf    ("  want size %ld\n", (long) data[i].want_size);

          mpn_trace ("  got  z", z->_mp_d, z->_mp_size);

          mpn_trace ("  want z", data[i].want_data, data[i].want_size);

          abort();

        }

      mpz_clear (z);

      mpz_init_set_d (z, data[i].d);

      MPZ_CHECK_FORMAT (z);

      if (z->_mp_size != data[i].want_size

          || refmpn_cmp_allowzero (z->_mp_d, data[i].want_data,

                                   ABS (data[i].want_size)) != 0)

        {

          printf ("mpz_init_set_d wrong on data[%d]\n", i);

          goto bad;

        }

      mpz_clear (z);

    }

}

/* Try mpz_set_d on values 2^i+1, while such a value fits a double. */

void

check_2n_plus_1 (void)

{

  volatile double  p, d, diff;

  mpz_t  want, got;

  int    i;

  mpz_init (want);

  mpz_init (got);

  p = 1.0;

  mpz_set_ui (want, 2L);  /* gives 3 on first step */

  for (i = 1; i < 500; i++)

    {

      mpz_mul_2exp (want, want, 1L);

      mpz_sub_ui (want, want, 1L);   /* want = 2^i+1 */

      p *= 2.0;  /* p = 2^i */

      d = p + 1.0;

      diff = d - p;

      if (diff != 1.0)

        break;   /* rounding occurred, stop now */

      mpz_set_d (got, d);

      MPZ_CHECK_FORMAT (got);

      if (mpz_cmp (got, want) != 0)

        {

          printf ("mpz_set_d wrong on 2^%d+1\n", i);

          d_trace   ("  d ", d);

          mpz_trace ("  got  ", got);

          mpz_trace ("  want ", want);

          abort ();

        }

    }

  mpz_clear (want);

  mpz_clear (got);

}

int

main (void)

{

  tests_start ();

  check_data ();

  check_2n_plus_1 ();

  tests_end ();

  exit (0);

}