xref: /src/external/lgpl3/mpfr/dist/tests/tget_z.c

/* Test file for mpz_set_fr / mpfr_get_z.

Copyright 2004, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.

This file is part of the GNU MPFR Library.

The GNU MPFR 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 MPFR 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 MPFR Library; see the file COPYING.LESSER.  If not, see
http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */

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

#include "mpfr-test.h"

static void
check_diff (void)
{
  int inex;
  mpfr_t x;
  mpz_t  z;
  mpfr_exp_t emin;

  mpz_init   (z);
  mpfr_init2 (x, 2);

  mpfr_set_ui (x, 2047, MPFR_RNDU);
  mpz_set_fr (z, x, MPFR_RNDN);
  if (mpz_cmp_ui (z, 2048) != 0)
    {
      printf ("get_z RU 2048 failed\n");
      exit (1);
    }

  mpfr_set_prec (x, 6);
  mpfr_set_str (x, "17.5", 10, MPFR_RNDN);
  inex = mpfr_get_z (z, x, MPFR_RNDN);
  if (inex <= 0 || mpz_cmp_ui (z, 18) != 0)
    {
      printf ("get_z RN 17.5 failed\n");
      exit (1);
    }

  /* save default emin */
  emin = mpfr_get_emin ();;

  mpfr_set_emin (17);
  mpfr_set_ui (x, 0, MPFR_RNDN);
  inex = mpfr_get_z (z, x, MPFR_RNDN);
  if (inex != 0 || mpz_cmp_ui (z, 0) != 0)
    {
      printf ("get_z 0 failed\n");
      exit (1);
    }

  /* restore default emin */
  mpfr_set_emin (emin);

  mpfr_clear (x);
  mpz_clear  (z);
}

static void
check_one (mpz_ptr z)
{
  int    inex;
  int    sh, neg;
  mpfr_t f;
  mpz_t  got;

  mpfr_init2 (f, MAX( mpz_sizeinbase (z, 2), MPFR_PREC_MIN) );
  mpz_init (got);

  for (sh = -2*GMP_NUMB_BITS ; sh < 2*GMP_NUMB_BITS ; sh++)
    {
      for (neg = 0; neg <= 1; neg++)
        {
          mpz_neg (z, z);
          mpfr_set_z (f, z, MPFR_RNDN);

          if (sh < 0)
            {
              mpz_tdiv_q_2exp (z, z, -sh);
              mpfr_div_2exp (f, f, -sh, MPFR_RNDN);
            }
          else
            {
              mpz_mul_2exp (z, z, sh);
              mpfr_mul_2exp (f, f, sh, MPFR_RNDN);
            }

          inex = mpfr_get_z (got, f, MPFR_RNDZ);

          if (mpz_cmp (got, z) != 0)
            {
              printf ("Wrong result for shift=%d\n", sh);
              printf ("     f "); mpfr_dump (f);
              printf ("   got "); mpz_dump (got);
              printf ("  want "); mpz_dump (z);
              exit (1);
            }
          if (! SAME_SIGN (inex, - mpfr_cmp_z (f, z)))
            {
              printf ("Wrong inexact value for shift=%d\n", sh);
              printf ("    f "); mpfr_dump (f);
              printf ("  got %+d\n", inex);
              printf (" want %+d\n", -mpfr_cmp_z (f, z));
              exit (1);
            }
        }
    }

  mpfr_clear (f);
  mpz_clear (got);
}

static void
check (void)
{
  mpz_t  z;

  mpz_init (z);

  mpz_set_ui (z, 0L);
  check_one (z);

  mpz_set_si (z, 123L);
  check_one (z);

  mpz_rrandomb (z, RANDS, 2*GMP_NUMB_BITS);
  check_one (z);

  mpz_rrandomb (z, RANDS, 5*GMP_NUMB_BITS);
  check_one (z);

  mpz_clear (z);
}

static void
special (void)
{
  int inex;
  mpfr_t x;
  mpz_t z;
  int i;
  mpfr_exp_t e;

  mpfr_init2 (x, 2);
  mpz_init (z);

  for (i = -1; i <= 1; i++)
    {
      if (i != 0)
        mpfr_set_nan (x);
      else
        mpfr_set_inf (x, i);
      mpfr_clear_flags ();
      inex = mpfr_get_z (z, x, MPFR_RNDN);
      if (!mpfr_erangeflag_p () || inex != 0 || mpz_cmp_ui (z, 0) != 0)
        {
          printf ("special() failed on mpfr_get_z for i = %d\n", i);
          exit (1);
        }
      mpfr_clear_flags ();
      e = mpfr_get_z_2exp (z, x);
      if (!mpfr_erangeflag_p () || e != __gmpfr_emin ||
          mpz_cmp_ui (z, 0) != 0)
        {
          printf ("special() failed on mpfr_get_z_2exp for i = %d\n", i);
          exit (1);
        }
    }

  mpfr_clear (x);
  mpz_clear (z);
}

int
main (void)
{
  tests_start_mpfr ();

  check ();
  check_diff ();
  special ();

  tests_end_mpfr ();
  return 0;
}