tests/tmodf.c

/* Test file for mpfr_modf.

Copyright 2007, 2008, 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
Contributed by the AriC and Caramel 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"

#if MPFR_VERSION >= MPFR_VERSION_NUM(2,4,0)

static void
check (const char *xis, const char *xfs, const char *xs,
       mpfr_prec_t xip, mpfr_prec_t xfp, mpfr_prec_t xp,
       int expected_return, mpfr_rnd_t rnd_mode)
{
  int inexact;
  mpfr_t xi, xf, x;

  mpfr_init2 (xi, xip);
  mpfr_init2 (xf, xfp);
  mpfr_init2 (x, xp);
  mpfr_set_str1 (x, xs);
  inexact = mpfr_modf (xi, xf, x, rnd_mode);
  if (mpfr_cmp_str1 (xi, xis))
    {
      printf ("mpfr_modf failed for x=%s, rnd=%s\n",
              xs, mpfr_print_rnd_mode(rnd_mode));
      printf ("got integer value: ");
      mpfr_out_str (stdout, 10, 0, xi, MPFR_RNDN);
      printf ("\nexpected %s\n", xis);
      exit (1);
    }
  if (mpfr_cmp_str1 (xf, xfs))
    {
      printf ("mpfr_modf failed for x=%s, rnd=%s\n",
              xs, mpfr_print_rnd_mode(rnd_mode));
      printf ("got fractional value: ");
      mpfr_out_str (stdout, 10, 0, xf, MPFR_RNDN);
      printf ("\nexpected %s\n", xfs);
      exit (1);
    }
  if (inexact != expected_return)
    {
      printf ("mpfr_modf failed for x=%s, rnd=%s\n",
              xs, mpfr_print_rnd_mode(rnd_mode));
      printf ("got return value: %d, expected %d\n", inexact, expected_return);
      exit (1);
    }
  mpfr_clears (xi, xf, x, (mpfr_ptr) 0);
}

static void
check_nans (void)
{
  mpfr_t  x, xi, xf;

  mpfr_init2 (x, 123);
  mpfr_init2 (xi, 123);
  mpfr_init2 (xf, 123);

  /* nan */
  mpfr_set_nan (x);
  mpfr_modf (xi, xf, x, MPFR_RNDN);
  MPFR_ASSERTN (mpfr_nan_p (xi));
  MPFR_ASSERTN (mpfr_nan_p (xf));

  /* +inf */
  mpfr_set_inf (x, 1);
  mpfr_modf (xi, xf, x, MPFR_RNDN);
  MPFR_ASSERTN (mpfr_inf_p (xi));
  MPFR_ASSERTN (mpfr_sgn (xi) > 0);
  MPFR_ASSERTN (mpfr_zero_p (xf));

  /* -inf */
  mpfr_set_inf (x, -1);
  mpfr_modf (xi ,xf, x, MPFR_RNDN);
  MPFR_ASSERTN (mpfr_inf_p (xi));
  MPFR_ASSERTN (mpfr_sgn (xi) < 0);
  MPFR_ASSERTN (mpfr_zero_p (xf));

  mpfr_clear (x);
  mpfr_clear (xi);
  mpfr_clear (xf);
}

static void
check_special_exprange (void)
{
  int inexact, ov;
  unsigned int eflags, gflags;
  mpfr_t xi, xf, x;
  mpfr_exp_t emax;

  emax = mpfr_get_emax ();
  mpfr_init2 (xi, 7);
  mpfr_init2 (xf, 7);
  mpfr_init2 (x, 8);

  mpfr_set_str (x, "0.11111111", 2, MPFR_RNDN);
  for (ov = 0; ov <= 1; ov++)
    {
      const char *s = ov ? "@Inf@" : "1";

      if (ov)
        set_emax (0);
      mpfr_clear_flags ();
      inexact = mpfr_modf (xi, xf, x, MPFR_RNDN);
      gflags = __gmpfr_flags;
      set_emax (emax);
      if (MPFR_NOTZERO (xi) || MPFR_IS_NEG (xi) ||
          mpfr_cmp_str1 (xf, s) != 0)
        {
          printf ("Error in check_special_exprange (ov = %d):"
                  " expected 0 and %s, got\n", ov, s);
          mpfr_out_str (stdout, 2, 0, xi, MPFR_RNDN);
          printf (" and ");
          mpfr_out_str (stdout, 2, 0, xf, MPFR_RNDN);
          printf ("\n");
          exit (1);
        }
      if (inexact != 4)
        {
          printf ("Bad inexact value in check_special_exprange (ov = %d):"
                  " expected 4, got %d\n", ov, inexact);
          exit (1);
        }
      eflags = MPFR_FLAGS_INEXACT | (ov ? MPFR_FLAGS_OVERFLOW : 0);
      if (gflags != eflags)
        {
          printf ("Bad flags in check_special_exprange (ov = %d):"
                  " expected %u, got %u\n", ov, eflags, gflags);
          exit (1);
        }
    }

  /* Test if an overflow occurs in mpfr_set for ope >= opq. */
  mpfr_set_emax (MPFR_EMAX_MAX);
  mpfr_set_inf (x, 1);
  mpfr_nextbelow (x);
  mpfr_clear_flags ();
  inexact = mpfr_modf (xi, xf, x, MPFR_RNDN);
  gflags = __gmpfr_flags;
  if (mpfr_cmp_str1 (xi, "@Inf@") != 0 ||
      MPFR_NOTZERO (xf) || MPFR_IS_NEG (xf))
    {
      printf ("Error in check_special_exprange:"
              " expected 0 and @Inf@, got\n");
      mpfr_out_str (stdout, 2, 0, xi, MPFR_RNDN);
      printf (" and ");
      mpfr_out_str (stdout, 2, 0, xf, MPFR_RNDN);
      printf ("\n");
      exit (1);
    }
  if (inexact != 1)
    {
      printf ("Bad inexact value in check_special_exprange:"
              " expected 1, got %d\n", inexact);
      exit (1);
    }
  eflags = MPFR_FLAGS_INEXACT | MPFR_FLAGS_OVERFLOW;
  if (gflags != eflags)
    {
      printf ("Bad flags in check_special_exprange:"
              " expected %u, got %u\n", eflags, gflags);
      exit (1);
    }
  set_emax (emax);

  /* Test if an underflow occurs in the general case. TODO */

  mpfr_clears (xi, xf, x, (mpfr_ptr) 0);
}

int
main (int argc, char *argv[])
{
  tests_start_mpfr ();

  check_nans ();

  /* integer part is exact, frac. part is exact: return value should be 0 */
  check ("61680","3.52935791015625e-1", "61680.352935791015625",
         53, 53, 53, 0, MPFR_RNDZ);
  /* integer part is rounded up, fractional part is rounded up: return value
     should be 1+4*1=5 */
  check ("-53968","-3.529052734375e-1", "-53970.352935791015625",
         13, 13, 53, 5, MPFR_RNDZ);
  /* integer part is rounded down, fractional part is rounded down:
     return value should be 2+4*2=10 */
  check ("61632","3.525390625e-1",      "61648.352935791015625",
         10, 10, 53, 10, MPFR_RNDZ);
  check ("61680", "0", "61680",  53, 53, 53, 0, MPFR_RNDZ);
  /* integer part is rounded up, fractional part is exact: 1 */
  check ("-53968","0", "-53970", 13, 13, 53, 1, MPFR_RNDZ);
  /* integer part is rounded up, fractional part is exact: 1 */
  check ("-43392","0", "-43399", 13, 13, 53, 1, MPFR_RNDU);
  /* integer part is rounded down, fractional part is exact: 2 */
  check ("-52720","0", "-52719", 13, 13, 53, 2, MPFR_RNDD);
  /* integer part is rounded down, fractional part is exact: 2 */
  check ("61632", "0", "61648",  10, 10, 53, 2, MPFR_RNDZ);

  check_special_exprange ();

  tests_end_mpfr ();
  return 0;
}

#else

int
main (void)
{
  printf ("Warning! Test disabled for this MPFR version.\n");
  return 0;
}

#endif