path: root/tests/tget_f.c

/* Test file for mpfr_get_f.

Copyright 2005-2016 Free Software Foundation, Inc.
Contributed by the AriC and Caramba 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 "mpfr-test.h"

#ifndef MPFR_USE_MINI_GMP

/* Test that there is no lost of accuracy when converting a mpfr_t number
   into a mpf_t number (test with various precisions and exponents). */
static void
prec_test (void)
{
  int px, py;

  for (py = 3; py <= 136; py++)
    {
      mpfr_t y1, y2, y3;

      mpfr_init2 (y1, py);
      mpfr_init2 (y2, py);
      mpfr_init2 (y3, py);

      for (px = 32; px <= 160; px += 32)
        {
          mpf_t x1, x2, x3;
          int e;

          mpf_init (x1);
          mpf_init (x2);
          mpf_init (x3);
          mpfr_set_ui_2exp (y1, 1, py - 1, MPFR_RNDN);
          mpfr_get_f (x1, y1, MPFR_RNDN);  /* exact (power of 2) */
          mpf_set (x2, x1);
          mpfr_set (y2, y1, MPFR_RNDN);

          for (e = py - 2; e >= 0; e--)
            {
              int inex;
              mpf_div_2exp (x2, x2, 1);
              mpf_add (x1, x1, x2);
              mpfr_div_2exp (y2, y2, 1, MPFR_RNDN);
              inex = mpfr_add (y1, y1, y2, MPFR_RNDN);
              MPFR_ASSERTN (inex == 0);
              mpfr_set_f (y3, x1, MPFR_RNDN);
              if (! mpfr_equal_p (y1, y3))
                break;
              inex = mpfr_get_f (x3, y3, MPFR_RNDN);
              if (mpf_cmp (x1, x3) != 0)
                {
                  printf ("Error in prec_test (px = %d, py = %d, e = %d)\n",
                          px, py, e);
                  printf ("x1 = ");
                  mpf_out_str (stdout, 16, 0, x1);
                  printf ("\nx2 = ");
                  mpf_out_str (stdout, 16, 0, x2);
                  printf ("\n");
                  exit (1);
                }
              if (inex != 0)
                {
                  printf ("Error in prec_test (px = %d, py = %d, e = %d)\n",
                          px, py, e);
                  printf ("wrong ternary value got: %+d, expected: 0\n",
                          inex);
                  exit (1);
                }
            }

          mpf_clear (x1);
          mpf_clear (x2);
          mpf_clear (x3);
        }

      mpfr_clear (y1);
      mpfr_clear (y2);
      mpfr_clear (y3);
    }
}

static void
special_test (void)
{
  int inex;
  mpf_t x;
  mpfr_t y;

  mpfr_init (y);
  mpf_init (x);

  mpfr_set_nan (y);
  mpfr_clear_flags ();
  mpfr_get_f (x, y, MPFR_RNDN);
  if (! mpfr_erangeflag_p ())
    {
      printf ("Error: mpfr_get_f(NaN) should raise erange flag\n");
      exit (1);
    }

  mpfr_set_inf (y, +1);
  mpfr_clear_flags ();
  inex = mpfr_get_f (x, y, MPFR_RNDN);
  if (inex >= 0)
    {
      printf ("Error: mpfr_get_f(+Inf) should return a negative ternary"
              "value\n");
      exit (1);
    }
  if (! mpfr_erangeflag_p ())
    {
      printf ("Error: mpfr_get_f(+Inf) should raise erange flag\n");
      exit (1);
    }

  mpfr_set_inf (y, -1);
  mpfr_clear_flags ();
  inex = mpfr_get_f (x, y, MPFR_RNDN);
  if (inex <= 0)
    {
      printf ("Error: mpfr_get_f(-Inf) should return a positive ternary"
              "value\n");
      exit (1);
    }
  if (! mpfr_erangeflag_p ())
    {
      printf ("Error: mpfr_get_f(-Inf) should raise erange flag\n");
      exit (1);
    }

  mpfr_set_ui (y, 0, MPFR_RNDN);
  if (mpfr_get_f (x, y, MPFR_RNDN) != 0 || mpf_cmp_ui (x, 0))
    {
      printf ("Error: mpfr_get_f(+0) fails\n");
      exit (1);
    }

  mpfr_set_ui (y, 0, MPFR_RNDN);
  mpfr_neg (y, y, MPFR_RNDN);
  if (mpfr_get_f (x, y, MPFR_RNDN) != 0 || mpf_cmp_ui (x, 0))
    {
      printf ("Error: mpfr_get_f(-0) fails\n");
      exit (1);
    }

  mpfr_clear (y);
  mpf_clear (x);
}

static void
ternary_test (void)
{
  int prec;
  int rnd;
  int inex, expected_inex;
  mpf_t x;
  mpfr_t y;

  mpf_init2 (x, 256);
  mpfr_init2 (y, 256);

  for (prec = 2; prec <= 256; prec++)
    {

      mpf_set_prec (x, prec);
      mpfr_set_prec (y, PREC (x) * GMP_NUMB_BITS + 1);

      /* y == 1 */
      mpfr_set_ui_2exp (y, 1, prec, MPFR_RNDN);

      RND_LOOP (rnd)
      {
        inex = mpfr_get_f (x, y, (mpfr_rnd_t) rnd);

        if (inex != 0 || mpfr_cmp_f (y, x) !=0)
          {
            printf ("Error in mpfr_get_f (x, y, %s)\nx = ",
                    mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
            mpf_out_str (stdout, 2, 0, x);
            printf ("\ny = ");
            mpfr_dump (y);
            if (inex != 0)
              printf ("got ternary value = %+d, expected: 0\n", inex);

            exit (1);
          }
      }

      /* y == 1 + epsilon */
      mpfr_nextbelow (y);

      RND_LOOP (rnd)
      {
        switch (rnd)
          {
          case MPFR_RNDU: case MPFR_RNDA:
          case MPFR_RNDN:
            expected_inex = +1;
            break;
          default :
            expected_inex = -1;
          }

        inex = mpfr_get_f (x, y, (mpfr_rnd_t) rnd);

        if (! SAME_SIGN (expected_inex, inex)
            || SAME_SIGN (expected_inex, mpfr_cmp_f (y, x)))
          {
            printf ("Error in mpfr_get_f (x, y, %s)\nx = ",
                    mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
            mpf_out_str (stdout, 2, 0, x);
            printf ("\ny = ");
            mpfr_dump (y);
            if (! SAME_SIGN (expected_inex, inex))
              printf ("got ternary value = %+d, expected: %+d\n",
                      inex, expected_inex);

            exit (1);
          }
      }

      /* y == positive random float */
      mpfr_random2 (y, MPFR_LIMB_SIZE (y), 1024, RANDS);

      RND_LOOP (rnd)
      {
        inex = mpfr_get_f (x, y, (mpfr_rnd_t) rnd);

        if (! SAME_SIGN (inex, -mpfr_cmp_f (y, x)))
          {
            printf ("Error in mpfr_get_f (x, y, %s)\nx = ",
                    mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
            mpf_out_str (stdout, 2, 0, x);
            printf ("\ny = ");
            mpfr_dump (y);
            printf ("got ternary value = %+d, expected: %+d\n",
                    inex, -mpfr_cmp_f (y, x));

            exit (1);
          }
      }
    }

  mpf_clear (x);
  mpfr_clear (y);
}

int
main (void)
{
  mpf_t x;
  mpfr_t y, z;
  unsigned long i;
  mpfr_exp_t e;
  int inex;

  tests_start_mpfr ();

  mpfr_init (y);
  mpfr_init (z);
  mpf_init (x);

  i = 1;
  while (i)
    {
      mpfr_set_ui (y, i, MPFR_RNDN);
      if (mpfr_get_f (x, y, MPFR_RNDN) != 0 || mpf_cmp_ui (x, i))
        {
          printf ("Error: mpfr_get_f(%lu) fails\n", i);
          exit (1);
        }
      if (i <= - (unsigned long) LONG_MIN)
        {
          long j = i < - (unsigned long) LONG_MIN ? - (long) i : LONG_MIN;
          mpfr_set_si (y, j, MPFR_RNDN);
          if (mpfr_get_f (x, y, MPFR_RNDN) != 0 || mpf_cmp_si (x, j))
            {
              printf ("Error: mpfr_get_f(-%lu) fails\n", i);
              exit (1);
            }
        }
      i *= 2;
    }

  /* same tests, but with a larger precision for y, which requires to
     round it */
  mpfr_set_prec (y, 100);
  i = 1;
  while (i)
    {
      mpfr_set_ui (y, i, MPFR_RNDN);
      inex = mpfr_get_f (x, y, MPFR_RNDN);
      if (! SAME_SIGN (inex, - mpfr_cmp_f (y, x)) || mpf_cmp_ui (x, i))
        {
          printf ("Error: mpfr_get_f(%lu) fails\n", i);
          exit (1);
        }
      mpfr_set_si (y, (signed long) -i, MPFR_RNDN);
      inex = mpfr_get_f (x, y, MPFR_RNDN);
      if (! SAME_SIGN (inex, - mpfr_cmp_f (y, x))
          || mpf_cmp_si (x, (signed long) -i))
        {
          printf ("Error: mpfr_get_f(-%lu) fails\n", i);
          exit (1);
        }
      i *= 2;
    }

  /* bug reported by Jim White */
  for (e = 0; e <= 2 * GMP_NUMB_BITS; e++)
    {
      /* test with 2^(-e) */
      mpfr_set_ui (y, 1, MPFR_RNDN);
      mpfr_div_2exp (y, y, e, MPFR_RNDN);
      inex = mpfr_get_f (x, y, MPFR_RNDN);
      mpf_mul_2exp (x, x, e);
      if (inex != 0 || mpf_cmp_ui (x, 1) != 0)
        {
          printf ("Error: mpfr_get_f(x,y,MPFR_RNDN) fails\n");
          printf ("y=");
          mpfr_dump (y);
          printf ("x=");
          mpf_div_2exp (x, x, e);
          mpf_out_str (stdout, 2, 0, x);
          exit (1);
        }

      /* test with 2^(e) */
      mpfr_set_ui (y, 1, MPFR_RNDN);
      mpfr_mul_2exp (y, y, e, MPFR_RNDN);
      inex = mpfr_get_f (x, y, MPFR_RNDN);
      mpf_div_2exp (x, x, e);
      if (inex != 0 || mpf_cmp_ui (x, 1) != 0)
        {
          printf ("Error: mpfr_get_f(x,y,MPFR_RNDN) fails\n");
          printf ("y=");
          mpfr_dump (y);
          printf ("x=");
          mpf_mul_2exp (x, x, e);
          mpf_out_str (stdout, 2, 0, x);
          exit (1);
        }
    }

  /* Bug reported by Yury Lukach on 2006-04-05 */
  mpfr_set_prec (y, 32);
  mpfr_set_prec (z, 32);
  mpf_set_prec (x, 32);
  mpfr_set_ui_2exp (y, 0xc1234567, -30, MPFR_RNDN);
  mpfr_get_f (x, y, MPFR_RNDN);
  inex = mpfr_set_f (z, x, MPFR_RNDN);
  if (inex != 0 || ! mpfr_equal_p (y, z))
    {
      printf ("Error in mpfr_get_f:\n  inex = %d, y = ", inex);
      mpfr_dump (z);
      printf ("Expected:\n  inex = 0, y = ");
      mpfr_dump (y);
      exit (1);
    }

  mpfr_clear (y);
  mpfr_clear (z);
  mpf_clear (x);

  special_test ();
  prec_test ();
  ternary_test ();

  tests_end_mpfr ();
  return 0;
}

#else

int
main (void)
{
  return 77;
}

#endif