/* Test file for mpfr_get_f.

Copyright 2005, 2006, 2007 Free Software Foundation, Inc.
Contributed by the Arenaire and Cacao projects, INRIA.

This file is part of the MPFR Library.

The 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 2.1 of the License, or (at your
option) any later version.

The 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 MPFR Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
MA 02110-1301, USA. */

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

#include "mpfr-test.h"

/* 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, GMP_RNDN);
          mpfr_get_f (x1, y1, GMP_RNDN);  /* exact (power of 2) */
          mpf_set (x2, x1);
          mpfr_set (y2, y1, GMP_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, GMP_RNDN);
              inex = mpfr_add (y1, y1, y2, GMP_RNDN);
              MPFR_ASSERTN (inex == 0);
              mpfr_set_f (y3, x1, GMP_RNDN);
              if (! mpfr_equal_p (y1, y3))
                break;
              mpfr_get_f (x3, y3, GMP_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, x1);
                  printf ("\n");
                  exit (1);
                }
            }

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

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

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

  MPFR_TEST_USE_RANDS ();
  tests_start_mpfr ();

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

  mpfr_set_nan (y);
  if (mpfr_get_f (x, y, GMP_RNDN) == 0)
    {
      printf ("Error: mpfr_get_f(NaN) should fail\n");
      exit (1);
    }

  mpfr_set_inf (y, 1);
  if (mpfr_get_f (x, y, GMP_RNDN) == 0)
    {
      printf ("Error: mpfr_get_f(+Inf) should fail\n");
      exit (1);
    }

  mpfr_set_inf (y, -1);
  if (mpfr_get_f (x, y, GMP_RNDN) == 0)
    {
      printf ("Error: mpfr_get_f(-Inf) should fail\n");
      exit (1);
    }

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

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

  i = 1;
  while (i)
    {
      mpfr_set_ui (y, i, GMP_RNDN);
      if (mpfr_get_f (x, y, GMP_RNDN) || 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, GMP_RNDN);
          if (mpfr_get_f (x, y, GMP_RNDN) || 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, GMP_RNDN);
      if (mpfr_get_f (x, y, GMP_RNDN) || mpf_cmp_ui (x, i))
        {
          printf ("Error: mpfr_get_f(%lu) fails\n", i);
          exit (1);
        }
      mpfr_set_si (y, (signed long) -i, GMP_RNDN);
      if (mpfr_get_f (x, y, GMP_RNDN) || 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 * BITS_PER_MP_LIMB; e++)
    {
      /* test with 2^(-e) */
      mpfr_set_ui (y, 1, GMP_RNDN);
      mpfr_div_2exp (y, y, e, GMP_RNDN);
      mpfr_get_f (x, y, GMP_RNDN);
      mpf_mul_2exp (x, x, e);
      if (mpf_cmp_ui (x, 1) != 0)
        {
          printf ("Error: mpfr_get_f(x,y,GMP_RNDN) fails\n");
          printf ("y=");
          mpfr_dump (y);
          printf ("x=");
          mpf_div_2exp (x, x, e);
          mpf_dump (x);
          exit (1);
        }

      /* test with 2^(e) */
      mpfr_set_ui (y, 1, GMP_RNDN);
      mpfr_mul_2exp (y, y, e, GMP_RNDN);
      mpfr_get_f (x, y, GMP_RNDN);
      mpf_div_2exp (x, x, e);
      if (mpf_cmp_ui (x, 1) != 0)
        {
          printf ("Error: mpfr_get_f(x,y,GMP_RNDN) fails\n");
          printf ("y=");
          mpfr_dump (y);
          printf ("x=");
          mpf_mul_2exp (x, x, e);
          mpf_dump (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, GMP_RNDN);
  mpfr_get_f (x, y, GMP_RNDN);
  inex = mpfr_set_f (z, x, GMP_RNDN);
  if (inex || ! 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);

  prec_test ();

  tests_end_mpfr ();
  return 0;
}