/* Test file for mpfr_can_round.

Copyright 1999, 2001-2015 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"

#define MAX_LIMB_SIZE 100

static void
check_round_p (void)
{
  mp_limb_t buf[MAX_LIMB_SIZE];
  mp_size_t n, i;
  mpfr_prec_t p;
  mpfr_exp_t err;
  int r1, r2;

  for (n = 2 ; n <= MAX_LIMB_SIZE ; n++)
    {
      /* avoid mpn_random which leaks memory */
      for (i = 0; i < n; i++)
        buf[i] = randlimb ();
      p = randlimb() % ((n-1) * GMP_NUMB_BITS) + MPFR_PREC_MIN;
      err = p + randlimb () % GMP_NUMB_BITS;
      r1 = mpfr_round_p (buf, n, err, p);
      r2 = mpfr_can_round_raw (buf, n, MPFR_SIGN_POS, err,
                               MPFR_RNDN, MPFR_RNDZ, p);
      if (r1 != r2)
        {
          printf ("mpfr_round_p(%d) != mpfr_can_round(%d)!\n"
                  "bn = %ld, err0 = %ld, prec = %lu\nbp = ",
                  r1, r2, n, (long) err, (unsigned long) p);
          gmp_printf ("%NX\n", buf, n);
          exit (1);
        }
    }
}

int
main (void)
{
  mpfr_t x;
  mpfr_prec_t i, j;

  tests_start_mpfr ();

  /* checks that rounds to nearest sets the last
     bit to zero in case of equal distance */
  mpfr_init2 (x, 59);
  mpfr_set_str_binary (x, "-0.10010001010111000011110010111010111110000000111101100111111E663");
  if (mpfr_can_round (x, 54, MPFR_RNDZ, MPFR_RNDZ, 53) != 0)
    {
      printf ("Error (1) in mpfr_can_round\n");
      exit (1);
    }

  mpfr_set_str_binary (x, "-Inf");
  if (mpfr_can_round (x, 2000, MPFR_RNDZ, MPFR_RNDZ, 2000) != 0)
    {
      printf ("Error (2) in mpfr_can_round\n");
      exit (1);
    }

  mpfr_set_prec (x, 64);
  mpfr_set_str_binary (x, "0.1011001000011110000110000110001111101011000010001110011000000000");
  if (mpfr_can_round (x, 65, MPFR_RNDN, MPFR_RNDN, 54))
    {
      printf ("Error (3) in mpfr_can_round\n");
      exit (1);
    }

  mpfr_set_prec (x, 137);
  mpfr_set_str_binary (x, "-0.10111001101001010110011000110100111010011101101010010100101100001110000100111111011101010110001010111100100101110111100001000010000000000E-97");
  if (mpfr_can_round (x, 132, MPFR_RNDU, MPFR_RNDZ, 128) == 0)
    {
      printf ("Error (4) in mpfr_can_round\n");
      exit (1);
    }

  /* in the following, we can round but cannot determine the inexact flag */
  mpfr_set_prec (x, 86);
  mpfr_set_str_binary (x, "-0.11100100010011001111011010100111101010011000000000000000000000000000000000000000000000E-80");
  if (mpfr_can_round (x, 81, MPFR_RNDU, MPFR_RNDZ, 44) == 0)
    {
      printf ("Error (5) in mpfr_can_round\n");
      exit (1);
    }

  mpfr_set_prec (x, 62);
  mpfr_set_str (x, "0.ff4ca619c76ba69", 16, MPFR_RNDZ);
  for (i = 30; i < 99; i++)
    for (j = 30; j < 99; j++)
      {
        int r1, r2;
        for (r1 = 0; r1 < MPFR_RND_MAX ; r1++)
          for (r2 = 0; r2 < MPFR_RND_MAX ; r2++)
            mpfr_can_round (x, i, (mpfr_rnd_t) r1, (mpfr_rnd_t) r2, j); /* test for assertions */
      }

  mpfr_clear (x);

  check_round_p ();

  tests_end_mpfr ();
  return 0;
}
