/* Test mpz_fib_ui and mpz_fib2_ui.

Copyright 2000, 2001 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP 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 GNU MP 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 MP Library; see the file COPYING.LIB.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */

#include <stdio.h>
#include <stdlib.h>
#include "gmp.h"
#include "gmp-impl.h"
#include "tests.h"


/* Usage: t-fib_ui [x|num]

   Run with no arguments, tests goes up to the initial value of "limit"
   below.  With a number argument tests are carried up that far, or with a
   literal "x" tests are continued without limit (this being only meant for
   development purposes).

   The size tests performed are designed to partially replicate what will be
   going on in mpz_fib_ui.  There's plenty of ASSERTs there, but of course
   they're not normally enabled.

   Misfeatures:

   The tests on MPN_FIB2_SIZE are a bit useless, since that macro includes a
   +2 for the internal purposes of mpn_fib2_ui.  It's probably better to
   give mpn_fib2_ui a run with assertion checking enabled.  */


#define MPZ_FIB_SIZE_FLOAT(n) \
  ((mp_size_t) ((n) * 0.6942419 / BITS_PER_MP_LIMB + 1))

int
main (int argc, char *argv[])
{
  unsigned long  n;
  unsigned long  limit = 100 * BITS_PER_MP_LIMB;
  mpz_t          want_fn, want_fn1, got_fn, got_fn1;

  tests_start ();
  mp_trace_base = -16;
  if (argc > 1 && argv[1][0] == 'x')
    limit = ULONG_MAX;
  else if (argc > 1)
    limit = atoi (argv[1]);

  /* start at n==0 */
  mpz_init_set_ui (want_fn1, 1);  /* F[-1] */
  mpz_init_set_ui (want_fn,  0);  /* F[0]   */
  mpz_init (got_fn);
  mpz_init (got_fn1);

  for (n = 0; n < limit; n++)
    {
      /* check our float formula seems right */
      if (MPZ_FIB_SIZE_FLOAT (n) < SIZ(want_fn))
        {
          printf ("MPZ_FIB_SIZE_FLOAT wrong at n=%lu\n", n);
          printf ("  MPZ_FIB_SIZE_FLOAT  %ld\n", MPZ_FIB_SIZE_FLOAT (n));
          printf ("  SIZ(want_fn)        %d\n", SIZ(want_fn));
          abort ();
        }

      /* check MPN_FIB2_SIZE seems right, compared to actual size and
         compared to our float formula */
      if (MPN_FIB2_SIZE (n) < MPZ_FIB_SIZE_FLOAT (n))
        {
          printf ("MPN_FIB2_SIZE wrong at n=%lu\n", n);
          printf ("  MPN_FIB2_SIZE       %ld\n", MPN_FIB2_SIZE (n));
          printf ("  MPZ_FIB_SIZE_FLOAT  %ld\n", MPZ_FIB_SIZE_FLOAT (n));
          abort ();
        }
      if (MPN_FIB2_SIZE (n) < SIZ(want_fn))
        {
          printf ("MPN_FIB2_SIZE wrong at n=%lu\n", n);
          printf ("  MPN_FIB2_SIZE  %ld\n", MPN_FIB2_SIZE (n));
          printf ("  SIZ(want_fn)   %d\n", SIZ(want_fn));
          abort ();
        }

      mpz_fib2_ui (got_fn, got_fn1, n);
      MPZ_CHECK_FORMAT (got_fn);
      MPZ_CHECK_FORMAT (got_fn1);
      if (mpz_cmp (got_fn, want_fn) != 0 || mpz_cmp (got_fn1, want_fn1) != 0)
        {
          printf ("mpz_fib2_ui(%lu) wrong\n", n);
          mpz_trace ("want fn ", want_fn);
          mpz_trace ("got  fn ",  got_fn);
          mpz_trace ("want fn1", want_fn1);
          mpz_trace ("got  fn1",  got_fn1);
          abort ();
        }

      mpz_fib_ui (got_fn, n);
      MPZ_CHECK_FORMAT (got_fn);
      if (mpz_cmp (got_fn, want_fn) != 0)
        {
          printf ("mpz_fib_ui(%lu) wrong\n", n);
          mpz_trace ("want fn", want_fn);
          mpz_trace ("got  fn", got_fn);
          abort ();
        }

      mpz_add (want_fn1, want_fn1, want_fn);  /* F[n+1] = F[n] + F[n-1] */
      mpz_swap (want_fn1, want_fn);
    }

  mpz_clear (want_fn);
  mpz_clear (want_fn1);
  mpz_clear (got_fn);
  mpz_clear (got_fn1);

  tests_end ();
  exit (0);
}
