/* tsum -- test file for the list summation function

Copyright 2004, 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 <stdlib.h>
#include <stdio.h>
#include "mpfr-test.h"

static int
check_is_sorted (unsigned long n, mpfr_srcptr *perm)
{
  unsigned long i;

  for (i = 0; i < n - 1; i++)
    if (MPFR_GET_EXP(perm[i]) < MPFR_GET_EXP(perm[i+1]))
      return 0;
  return 1;
}

static int
sum_tab (mpfr_ptr ret, mpfr_t *tab, unsigned long n, mp_rnd_t rnd)
{
  mpfr_ptr *tabtmp;
  unsigned long i;
  int inexact;
  MPFR_TMP_DECL(marker);

  MPFR_TMP_MARK(marker);
  tabtmp = (mpfr_ptr *) MPFR_TMP_ALLOC(n * sizeof(mpfr_srcptr));
  for (i = 0; i < n; i++)
    tabtmp[i] = tab[i];

  inexact = mpfr_sum (ret, tabtmp, n, rnd);
  MPFR_TMP_FREE(marker);
  return inexact;
}


static mp_prec_t
get_prec_max (mpfr_t *tab, unsigned long n, mp_prec_t f)
{
  mp_prec_t res;
  mp_exp_t min, max;
  unsigned long i;

  for (i = 0; MPFR_IS_ZERO (tab[i]); i++)
    MPFR_ASSERTD (i < n);
  min = max = MPFR_GET_EXP(tab[i]);
  for (i++; i < n; i++)
    {
      if (!MPFR_IS_ZERO (tab[i])) {
        if (MPFR_GET_EXP(tab[i]) > max)
          max = MPFR_GET_EXP(tab[i]);
        if (MPFR_GET_EXP(tab[i]) < min)
          min = MPFR_GET_EXP(tab[i]);
      }
    }
  res = max - min;
  res += f;
  res += __gmpfr_ceil_log2 (n) + 1;
  return res;
}


static void
algo_exact (mpfr_t somme, mpfr_t *tab, unsigned long n, mp_prec_t f)
{
  unsigned long i;
  mp_prec_t prec_max;

  prec_max = get_prec_max(tab, n, f);
  mpfr_set_prec (somme, prec_max);
  mpfr_set_ui (somme, 0, GMP_RNDN);
  for (i = 0; i < n; i++)
    {
      if (mpfr_add(somme, somme, tab[i], GMP_RNDN))
        {
          printf ("FIXME: algo_exact is buggy.\n");
          exit (1);
        }
    }
}

/* Test the sorting function */
static void
test_sort (mp_prec_t f, unsigned long n)
{
  mpfr_t *tab;
  mpfr_ptr *tabtmp;
  mpfr_srcptr *perm;
  unsigned long i;

  /* Init stuff */
  tab = (mpfr_t *) malloc (n * sizeof(mpfr_t));
  for (i = 0; i < n; i++)
    mpfr_init2 (tab[i], f);
  tabtmp = (mpfr_ptr *) malloc (n * sizeof(mpfr_ptr));
  perm = (mpfr_srcptr *) malloc (n * sizeof(mpfr_srcptr));

  for (i = 0; i < n; i++)
    {
      mpfr_random (tab[i]);
      tabtmp[i] = tab[i];
    }

  mpfr_sum_sort ((mpfr_srcptr *)tabtmp, n, perm);

  if (check_is_sorted (n, perm) == 0)
    {
      printf ("mpfr_sum_sort incorrect.\n");
      for (i = 0; i < n; i++)
        mpfr_dump (perm[i]);
      exit (1);
    }

  /* Clear stuff */
  for (i = 0; i < n; i++)
    mpfr_clear (tab[i]);
  free (tabtmp);
  free (perm);
  free (tab);
}

static void
test_sum (mp_prec_t f, unsigned long n)
{
  mpfr_t sum, real_sum, real_non_rounded;
  mpfr_t *tab;
  unsigned long i;
  int rnd_mode;

  /* Init */
  tab = (mpfr_t *) malloc (n * sizeof(mpfr_t));
  for (i = 0; i < n; i++)
    mpfr_init2 (tab[i], f);
  mpfr_inits2 (f, sum, real_sum, real_non_rounded, (void *) 0);

  /* First Uniform */
  for (i = 0; i < n; i++)
    mpfr_random (tab[i]);
  algo_exact (real_non_rounded, tab, n, f);
  for (rnd_mode = 0; rnd_mode < GMP_RND_MAX; rnd_mode++)
    {
      sum_tab (sum, tab, n, (mp_rnd_t) rnd_mode);
      mpfr_set (real_sum, real_non_rounded, (mp_rnd_t) rnd_mode);
      if (mpfr_cmp (real_sum, sum) != 0)
        {
          printf ("mpfr_sum incorrect.\n");
          mpfr_dump (real_sum);
          mpfr_dump (sum);
          exit (1);
        }
    }

  /* Then non uniform */
  for (i = 0; i < n; i++)
    {
      mpfr_random (tab[i]);
      mpfr_set_exp (tab[i], randlimb () %1000);
    }
  algo_exact (real_non_rounded, tab, n, f);
  for (rnd_mode = 0; rnd_mode < GMP_RND_MAX; rnd_mode++)
    {
      sum_tab (sum, tab, n, (mp_rnd_t) rnd_mode);
      mpfr_set (real_sum, real_non_rounded, (mp_rnd_t) rnd_mode);
      if (mpfr_cmp (real_sum, sum) != 0)
        {
          printf ("mpfr_sum incorrect.\n");
          mpfr_dump (real_sum);
          mpfr_dump (sum);
          exit (1);
        }
    }

  /* Clear stuff */
  for (i = 0; i < n; i++)
    mpfr_clear (tab[i]);
  mpfr_clears (sum, real_sum, real_non_rounded, (void *) 0);
  free (tab);
}

static
void check_special (void)
{
  mpfr_t tab[3], r;
  mpfr_ptr tabp[3];
  int i;

  mpfr_inits (tab[0], tab[1], tab[2], r, (void *) 0);
  tabp[0] = tab[0];
  tabp[1] = tab[1];
  tabp[2] = tab[2];

  i = mpfr_sum (r, tabp, 0, GMP_RNDN);
  if (!MPFR_IS_ZERO (r) || !MPFR_IS_POS (r) || i != 0)
    {
      printf ("Special case n==0 failed!\n");
      exit (1);
    }

  mpfr_set_ui (tab[0], 42, GMP_RNDN);
  i = mpfr_sum (r, tabp, 1, GMP_RNDN);
  if (mpfr_cmp_ui (r, 42) || i != 0)
    {
      printf ("Special case n==1 failed!\n");
      exit (1);
    }

  mpfr_set_ui (tab[1], 17, GMP_RNDN);
  MPFR_SET_NAN (tab[2]);
  i = mpfr_sum (r, tabp, 3, GMP_RNDN);
  if (!MPFR_IS_NAN (r) || i != 0)
    {
      printf ("Special case NAN failed!\n");
      exit (1);
    }

  MPFR_SET_INF (tab[2]);
  MPFR_SET_POS (tab[2]);
  i = mpfr_sum (r, tabp, 3, GMP_RNDN);
  if (!MPFR_IS_INF (r) || !MPFR_IS_POS (r) || i != 0)
    {
      printf ("Special case +INF failed!\n");
      exit (1);
    }

  MPFR_SET_INF (tab[2]);
  MPFR_SET_NEG (tab[2]);
  i = mpfr_sum (r, tabp, 3, GMP_RNDN);
  if (!MPFR_IS_INF (r) || !MPFR_IS_NEG (r) || i != 0)
    {
      printf ("Special case -INF failed!\n");
      exit (1);
    }

  MPFR_SET_ZERO (tab[1]);
  i = mpfr_sum (r, tabp, 2, GMP_RNDN);
  if (mpfr_cmp_ui (r, 42) || i != 0)
    {
      printf ("Special case 42+0 failed!\n");
      exit (1);
    }

  MPFR_SET_NAN (tab[0]);
  i = mpfr_sum (r, tabp, 3, GMP_RNDN);
  if (!MPFR_IS_NAN (r) || i != 0)
    {
      printf ("Special case NAN+0+-INF failed!\n");
      exit (1);
    }

  mpfr_set_inf (tab[0], 1);
  mpfr_set_ui  (tab[1], 59, GMP_RNDN);
  mpfr_set_inf (tab[2], -1);
  i = mpfr_sum (r, tabp, 3, GMP_RNDN);
  if (!MPFR_IS_NAN (r) || i != 0)
    {
      printf ("Special case +INF + 59 +-INF failed!\n");
      exit (1);
    }

  mpfr_clears (tab[0], tab[1], tab[2], r, (void *) 0);
}


int
main (void)
{
  mp_prec_t p;
  unsigned long n;

  tests_start_mpfr ();

  check_special ();
  test_sort (1764, 1026);
  for (p = 2 ; p < 444 ; p += 17)
    for (n = 2 ; n < 1026 ; n += 42 + p)
      test_sum (p, n);

  tests_end_mpfr ();
  return 0;
}