/* Test file for mpfr_ui_pow and mpfr_ui_pow_ui.

Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 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 <limits.h>

#include "mpfr-test.h"

static void
test1 (void)
{
  mpfr_t x, y, z, a;
  int res1, res2;

  mpfr_init2 (x, 32);
  mpfr_init2 (y, 65);
  mpfr_init2 (z, 17);
  mpfr_init2 (a, 17);

  mpfr_set_str_binary (x, "-0.101110001001011011011e-9");
  mpfr_ui_pow (y, 7, x, GMP_RNDN);

  mpfr_set_prec (x, 40);
  mpfr_set_str_binary (x, "-0.1100101100101111011001010010110011110110E-1");
  mpfr_set_prec (y, 74);
  mpfr_ui_pow (y, 8, x, GMP_RNDN);
  mpfr_set_prec (x, 74);
  mpfr_set_str_binary (x, "0.11100000010100111101000011111011011010011000011000101011010011010101000011E-1");
  if (mpfr_cmp (x, y))
    {
      printf ("Error for input of 40 bits, output of 74 bits\n");
      exit (1);
    }

  /* Check for ui_pow_ui */
  mpfr_ui_pow_ui (x, 0, 1, GMP_RNDN);
  MPFR_ASSERTN(mpfr_cmp_ui (x, 0) == 0 && MPFR_IS_POS (x));
  mpfr_ui_pow_ui (x, 0, 4, GMP_RNDN);
  MPFR_ASSERTN(mpfr_cmp_ui (x, 0) == 0 && MPFR_IS_POS (x));
  res1 = mpfr_ui_pow_ui (z, 17, 42, GMP_RNDD);
  mpfr_set_ui (x, 17, GMP_RNDN);
  mpfr_set_ui (y, 42, GMP_RNDN);
  res2 = mpfr_pow (a, x, y, GMP_RNDD);
  if (mpfr_cmp (z, a) || res1 != res2)
    {
      printf ("Error for ui_pow_ui for 17^42\n"
              "Inexact1 = %d Inexact2 = %d\n", res1, res2);
      mpfr_dump (z);
      mpfr_dump (a);
      exit (1);
    }
  mpfr_set_prec (x, 2);
  mpfr_ui_pow_ui (x, 65537, 65535, GMP_RNDN);
  if (mpfr_cmp_str (x, "0.11E1048562", 2, GMP_RNDN) != 0)
    {
      printf ("Error for ui_pow_ui for 65537 ^65535 with 2 bits of precision\n");
      mpfr_dump (x);
      exit (1);
    }
  mpfr_clear (x);
  mpfr_clear (y);
  mpfr_clear (z);
  mpfr_clear (a);
}

static void
check1 (mpfr_ptr x, mp_prec_t prec, unsigned long nt, mp_rnd_t rnd)
{
  mpfr_t y, z, t;
  int inexact, compare, compare2;
  mp_prec_t yprec;
  mp_exp_t err;

  yprec = prec + 10;

  mpfr_init (y);
  mpfr_init (z);
  mpfr_init (t);
  mpfr_set_prec (y, yprec);
  mpfr_set_prec (z, prec);
  mpfr_set_prec (t, prec);

  compare = mpfr_ui_pow (y, nt, x, rnd);
  err = (rnd == GMP_RNDN) ? yprec + 1 : yprec;
  if (mpfr_can_round (y, err, rnd, rnd, prec))
    {
      mpfr_set (t, y, rnd);
      inexact = mpfr_ui_pow (z, nt, x, rnd);
      if (mpfr_cmp (t, z))
        {
          printf ("results differ for x=");
          mpfr_out_str (stdout, 2, prec, x, GMP_RNDN);
          printf (" n=%lu", nt);
          printf (" prec=%u rnd_mode=%s\n", (unsigned) prec,
                  mpfr_print_rnd_mode (rnd));
          printf ("got      ");
          mpfr_out_str (stdout, 2, prec, z, GMP_RNDN);
          puts ("");
          printf ("expected ");
          mpfr_out_str (stdout, 2, prec, t, GMP_RNDN);
          puts ("");
          printf ("approx  ");
          mpfr_print_binary (y);
          puts ("");
          exit (1);
        }
      compare2 = mpfr_cmp (t, y);
      /* if rounding to nearest, cannot know the sign of t - f(x)
         because of composed rounding: y = o(f(x)) and t = o(y) */
      if ((rnd != GMP_RNDN) && (compare * compare2 >= 0))
        compare = compare + compare2;
      else
        compare = inexact; /* cannot determine sign(t-f(x)) */
      if (((inexact == 0) && (compare != 0)) ||
          ((inexact > 0) && (compare <= 0)) ||
          ((inexact < 0) && (compare >= 0)))
        {
          printf ("Wrong inexact flag for rnd=%s: expected %d, got %d\n",
                  mpfr_print_rnd_mode (rnd), compare, inexact);
          printf ("x="); mpfr_print_binary (x); puts ("");
          printf ("y="); mpfr_print_binary (y); puts ("");
          printf ("t="); mpfr_print_binary (t); puts ("");
          exit (1);
        }
    }

  mpfr_clear (y);
  mpfr_clear (z);
  mpfr_clear (t);
}

int
main (int argc, char *argv[])
{
  mpfr_t x, y;
  unsigned long int n;

  tests_start_mpfr ();

  mpfr_init (x);
  mpfr_init (y);

  n = randlimb ();

  MPFR_SET_INF(x);
  mpfr_ui_pow (y, n, x, GMP_RNDN);
  if(!MPFR_IS_INF(y))
    {
      printf ("evaluation of function in INF does not return INF\n");
      exit (1);
    }

  MPFR_CHANGE_SIGN(x);
  mpfr_ui_pow (y, n, x, GMP_RNDN);
  if(!MPFR_IS_ZERO(y))
    {
      printf ("evaluation of function in -INF does not return 0");
      exit (1);
    }

  MPFR_SET_NAN(x);
  mpfr_ui_pow (y, n, x, GMP_RNDN);
  if(!MPFR_IS_NAN(y))
    {
      printf ("evaluation of function in NAN does not return NAN");
      exit (1);
    }

  test1 ();

  {
  mpfr_t z, t;
  mp_prec_t prec;
  mp_rnd_t rnd;
  unsigned int n;

  mp_prec_t p0=2, p1=100;
  unsigned int N=20;

  mpfr_init2 (z, 38);
  mpfr_init2 (t, 6);

  /* check exact power */
  mpfr_set_str_binary (t, "0.110000E5");
  mpfr_ui_pow (z, 3, t, GMP_RNDN);

  mpfr_set_prec (x, 2);
  mpfr_set_prec (y, 2);
  mpfr_set_str (x, "-0.5", 10, GMP_RNDZ);
  mpfr_ui_pow (y, 4, x, GMP_RNDD);
  if (mpfr_cmp_ui_2exp(y, 1, -1))
    {
      fprintf (stderr, "Error for 4^(-0.5), prec=2, GMP_RNDD\n");
      fprintf (stderr, "expected 0.5, got ");
      mpfr_out_str (stderr, 2, 0, y, GMP_RNDN);
      fprintf (stderr, "\n");
      exit (1);
    }

  /* problem found by Kevin on spe175.testdrive.compaq.com
     (03 Sep 2003) */
  mpfr_set_prec (x, 2);
  mpfr_set_prec (y, 2);
  mpfr_set_str (x, "0.5", 10, GMP_RNDN);
  mpfr_ui_pow (y, 398441521, x, GMP_RNDN);
  if (mpfr_cmp_ui_2exp(y, 1, 14))
    {
      fprintf (stderr, "Error for 398441521^(0.5), prec=2, GMP_RNDN\n");
      fprintf (stderr, "expected 1.0e14, got ");
      mpfr_out_str (stderr, 2, 0, y, GMP_RNDN);
      fprintf (stderr, "\n");
      exit (1);
    }

  mpfr_clear (z);
  mpfr_clear (t);

  mpfr_set_prec (x, 2);
  mpfr_set_str (x, "0.5", 10, GMP_RNDN);
  check1 (x, 2, 398441521, GMP_RNDN);  /* 398441521 = 19961^2 */

  /* generic test */
  for (prec = p0; prec <= p1; prec++)
    {
      mpfr_set_prec (x, prec);
      for (n=0; n<N; n++)
        {
          int nt;
          nt = randlimb () & INT_MAX;
          mpfr_random (x);
          rnd = (mp_rnd_t) RND_RAND ();
          check1 (x, prec, nt, rnd);
        }
    }
  }

  mpfr_clear (x);
  mpfr_clear (y);

  tests_end_mpfr ();
  return 0;
}