/* Test mpz_pow_ui and mpz_ui_pow_ui.

Copyright 1997, 1999, 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., 51 Franklin Street, Fifth Floor, Boston,
MA 02110-1301, USA.
*/

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

#include "gmp.h"
#include "gmp-impl.h"
#include "tests.h"


void
check_one (mpz_srcptr want, mpz_srcptr base, unsigned long exp)
{
  mpz_t  got;

  mpz_init (got);

  mpz_pow_ui (got, base, exp);
  if (mpz_cmp (got, want))
    {
      printf ("mpz_pow_ui wrong\n");
      mpz_trace ("  base", base);
      printf    ("  exp = %lu (0x%lX)\n", exp, exp);
      mpz_trace ("  got ", got);
      mpz_trace ("  want", want);
      abort ();
    }

  mpz_set (got, base);
  mpz_pow_ui (got, got, exp);
  if (mpz_cmp (got, want))
    {
      printf ("mpz_pow_ui wrong\n");
      mpz_trace ("  base", base);
      printf    ("  exp = %lu (0x%lX)\n", exp, exp);
      mpz_trace ("  got ", got);
      mpz_trace ("  want", want);
      abort ();
    }

  if (mpz_fits_ulong_p (base))
    {
      unsigned long  base_u = mpz_get_ui (base);
      mpz_ui_pow_ui (got, base_u, exp);
      if (mpz_cmp (got, want))
        {
          printf    ("mpz_ui_pow_ui wrong\n");
          printf    ("  base=%lu (0x%lX)\n", base_u, base_u);
          printf    ("  exp = %lu (0x%lX)\n", exp, exp);
          mpz_trace ("  got ", got);
          mpz_trace ("  want", want);
          abort ();
        }
    }

  mpz_clear (got);
}

void
check_base (mpz_srcptr base)
{
  unsigned long  exp;
  mpz_t          want;

  mpz_init (want);
  mpz_set_ui (want, 1L);

  for (exp = 0; exp < 20; exp++)
    {
      check_one (want, base, exp);
      mpz_mul (want, want, base);
    }

  mpz_clear (want);
}

void
check_various (void)
{
  static const struct {
    const char *base;
  } data[] = {
    { "0" },
    { "1" },
    { "2" },
    { "3" },
    { "4" },
    { "5" },
    { "6" },
    { "10" },
    { "15" },
    { "16" },

    { "0x1F" },
    { "0xFF" },
    { "0x1001" },
    { "0xFFFF" },
    { "0x10000001" },
    { "0x1000000000000001" },

    /* actual size closest to estimate */
    { "0xFFFFFFFF" },
    { "0xFFFFFFFFFFFFFFFF" },

    /* same after rshift */
    { "0xFFFFFFFF0" },
    { "0xFFFFFFFF00" },
    { "0xFFFFFFFFFFFFFFFF0" },
    { "0xFFFFFFFFFFFFFFFF00" },

    /* change from 2 limbs to 1 after rshift */
    { "0x180000000" },
    { "0x18000000000000000" },

    /* change from 3 limbs to 2 after rshift */
    { "0x18000000100000000" },
    { "0x180000000000000010000000000000000" },

    /* handling of absolute value */
    { "-0x80000000" },
    { "-0x8000000000000000" },

    /* low zero limb, and size>2, checking argument overlap detection */
    { "0x3000000000000000300000000000000030000000000000000" },
  };

  mpz_t  base;
  int    i;

  mpz_init (base);

  for (i = 0; i < numberof (data); i++)
    {
      mpz_set_str_or_abort (base, data[i].base, 0);
      check_base (base);
    }

  mpz_clear (base);
}

void
check_random (int reps)
{
  mpz_t              base, want;
  mp_size_t          base_size;
  int                i;
  unsigned long      size_range, exp;
  gmp_randstate_ptr  rands = RANDS;
  
  mpz_init (base);
  mpz_init (want);

  for (i = 0; i < reps; i++)
    {
      /* exponentially random 0 to 2^13 bits for base */
      mpz_urandomb (want, rands, 32);
      size_range = mpz_get_ui (want) % 12 + 2;
      mpz_urandomb (want, rands, size_range);
      base_size = mpz_get_ui (want);
      mpz_rrandomb (base, rands, base_size);

      /* randomly signed base */
      mpz_urandomb (want, rands, 2);
      if ((mpz_get_ui (want) & 1) != 0)
	mpz_neg (base, base);

      /* random 5 bits for exponent */
      mpz_urandomb (want, rands, 5L);
      exp = mpz_get_ui (want);

      refmpz_pow_ui (want, base, exp);
      check_one (want, base, exp);
    }

  mpz_clear (base);
  mpz_clear (want);
}

int
main (int argc, char **argv)
{
  int reps = 500;

  /* dummy call to drag in refmpn.o for testing mpz/n_pow_ui.c with
     refmpn_mul_2 */
  refmpn_zero_p (NULL, (mp_size_t) 0);

  tests_start ();
  mp_trace_base = -16;

  if (argc == 2)
     reps = atoi (argv[1]);

  check_various ();
  check_random (reps);

  tests_end ();
  exit (0);
}
