t-cdiv_ui.c

a very popular packet of cryptography tools,it encloses the most common used algorithm and protocols

/* Test mpz_abs, mpz_add, mpz_cmp, mpz_cmp_ui, mpz_cdiv_qr_ui, mpz_cdiv_q_ui,
   mpz_cdiv_r_ui, , mpz_cdiv_ui, mpz_mul_ui.

Copyright 1993, 1994, 1996, 2000, 2001, 2002 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"

void dump_abort _PROTO ((char *, mpz_t, unsigned long));
void debug_mp _PROTO ((mpz_t, int));

int
main (int argc, char **argv)
{
  mpz_t dividend;
  mpz_t quotient, remainder;
  mpz_t quotient2, remainder2;
  mpz_t temp;
  mp_size_t dividend_size;
  unsigned long divisor;
  int i;
  int reps = 10000;
  gmp_randstate_ptr rands;
  mpz_t bs;
  unsigned long bsi, size_range;
  unsigned long r_rq, r_q, r_r, r;

  tests_start ();
  rands = RANDS;

  mpz_init (bs);

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

  mpz_init (dividend);
  mpz_init (quotient);
  mpz_init (remainder);
  mpz_init (quotient2);
  mpz_init (remainder2);
  mpz_init (temp);

  for (i = 0; i < reps; i++)
    {
      mpz_urandomb (bs, rands, 32);
      size_range = mpz_get_ui (bs) % 10 + 2; /* 0..2047 bit operands */

      do
	{
	  mpz_rrandomb (bs, rands, 64);
	  divisor = mpz_get_ui (bs);
	}
      while (divisor == 0);

      mpz_urandomb (bs, rands, size_range);
      dividend_size = mpz_get_ui (bs);
      mpz_rrandomb (dividend, rands, dividend_size);

      mpz_urandomb (bs, rands, 2);
      bsi = mpz_get_ui (bs);
      if ((bsi & 1) != 0)
	mpz_neg (dividend, dividend);

      /* printf ("%ld\n", SIZ (dividend)); */

      r_rq = mpz_cdiv_qr_ui (quotient, remainder, dividend, divisor);
      r_q = mpz_cdiv_q_ui (quotient2, dividend, divisor);
      r_r = mpz_cdiv_r_ui (remainder2, dividend, divisor);
      r = mpz_cdiv_ui (dividend, divisor);

      /* First determine that the quotients and remainders computed
	 with different functions are equal.  */
      if (mpz_cmp (quotient, quotient2) != 0)
	dump_abort ("quotients from mpz_cdiv_qr_ui and mpz_cdiv_q_ui differ",
		    dividend, divisor);
      if (mpz_cmp (remainder, remainder2) != 0)
	dump_abort ("remainders from mpz_cdiv_qr_ui and mpz_cdiv_r_ui differ",
		    dividend, divisor);

      /* Check if the sign of the quotient is correct.  */
      if (mpz_cmp_ui (quotient, 0) != 0)
	if ((mpz_cmp_ui (quotient, 0) < 0)
	    != (mpz_cmp_ui (dividend, 0) < 0))
	dump_abort ("quotient sign wrong", dividend, divisor);

      /* Check if the remainder has the opposite sign as the (positive) divisor
	 (quotient rounded towards minus infinity).  */
      if (mpz_cmp_ui (remainder, 0) != 0)
	if (mpz_cmp_ui (remainder, 0) > 0)
	  dump_abort ("remainder sign wrong", dividend, divisor);

      mpz_mul_ui (temp, quotient, divisor);
      mpz_add (temp, temp, remainder);
      if (mpz_cmp (temp, dividend) != 0)
	dump_abort ("n mod d != n - [n/d]*d", dividend, divisor);

      mpz_abs (remainder, remainder);
      if (mpz_cmp_ui (remainder, divisor) >= 0)
	dump_abort ("remainder greater than divisor", dividend, divisor);

      if (mpz_cmp_ui (remainder, r_rq) != 0)
	dump_abort ("remainder returned from mpz_cdiv_qr_ui is wrong",
		    dividend, divisor);
      if (mpz_cmp_ui (remainder, r_q) != 0)
	dump_abort ("remainder returned from mpz_cdiv_q_ui is wrong",
		    dividend, divisor);
      if (mpz_cmp_ui (remainder, r_r) != 0)
	dump_abort ("remainder returned from mpz_cdiv_r_ui is wrong",
		    dividend, divisor);
      if (mpz_cmp_ui (remainder, r) != 0)
	dump_abort ("remainder returned from mpz_cdiv_ui is wrong",
		    dividend, divisor);
    }

  mpz_clear (bs);
  mpz_clear (dividend);
  mpz_clear (quotient);
  mpz_clear (remainder);
  mpz_clear (quotient2);
  mpz_clear (remainder2);
  mpz_clear (temp);

  tests_end ();
  exit (0);
}

void
dump_abort (char *str, mpz_t dividend, unsigned long divisor)
{
  fprintf (stderr, "ERROR: %s\n", str);
  fprintf (stderr, "dividend = "); debug_mp (dividend, -16);
  fprintf (stderr, "divisor  = %lX\n", divisor);
  abort();
}

void
debug_mp (mpz_t x, int base)
{
  mpz_out_str (stderr, base, x); fputc ('\n', stderr);
}