mpir/tests/mpn/t-perfsqr.c

/* Test mpn_perfect_square_p data.

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

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

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

#define PERFSQR_MOD_MASK   ((CNST_LIMB(1) << PERFSQR_MOD_BITS) - 1)

void
check_mod_2 (mp_limb_t d, mp_limb_t inv, mp_limb_t got_hi, mp_limb_t got_lo)
{
  int        want[2*GMP_LIMB_BITS], got;
  unsigned   r, idx;
  mp_limb_t  q;

  ASSERT_ALWAYS (d <= numberof (want));
  ASSERT_ALWAYS (((inv * d) & PERFSQR_MOD_MASK) == 1);
  ASSERT_ALWAYS (MP_LIMB_T_MAX / d >= PERFSQR_MOD_MASK);

  /* the squares mod d */
  for (r = 0; r < d; r++)
    want[r] = 0;
  for (r = 0; r < d; r++)
    want[(r*r)%d] = 1;

  /* for each remainder mod d, expect the table data to correctly identify
     it as a residue or non-residue */
  for (r = 0; r < d; r++)
    {
      /* as per PERFSQR_MOD_IDX */
      q = ((r) * (inv)) & PERFSQR_MOD_MASK;
      idx = (q * (d)) >> PERFSQR_MOD_BITS;

      if (idx >= GMP_LIMB_BITS)
        got = (got_hi >> (idx - GMP_LIMB_BITS)) & 1;
      else
        got = (got_lo >> idx) & 1;

      if (got != want[r])
        {
          printf ("Wrong generated data\n");
          printf ("  d=%u\n", (unsigned) d);
          printf ("  r=%u\n", r);
          printf ("  idx=%u\n", idx);
          printf ("  got  %d\n", got);
          printf ("  want %d\n", want[r]);
          abort ();
        }
    }
}

/* Check the generated data in perfsqr.h. */
void
check_mod (void)
{
#define PERFSQR_MOD_34(r, up, usize)       { r = 0; } /* so r isn't unused */
#define PERFSQR_MOD_PP(r, up, usize)       { r = 0; }
#define PERFSQR_MOD_1(r, d, inv, mask)     check_mod_2 (d, inv, CNST_LIMB(0), mask)
#define PERFSQR_MOD_2(r, d, inv, mhi, mlo) check_mod_2 (d, inv, mhi, mlo)

  PERFSQR_MOD_TEST (dummy, dummy);
}

/* Check PERFSQR_PP, if in use. */
void
check_pp (void)
{
#ifdef PERFSQR_PP
  ASSERT_ALWAYS_LIMB (PERFSQR_PP);
  ASSERT_ALWAYS_LIMB (PERFSQR_PP_NORM);
  ASSERT_ALWAYS_LIMB (PERFSQR_PP_INVERTED);

  /* preinv stuff only for nails==0 */
  if (GMP_NAIL_BITS == 0)
    {
      ASSERT_ALWAYS (PERFSQR_PP_NORM
                     == PERFSQR_PP << refmpn_count_leading_zeros (PERFSQR_PP));
      ASSERT_ALWAYS (PERFSQR_PP_INVERTED
                     == refmpn_invert_limb (PERFSQR_PP_NORM));
    }
#endif
}

int
main (void)
{
  tests_start ();

  check_mod ();
  check_pp ();

  tests_end ();
  exit (0);
}