mpir/tests/mpn/t-inv_div_q.c
2010-02-23 19:13:24 +00:00

131 lines
3.1 KiB
C

/* Test mpn_inv_div_q.
Copyright 2002 Free Software Foundation, Inc.
Copyright 2009 William Hart
This file is part of the MPIR Library.
The MPIR 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 MPIR 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 MPIR 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 "longlong.h"
#include "tests.h"
#if defined(_MSC_VER) || defined(__MINGW32__)
#define random rand
#endif
#define MAX_LIMBS 400
#define ITERS 10000
/* Check precomputed inverse division routine. */
void
check_inv_div_q (void)
{
mp_limb_t np[2*MAX_LIMBS];
mp_limb_t np2[2*MAX_LIMBS];
mp_limb_t rp[2*MAX_LIMBS+1];
mp_limb_t dp[MAX_LIMBS];
mp_limb_t qp[2*MAX_LIMBS];
mp_limb_t inv[MAX_LIMBS];
mp_limb_t cy;
mp_size_t nn, rn, dn, qn;
gmp_randstate_t rands;
int i, j, s;
gmp_randinit_default(rands);
for (i = 0; i < ITERS; i++)
{
dn = (random() % (MAX_LIMBS - 5)) + 6;
nn = (random() % (MAX_LIMBS-1)) + dn + 1;
mpn_rrandom (np, rands, nn);
mpn_rrandom (dp, rands, dn);
dp[dn-1] |= GMP_LIMB_HIGHBIT;
MPN_COPY(np2, np, nn);
mpn_invert(inv, dp, dn);
qn = nn - dn + 1;
qp[qn - 1] = mpn_inv_div_q(qp, np, nn, dp, dn, inv);
MPN_NORMALIZE(qp, qn);
if (qn)
{
if (qn >= dn) mpn_mul(rp, qp, qn, dp, dn);
else mpn_mul(rp, dp, dn, qp, qn);
rn = dn + qn;
MPN_NORMALIZE(rp, rn);
if (rn > nn)
{
printf("failed: q*d has too many limbs\n");
abort();
}
if (mpn_cmp(rp, np2, nn) > 0)
{
printf("failed: remainder negative\n");
abort();
}
mpn_sub(rp, np2, nn, rp, rn);
rn = nn;
MPN_NORMALIZE(rp, rn);
} else
{
rn = nn;
MPN_COPY(rp, np, nn);
}
s = (rn < dn) ? -1 : (rn > dn) ? 1 : mpn_cmp(rp, dp, dn);
if (s >= 0)
{
printf ("failed:\n");
printf ("nn = %lu, dn = %lu, qn = %lu, rn = %lu\n\n", nn, dn, qn, rn);
gmp_printf (" np: %Nx\n\n", np2, nn);
gmp_printf (" dp: %Nx\n\n", dp, dn);
gmp_printf (" qp: %Nx\n\n", qp, qn);
gmp_printf (" rp: %Nx\n\n", rp, rn);
abort ();
}
}
gmp_randclear(rands);
}
int
main (void)
{
tests_start ();
check_inv_div_q ();
tests_end ();
exit (0);
}