pqc/external/flint-2.4.3/nmod_poly/test/t-hgcd.c

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2014-05-18 22:03:37 +00:00
/*=============================================================================
This file is part of FLINT.
FLINT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FLINT 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with FLINT; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
=============================================================================*/
/******************************************************************************
Copyright (C) 2011 William Hart
Copyright (C) 2011 Sebastian Pancratz
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "nmod_poly.h"
#include "ulong_extras.h"
#include "mpn_extras.h"
#define __mul(C, lenC, A, lenA, B, lenB) \
do { \
if ((lenA) != 0 && (lenB) != 0) \
{ \
if ((lenA) >= (lenB)) \
_nmod_poly_mul((C), (A), (lenA), (B), (lenB), mod); \
else \
_nmod_poly_mul((C), (B), (lenB), (A), (lenA), mod); \
(lenC) = (lenA) + (lenB) - 1; \
} \
else \
{ \
(lenC) = 0; \
} \
} while (0)
int
main(void)
{
int i, result;
FLINT_TEST_INIT(state);
flint_printf("hgcd....");
fflush(stdout);
/*
Find coprime polys, multiply by another poly
and check the GCD is that poly
*/
for (i = 0; i < 100 * flint_test_multiplier(); i++)
{
nmod_poly_t a, b, c, d, c1, d1, s, t;
mp_ptr M[4];
slong lenM[4];
slong sgnM;
mp_limb_t n = n_randprime(state, FLINT_BITS, 0);
nmod_poly_init(a, n);
nmod_poly_init(b, n);
nmod_poly_init(c, n);
nmod_poly_init(d, n);
nmod_poly_init(c1, n);
nmod_poly_init(d1, n);
nmod_poly_init(s, n);
nmod_poly_init(t, n);
do {
nmod_poly_randtest_not_zero(a, state, n_randint(state, 800) + 1);
nmod_poly_randtest_not_zero(b, state, n_randint(state, 800) + 1);
} while (a->length == b->length);
if (a->length < b->length)
nmod_poly_swap(a, b);
M[0] = _nmod_vec_init(a->length);
M[1] = _nmod_vec_init(a->length);
M[2] = _nmod_vec_init(a->length);
M[3] = _nmod_vec_init(a->length);
nmod_poly_fit_length(c, a->length);
nmod_poly_fit_length(d, b->length);
sgnM = _nmod_poly_hgcd(M, lenM,
c->coeffs, &(c->length), d->coeffs, &(d->length),
a->coeffs, a->length, b->coeffs, b->length, a->mod);
nmod_poly_fit_length(s, 2 * a->length);
nmod_poly_fit_length(t, 2 * a->length);
/* [c1,d1] := sgnM * M^{-1} [a,b] */
{
const nmod_t mod = a->mod;
MPN_SWAP(M[0], lenM[0], M[3], lenM[3]);
_nmod_vec_neg(M[1], M[1], lenM[1], mod);
_nmod_vec_neg(M[2], M[2], lenM[2], mod);
__mul(s->coeffs, s->length, M[0], lenM[0], a->coeffs, a->length);
__mul(t->coeffs, t->length, M[1], lenM[1], b->coeffs, b->length);
nmod_poly_add(c1, s, t);
__mul(s->coeffs, s->length, M[2], lenM[2], a->coeffs, a->length);
__mul(t->coeffs, t->length, M[3], lenM[3], b->coeffs, b->length);
nmod_poly_add(d1, s, t);
}
if (sgnM < 0)
{
nmod_poly_neg(c1, c1);
nmod_poly_neg(d1, d1);
}
result = (nmod_poly_equal(c, c1) && nmod_poly_equal(d, d1));
if (!result)
{
flint_printf("FAIL:\n");
flint_printf("a = "), nmod_poly_print(a), flint_printf("\n\n");
flint_printf("b = "), nmod_poly_print(b), flint_printf("\n\n");
flint_printf("c = "), nmod_poly_print(c), flint_printf("\n\n");
flint_printf("d = "), nmod_poly_print(d), flint_printf("\n\n");
flint_printf("c1 = "), nmod_poly_print(c1), flint_printf("\n\n");
flint_printf("d1 = "), nmod_poly_print(d1), flint_printf("\n\n");
abort();
}
nmod_poly_clear(a);
nmod_poly_clear(b);
nmod_poly_clear(c);
nmod_poly_clear(d);
nmod_poly_clear(c1);
nmod_poly_clear(d1);
nmod_poly_clear(s);
nmod_poly_clear(t);
_nmod_vec_clear(M[0]);
_nmod_vec_clear(M[1]);
_nmod_vec_clear(M[2]);
_nmod_vec_clear(M[3]);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}
#undef __mul