pqc/external/flint-2.4.3/arith/test/t-cyclotomic_polynomial.c
2014-05-24 23:16:06 +02:00

146 lines
3.9 KiB
C

/*=============================================================================
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 Fredrik Johansson
******************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
#include "flint.h"
#include "arith.h"
#include "fmpz.h"
#include "fmpz_poly.h"
#include "ulong_extras.h"
void cyclotomic_naive(fmpz_poly_t poly, ulong n)
{
fmpz_poly_t t;
slong d;
fmpz_poly_init(t);
fmpz_poly_set_ui(poly, UWORD(1));
for (d = 1; d <= n; d++)
{
if (n % d == 0)
{
if (n_moebius_mu(n / d) == 1)
{
fmpz_poly_zero(t);
fmpz_poly_set_coeff_si(t, d, 1);
fmpz_poly_set_coeff_si(t, 0, -1);
fmpz_poly_mul(poly, poly, t);
}
}
}
for (d = 1; d <= n; d++)
{
if (n % d == 0)
{
if (n_moebius_mu(n / d) == -1)
{
fmpz_poly_zero(t);
fmpz_poly_set_coeff_si(t, d, 1);
fmpz_poly_set_coeff_si(t, 0, -1);
fmpz_poly_div(poly, poly, t);
}
}
}
fmpz_poly_clear(t);
}
int main()
{
fmpz_poly_t A, B;
slong n;
FLINT_TEST_INIT(state);
flint_printf("cyclotomic_polynomial....");
fflush(stdout);
for (n = 0; n <= 1000; n++)
{
fmpz_poly_init(A);
fmpz_poly_init(B);
arith_cyclotomic_polynomial(A, n);
cyclotomic_naive(B, n);
if (!fmpz_poly_equal(A, B))
{
flint_printf("FAIL: wrong value of Phi_%wd(x)\n", n);
flint_printf("Computed:\n");
fmpz_poly_print_pretty(A, "x");
flint_printf("\n\nExpected:\n");
fmpz_poly_print_pretty(B, "x");
flint_printf("\n\n");
abort();
}
fmpz_poly_clear(A);
fmpz_poly_clear(B);
}
/* We verify the first value that does not fit on 32 bits.
This exercises the slow path at least on a 32 bit system.
Testing the 64 bit value is a bit too much to do by default
as it requires ~2 GB of memory and takes a few minutes. */
{
fmpz_t h, ref;
const ulong nn = UWORD(10163195);
/* const ulong nn = UWORD(169828113); 64-bit case */
fmpz_init(h);
fmpz_init(ref);
fmpz_set_str(ref, "1376877780831", 10);
/* fmpz_set_str(ref, "31484567640915734941", 10); 64-bit case */
fmpz_poly_init(A);
arith_cyclotomic_polynomial(A, UWORD(10163195));
fmpz_poly_height(h, A);
if (!fmpz_equal(h, ref))
{
flint_printf("Bad computation of Phi_%wd(x)\n", nn);
flint_printf("Computed height:\n");
fmpz_print(h);
flint_printf("\nExpected height:\n");
fmpz_print(ref);
flint_printf("\n\n");
abort();
}
fmpz_poly_clear(A);
fmpz_clear(h);
fmpz_clear(ref);
}
FLINT_TEST_CLEANUP(state);
flint_printf("PASS\n");
return 0;
}