/*

 * Copyright (c) 2008-2024 Stefan Krah. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

#include <assert.h>

#include <stdio.h>

#include "bits.h"

#include "difradix2.h"

#include "fnt.h"

#include "mpdecimal.h"

#include "numbertheory.h"

/* Bignum: Fast transform for medium-sized coefficients */

/* forward transform, sign = -1 */

int

std_fnt(mpd_uint_t *a, mpd_size_t n, int modnum)

{

    struct fnt_params *tparams;

    assert(ispower2(n));

    assert(n >= 4);

    assert(n <= 3*MPD_MAXTRANSFORM_2N);

    if ((tparams = _mpd_init_fnt_params(n, -1, modnum)) == NULL) {

        return 0;

    }

    fnt_dif2(a, n, tparams);

    mpd_free(tparams);

    return 1;

}

/* reverse transform, sign = 1 */

int

std_inv_fnt(mpd_uint_t *a, mpd_size_t n, int modnum)

{

    struct fnt_params *tparams;

    assert(ispower2(n));

    assert(n >= 4);

    assert(n <= 3*MPD_MAXTRANSFORM_2N);

    if ((tparams = _mpd_init_fnt_params(n, 1, modnum)) == NULL) {

        return 0;

    }

    fnt_dif2(a, n, tparams);

    mpd_free(tparams);

    return 1;

}