80 lines
2.3 KiB
C
80 lines
2.3 KiB
C
/*
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* Copyright (c) 2008-2020 Stefan Krah. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "mpdecimal.h"
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#include <assert.h>
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#include <stdio.h>
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#include "bits.h"
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#include "difradix2.h"
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#include "fnt.h"
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#include "numbertheory.h"
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/* Bignum: Fast transform for medium-sized coefficients. */
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/* forward transform, sign = -1 */
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int
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std_fnt(mpd_uint_t *a, mpd_size_t n, int modnum)
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{
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struct fnt_params *tparams;
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assert(ispower2(n));
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assert(n >= 4);
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assert(n <= 3*MPD_MAXTRANSFORM_2N);
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if ((tparams = _mpd_init_fnt_params(n, -1, modnum)) == NULL) {
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return 0;
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}
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fnt_dif2(a, n, tparams);
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mpd_free(tparams);
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return 1;
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}
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/* reverse transform, sign = 1 */
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int
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std_inv_fnt(mpd_uint_t *a, mpd_size_t n, int modnum)
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{
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struct fnt_params *tparams;
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assert(ispower2(n));
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assert(n >= 4);
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assert(n <= 3*MPD_MAXTRANSFORM_2N);
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if ((tparams = _mpd_init_fnt_params(n, 1, modnum)) == NULL) {
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return 0;
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}
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fnt_dif2(a, n, tparams);
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mpd_free(tparams);
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return 1;
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}
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