121 lines
3.8 KiB
C
121 lines
3.8 KiB
C
/*=============================================================================
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This file is part of FLINT.
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FLINT is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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FLINT is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with FLINT; if not, write to the Free Software
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Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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=============================================================================*/
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/******************************************************************************
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Copyright (C) 2010 William Hart
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Copyright (C) 2010 Sebastian Pancratz
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******************************************************************************/
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#include <stdlib.h>
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#include <gmp.h>
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#include "flint.h"
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#include "nmod_vec.h"
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#include "nmod_poly.h"
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void
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_nmod_poly_mullow_KS(mp_ptr out, mp_srcptr in1, slong len1,
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mp_srcptr in2, slong len2, mp_bitcnt_t bits, slong n, nmod_t mod)
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{
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slong limbs1, limbs2;
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mp_ptr mpn1, mpn2, res;
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if (bits == 0)
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{
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mp_bitcnt_t bits1, bits2, loglen;
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bits1 = _nmod_vec_max_bits(in1, len1);
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bits2 = (in1 == in2) ? bits1 : _nmod_vec_max_bits(in2, len2);
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loglen = FLINT_BIT_COUNT(len2);
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bits = bits1 + bits2 + loglen;
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}
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limbs1 = (len1 * bits - 1) / FLINT_BITS + 1;
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limbs2 = (len2 * bits - 1) / FLINT_BITS + 1;
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mpn1 = (mp_ptr) flint_malloc(sizeof(mp_limb_t) * limbs1);
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mpn2 = (in1 == in2) ? mpn1 : (mp_ptr) flint_malloc(sizeof(mp_limb_t) * limbs2);
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_nmod_poly_bit_pack(mpn1, in1, len1, bits);
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if (in1 != in2)
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_nmod_poly_bit_pack(mpn2, in2, len2, bits);
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res = (mp_ptr) flint_malloc(sizeof(mp_limb_t) * (limbs1 + limbs2));
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mpn_mul(res, mpn1, limbs1, mpn2, limbs2);
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_nmod_poly_bit_unpack(out, n, res, bits, mod);
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flint_free(mpn2);
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if (in1 != in2)
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flint_free(mpn1);
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flint_free(res);
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}
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void
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nmod_poly_mullow_KS(nmod_poly_t res,
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const nmod_poly_t poly1, const nmod_poly_t poly2,
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mp_bitcnt_t bits, slong n)
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{
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slong len_out;
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if ((poly1->length == 0) || (poly2->length == 0))
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{
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nmod_poly_zero(res);
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return;
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}
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len_out = poly1->length + poly2->length - 1;
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if (n > len_out)
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n = len_out;
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if (res == poly1 || res == poly2)
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{
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nmod_poly_t temp;
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nmod_poly_init2_preinv(temp, poly1->mod.n, poly1->mod.ninv, len_out);
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if (poly1->length >= poly2->length)
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_nmod_poly_mullow_KS(temp->coeffs, poly1->coeffs, poly1->length,
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poly2->coeffs, poly2->length, bits,
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n, poly1->mod);
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else
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_nmod_poly_mullow_KS(temp->coeffs, poly2->coeffs, poly2->length,
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poly1->coeffs, poly1->length, bits,
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n, poly1->mod);
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nmod_poly_swap(res, temp);
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nmod_poly_clear(temp);
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}
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else
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{
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nmod_poly_fit_length(res, len_out);
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if (poly1->length >= poly2->length)
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_nmod_poly_mullow_KS(res->coeffs, poly1->coeffs, poly1->length,
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poly2->coeffs, poly2->length, bits,
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n, poly1->mod);
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else
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_nmod_poly_mullow_KS(res->coeffs, poly2->coeffs, poly2->length,
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poly1->coeffs, poly1->length, bits,
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n, poly1->mod);
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}
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res->length = n;
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_nmod_poly_normalise(res);
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}
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