127 lines
3.8 KiB
C
127 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) 2008, 2009 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 "fmpz.h"
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#include "fmpz_vec.h"
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#include "fmpz_poly.h"
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void
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_fmpz_poly_mullow(fmpz * res, const fmpz * poly1, slong len1,
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const fmpz * poly2, slong len2, slong n)
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{
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mp_size_t limbs1, limbs2;
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if (len2 < 7 || n < 7)
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{
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_fmpz_poly_mullow_classical(res, poly1, len1, poly2, len2, n);
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return;
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}
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limbs1 = _fmpz_vec_max_limbs(poly1, len1);
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limbs2 = _fmpz_vec_max_limbs(poly2, len2);
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if (n < 16 && (limbs1 > 12 || limbs2 > 12))
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{
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int clear = 0, i;
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fmpz *copy1, *copy2;
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if (len1 >= n)
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copy1 = (fmpz *) poly1;
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else
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{
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copy1 = (fmpz *) flint_malloc(n * sizeof(fmpz));
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for (i = 0; i < len1; i++)
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copy1[i] = poly1[i];
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flint_mpn_zero((mp_ptr) copy1 + len1, n - len1);
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clear |= 1;
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}
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if (len2 >= n)
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copy2 = (fmpz *) poly2;
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else
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{
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copy2 = (fmpz *) flint_malloc(n * sizeof(fmpz));
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for (i = 0; i < len2; i++)
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copy2[i] = poly2[i];
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flint_mpn_zero((mp_ptr) copy2 + len2, n - len2);
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clear |= 2;
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}
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_fmpz_poly_mullow_karatsuba_n(res, copy1, copy2, n);
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if (clear & 1)
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flint_free(copy1);
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if (clear & 2)
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flint_free(copy2);
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}
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else if (limbs1 + limbs2 <= 8)
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_fmpz_poly_mullow_KS(res, poly1, len1, poly2, len2, n);
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else if ((limbs1+limbs2)/2048 > len1 + len2)
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_fmpz_poly_mullow_KS(res, poly1, len1, poly2, len2, n);
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else if ((limbs1 + limbs2)*FLINT_BITS*4 < len1 + len2)
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_fmpz_poly_mullow_KS(res, poly1, len1, poly2, len2, n);
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else
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_fmpz_poly_mullow_SS(res, poly1, len1, poly2, len2, n);
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}
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void
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fmpz_poly_mullow(fmpz_poly_t res,
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const fmpz_poly_t poly1, const fmpz_poly_t poly2,
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slong n)
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{
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const slong len1 = poly1->length;
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const slong len2 = poly2->length;
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if (len1 == 0 || len2 == 0 || n == 0)
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{
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fmpz_poly_zero(res);
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return;
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}
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if (res == poly1 || res == poly2)
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{
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fmpz_poly_t t;
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fmpz_poly_init2(t, n);
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fmpz_poly_mullow(t, poly1, poly2, n);
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fmpz_poly_swap(res, t);
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fmpz_poly_clear(t);
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return;
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}
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n = FLINT_MIN(n, len1 + len2 - 1);
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fmpz_poly_fit_length(res, n);
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if (len1 >= len2)
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_fmpz_poly_mullow(res->coeffs, poly1->coeffs, len1, poly2->coeffs, len2, n);
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else
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_fmpz_poly_mullow(res->coeffs, poly2->coeffs, len2, poly1->coeffs, len1, n);
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_fmpz_poly_set_length(res, n);
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_fmpz_poly_normalise(res);
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}
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