87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
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/*=============================================================================
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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) 2011 Fredrik Johansson
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******************************************************************************/
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#include <stdlib.h>
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#include "flint.h"
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#include "fmpz_poly.h"
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#include "fmpz_poly_mat.h"
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#define E fmpz_poly_mat_entry
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static __inline__ void
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fmpz_poly_addlow(fmpz_poly_t c, const fmpz_poly_t a,
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const fmpz_poly_t b, slong len)
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{
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fmpz_poly_add(c, a, b);
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fmpz_poly_truncate(c, len);
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}
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void
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fmpz_poly_mat_sqrlow(fmpz_poly_mat_t B, const fmpz_poly_mat_t A, slong len)
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{
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slong n = A->r;
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if (n == 0)
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return;
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if (len < 1)
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{
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fmpz_poly_mat_zero(B);
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return;
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}
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if (n == 1)
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{
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fmpz_poly_sqrlow(E(B, 0, 0), E(A, 0, 0), len);
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return;
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}
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if (n == 2)
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{
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fmpz_poly_t t, u;
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fmpz_poly_init(t);
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fmpz_poly_init(u);
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fmpz_poly_addlow(t, E(A, 0, 0), E(A, 1, 1), len);
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fmpz_poly_mullow(u, E(A, 0, 1), E(A, 1, 0), len);
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fmpz_poly_sqrlow(E(B, 0, 0), E(A, 0, 0), len);
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fmpz_poly_addlow(E(B, 0, 0), E(B, 0, 0), u, len);
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fmpz_poly_sqrlow(E(B, 1, 1), E(A, 1, 1), len);
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fmpz_poly_addlow(E(B, 1, 1), E(B, 1, 1), u, len);
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fmpz_poly_mullow(E(B, 0, 1), E(A, 0, 1), t, len);
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fmpz_poly_mullow(E(B, 1, 0), E(A, 1, 0), t, len);
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fmpz_poly_clear(t);
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fmpz_poly_clear(u);
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return;
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}
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fmpz_poly_mat_mullow(B, A, A, len);
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}
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