213 lines
6.4 KiB
C
213 lines
6.4 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) 2013 Martin Lee
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Copyright (C) 2013 Mike Hansen
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******************************************************************************/
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#ifdef T
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#include "templates.h"
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#include "long_extras.h"
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void
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_TEMPLATE(T, poly_powmod_x_fmpz_preinv) (
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TEMPLATE(T, struct) * res,
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const fmpz_t e,
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const TEMPLATE(T, struct) * f, slong lenf,
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const TEMPLATE(T, struct) * finv, slong lenfinv,
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const TEMPLATE(T, ctx_t) ctx)
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{
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TEMPLATE(T, struct) * T, *Q;
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slong lenT, lenQ;
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slong i, window, l, c;
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lenT = 2 * lenf - 3;
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lenQ = lenT - lenf + 1;
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T = _TEMPLATE(T, vec_init) (lenT + lenQ, ctx);
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Q = T + lenT;
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TEMPLATE(T, one) (res, ctx);
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l = z_sizeinbase(lenf - 1, 2) - 2;
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window = 0;
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window = (1 << l);
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c = l;
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i = fmpz_sizeinbase(e, 2) - 2;
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if (i <= l)
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{
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window = 0;
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window = (1 << i);
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c = i;
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l = i;
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}
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if (c == 0)
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{
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_TEMPLATE(T, poly_shift_left) (T, res, lenf - 1, window, ctx);
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_TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T,
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lenf - 1 + window, f, lenf,
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finv, lenfinv, ctx);
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c = l + 1;
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window = 0;
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}
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for (; i >= 0; i--)
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{
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_TEMPLATE(T, poly_sqr) (T, res, lenf - 1, ctx);
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_TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T, 2 * lenf - 3, f,
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lenf, finv, lenfinv, ctx);
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c--;
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if (fmpz_tstbit(e, i))
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{
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if (window == 0 && i <= l - 1)
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c = i;
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if (c >= 0)
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window = window | (1 << c);
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}
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else if (window == 0)
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{
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c = l + 1;
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}
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if (c == 0)
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{
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_TEMPLATE(T, poly_shift_left) (T, res, lenf - 1, window, ctx);
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_TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T,
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lenf - 1 + window, f,
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lenf, finv, lenfinv,
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ctx);
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c = l + 1;
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window = 0;
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}
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}
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_TEMPLATE(T, vec_clear) (T, lenT + lenQ, ctx);
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}
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void
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TEMPLATE(T, poly_powmod_x_fmpz_preinv) (TEMPLATE(T, poly_t) res,
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const fmpz_t e,
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const TEMPLATE(T, poly_t) f,
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const TEMPLATE(T, poly_t) finv,
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const TEMPLATE(T, ctx_t) ctx)
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{
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slong lenf = f->length;
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slong trunc = lenf - 1;
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TEMPLATE(T, poly_t) tmp;
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if (lenf == 0)
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{
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TEMPLATE_PRINTF("Exception: %s_poly_powmod_x_preinv:", T);
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flint_printf(" divide by zero\n");
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abort();
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}
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if (fmpz_sgn(e) < 0)
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{
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TEMPLATE_PRINTF("Exception: %s_poly_powmod_x_preinv: ", T);
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flint_printf(" negative exp not implemented\n");
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abort();
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}
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if (lenf == 1)
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{
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TEMPLATE(T, poly_zero) (res, ctx);
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return;
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}
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if (lenf == 2)
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{
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TEMPLATE(T, poly_t) r, poly;
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TEMPLATE(T, poly_init) (tmp, ctx);
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TEMPLATE(T, poly_init) (r, ctx);
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TEMPLATE(T, poly_init2) (poly, 2, ctx);
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TEMPLATE(T, poly_gen) (poly, ctx);
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TEMPLATE(T, poly_divrem) (tmp, r, poly, f, ctx);
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TEMPLATE(T, poly_powmod_fmpz_binexp_preinv) (res, r, e, f, finv, ctx);
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TEMPLATE(T, poly_clear) (tmp, ctx);
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TEMPLATE(T, poly_clear) (r, ctx);
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TEMPLATE(T, poly_clear) (poly, ctx);
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return;
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}
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if (fmpz_abs_fits_ui(e))
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{
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ulong exp = fmpz_get_ui(e);
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if (exp <= 2)
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{
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if (exp == UWORD(0))
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{
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TEMPLATE(T, poly_fit_length) (res, 1, ctx);
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TEMPLATE(T, one) (res->coeffs, ctx);
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_TEMPLATE(T, poly_set_length) (res, 1, ctx);
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}
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else if (exp == UWORD(1))
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{
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TEMPLATE(T, poly_t) r;
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TEMPLATE(T, poly_init2) (r, 2, ctx);
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TEMPLATE(T, poly_gen) (r, ctx);
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TEMPLATE(T, poly_init) (tmp, ctx);
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TEMPLATE(T, poly_divrem) (tmp, res, r, f, ctx);
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TEMPLATE(T, poly_clear) (tmp, ctx);
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TEMPLATE(T, poly_clear) (r, ctx);
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}
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else
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{
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TEMPLATE(T, poly_init2) (tmp, 3, ctx);
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TEMPLATE(T, poly_gen) (tmp, ctx);
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TEMPLATE(T, poly_mulmod) (res, tmp, tmp, f, ctx);
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TEMPLATE(T, poly_clear) (tmp, ctx);
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}
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return;
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}
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}
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if ((res == f) || (res == finv))
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{
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TEMPLATE(T, poly_init2) (tmp, trunc, ctx);
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_TEMPLATE(T, poly_powmod_x_fmpz_preinv) (tmp->coeffs, e, f->coeffs,
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lenf, finv->coeffs,
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finv->length, ctx);
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TEMPLATE(T, poly_swap) (res, tmp, ctx);
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TEMPLATE(T, poly_clear) (tmp, ctx);
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}
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else
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{
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TEMPLATE(T, poly_fit_length) (res, trunc, ctx);
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_TEMPLATE(T, poly_powmod_x_fmpz_preinv) (res->coeffs, e, f->coeffs,
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lenf, finv->coeffs,
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finv->length, ctx);
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}
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_TEMPLATE(T, poly_set_length) (res, trunc, ctx);
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_TEMPLATE(T, poly_normalise) (res, ctx);
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}
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#endif
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