275 lines
8.7 KiB
C
275 lines
8.7 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 Mike Hansen
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******************************************************************************/
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#ifdef T
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#include "templates.h"
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void
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_TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (
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TEMPLATE(T, struct) * res,
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const TEMPLATE(T, struct) * poly,
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const fmpz_t e, ulong k,
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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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TEMPLATE(T, poly_struct) * precomp;
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TEMPLATE(T, poly_t) poly_squared;
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ulong twokm1;
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slong lenT, lenQ;
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slong i, l, j;
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int index;
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if (lenf == 2)
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{
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TEMPLATE(T, pow) (res, poly, e, ctx);
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return;
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}
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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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/* Precomputation */
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twokm1 = n_pow(2, k - 1);
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precomp = flint_malloc(twokm1 * sizeof(TEMPLATE(T, poly_struct)));
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TEMPLATE(T, poly_init) (precomp, ctx);
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TEMPLATE(T, poly_fit_length) (precomp, lenf - 1, ctx);
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_TEMPLATE(T, vec_set) (precomp->coeffs, poly, lenf - 1, ctx);
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TEMPLATE(T, poly_init) (poly_squared, ctx);
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if (k > 1)
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{
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TEMPLATE(T, poly_fit_length) (poly_squared, lenf - 1, ctx);
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_TEMPLATE(T, poly_mul) (T, poly, lenf - 1, poly, lenf - 1, ctx);
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_TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, poly_squared->coeffs, T,
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2 * lenf - 3, f, lenf, finv,
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lenfinv, ctx);
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}
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for (i = 1; i < twokm1; i++)
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{
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TEMPLATE(T, poly_init) (precomp + i, ctx);
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TEMPLATE(T, poly_fit_length) (precomp + i, lenf - 1, ctx);
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_TEMPLATE(T, poly_mul) (T, (precomp + i - 1)->coeffs, lenf - 1,
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poly_squared->coeffs, lenf - 1, ctx);
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_TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, (precomp + i)->coeffs, T,
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2 * lenf - 3, f, lenf, finv,
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lenfinv, ctx);
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}
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_TEMPLATE(T, vec_set) (res, poly, lenf - 1, ctx);
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i = fmpz_sizeinbase(e, 2) - 2;
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while (i >= 0)
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{
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if (fmpz_tstbit(e, i) == 0)
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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,
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f, lenf, finv, lenfinv,
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ctx);
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i -= 1;
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}
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else
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{
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l = FLINT_MAX(i - k + 1, 0);
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while (fmpz_tstbit(e, l) == 0)
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{
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l += 1;
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}
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for (j = 0; j < i - l + 1; j++)
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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,
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2 * lenf - 3, f,
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lenf, finv, lenfinv,
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ctx);
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}
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index = fmpz_tstbit(e, i);
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for (j = i - 1; j >= l; j--)
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{
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index = index << 1;
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index += fmpz_tstbit(e, j);
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}
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index = (index - 1) / 2;
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_TEMPLATE(T, poly_mul) (T, res, lenf - 1,
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(precomp + index)->coeffs, lenf - 1, ctx);
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_TEMPLATE(T, poly_divrem_newton_n_preinv) (Q, res, T, 2 * lenf - 3,
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f, lenf, finv, lenfinv,
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ctx);
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i = l - 1;
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}
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}
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for (j = 0; j < twokm1; j++)
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{
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TEMPLATE(T, poly_clear) (precomp + j, ctx);
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}
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flint_free(precomp);
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TEMPLATE(T, poly_clear) (poly_squared, ctx);
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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_fmpz_sliding_preinv) (TEMPLATE(T, poly_t) res,
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const TEMPLATE(T, poly_t) poly,
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const fmpz_t e, ulong k,
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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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TEMPLATE(T, struct) * q;
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slong len = poly->length;
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slong lenf = f->length;
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slong trunc = lenf - 1;
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int qcopy = 0;
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mp_bitcnt_t bits;
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if (lenf == 0)
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{
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TEMPLATE_PRINTF("Exception: %s_poly_powmod_fmpz_sliding_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_fmpz_sliding_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 (len >= lenf)
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{
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TEMPLATE(T, poly_t) t, r;
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TEMPLATE(T, poly_init) (t, ctx);
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TEMPLATE(T, poly_init) (r, ctx);
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TEMPLATE(T, poly_divrem) (t, r, poly, f, ctx);
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TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (res, r, e, k, f, finv,
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ctx);
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TEMPLATE(T, poly_clear) (t, ctx);
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TEMPLATE(T, poly_clear) (r, 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_set) (res, poly, ctx);
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}
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else
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TEMPLATE(T, poly_mulmod_preinv) (res, poly, poly, f, finv,
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ctx);
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return;
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}
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}
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if (lenf == 1 || len == 0)
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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 (poly->length < trunc)
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{
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q = _TEMPLATE(T, vec_init) (trunc, ctx);
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_TEMPLATE(T, vec_set) (q, poly->coeffs, len, ctx);
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_TEMPLATE(T, vec_zero) (q + len, trunc - len, ctx);
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qcopy = 1;
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}
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else
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{
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q = poly->coeffs;
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}
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/* Determine "optimum" sliding window size */
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if (k == 0)
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{
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bits = fmpz_bits(e);
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if (bits < 9)
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k = 1;
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else if (bits < 15)
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k = 2;
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else if (bits < 62)
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k = 3;
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else if (bits < 203)
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k = 4;
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else if (bits < 587)
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k = 5;
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else if (bits < 1560)
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k = 6;
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else
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k = 7;
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}
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if ((res == poly && !qcopy) || (res == f))
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{
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TEMPLATE(T, poly_t) t;
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TEMPLATE(T, poly_init2) (t, 2 * lenf - 3, ctx);
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_TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (t->coeffs, q, e, k,
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f->coeffs, lenf,
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finv->coeffs,
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finv->length, ctx);
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TEMPLATE(T, poly_swap) (res, t, ctx);
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TEMPLATE(T, poly_clear) (t, ctx);
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}
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else
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{
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TEMPLATE(T, poly_fit_length) (res, 2 * lenf - 3, ctx);
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_TEMPLATE(T, poly_powmod_fmpz_sliding_preinv) (res->coeffs, q, e, k,
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f->coeffs, lenf,
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finv->coeffs,
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finv->length, ctx);
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}
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if (qcopy)
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_TEMPLATE(T, vec_clear) (q, trunc, ctx);
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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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