99 lines
2.5 KiB
C
99 lines
2.5 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, 2012 Sebastian Pancratz
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Copyright (C) 2012 Fredrik Johansson
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******************************************************************************/
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#include "padic.h"
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slong _padic_exp_bound(slong v, slong N, const fmpz_t p)
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{
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if (fmpz_fits_si(p))
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{
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fmpz_t n, d, f;
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slong i;
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fmpz_init(n);
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fmpz_init(d);
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fmpz_init(f);
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fmpz_sub_ui(f, p, 1);
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fmpz_mul_ui(n, f, N);
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fmpz_sub_ui(n, n, 1);
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fmpz_mul_ui(d, f, v);
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fmpz_sub_ui(d, d, 1);
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fmpz_cdiv_q(f, n, d);
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i = fmpz_get_si(f);
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fmpz_clear(n);
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fmpz_clear(d);
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fmpz_clear(f);
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return i;
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}
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else
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{
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return (N + (v - 1)) / v;
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}
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}
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void _padic_exp(fmpz_t rop, const fmpz_t u, slong v, const fmpz_t p, slong N)
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{
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if (N < 1024)
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_padic_exp_rectangular(rop, u, v, p, N);
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else
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_padic_exp_balanced(rop, u, v, p, N);
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}
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int padic_exp(padic_t rop, const padic_t op, const padic_ctx_t ctx)
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{
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const slong N = padic_prec(rop);
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const slong v = padic_val(op);
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const fmpz *p = ctx->p;
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if (padic_is_zero(op))
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{
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padic_one(rop);
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return 1;
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}
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if ((fmpz_equal_ui(p, 2) && v <= 1) || (v <= 0))
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{
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return 0;
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}
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else
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{
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if (v < N)
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{
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_padic_exp(padic_unit(rop), padic_unit(op), padic_val(op), p, N);
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padic_val(rop) = 0;
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}
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else
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{
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padic_one(rop);
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}
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return 1;
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}
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}
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