74 lines
2.0 KiB
C
74 lines
2.0 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) 2011 Fredrik Johansson
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******************************************************************************/
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#include <stdio.h>
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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 "ulong_extras.h"
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void
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fmpz_randtest_mod(fmpz_t f, flint_rand_t state, const fmpz_t m)
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{
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fmpz_t t;
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fmpz_init(t);
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fmpz_randtest_unsigned(t, state, fmpz_bits(m) + 2);
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fmpz_mod(t, t, m);
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if (n_randlimb(state) & UWORD(1))
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{
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fmpz_sub(t, m, t);
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fmpz_sub_ui(t, t, UWORD(1));
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}
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fmpz_set(f, t);
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fmpz_clear(t);
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}
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void
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fmpz_randtest_mod_signed(fmpz_t f, flint_rand_t state, const fmpz_t m)
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{
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/* Randomly generate m/2 when included in the range */
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if ((n_randlimb(state) % 32 == 1) && (fmpz_fdiv_ui(m, 2) == 0))
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{
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fmpz_fdiv_q_ui(f, m, UWORD(2));
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}
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else
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{
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fmpz_t t;
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fmpz_init(t);
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fmpz_tdiv_q_ui(t, m, UWORD(2));
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fmpz_randtest_mod(t, state, t);
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if (n_randlimb(state) & UWORD(1))
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{
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fmpz_neg(t, t);
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}
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fmpz_set(f, t);
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fmpz_clear(t);
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}
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}
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