74 lines
2.0 KiB
C
74 lines
2.0 KiB
C
|
/*=============================================================================
|
||
|
|
|
||
|
|
This file is part of FLINT.
|
||
|
|
|
||
|
|
FLINT is free software; you can redistribute it and/or modify
|
||
|
|
it under the terms of the GNU General Public License as published by
|
||
|
|
the Free Software Foundation; either version 2 of the License, or
|
||
|
|
(at your option) any later version.
|
||
|
|
|
||
|
|
FLINT is distributed in the hope that it will be useful,
|
||
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
|
|
GNU General Public License for more details.
|
||
|
|
|
||
|
|
You should have received a copy of the GNU General Public License
|
||
|
|
along with FLINT; if not, write to the Free Software
|
||
|
|
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
||
|
|
|
||
|
|
=============================================================================*/
|
||
|
|
/******************************************************************************
|
||
|
|
|
||
|
|
Copyright (C) 2011 Fredrik Johansson
|
||
|
|
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <gmp.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "fmpz.h"
|
||
|
|
#include "ulong_extras.h"
|
||
|
|
|
||
|
|
void
|
||
|
|
fmpz_randtest_mod(fmpz_t f, flint_rand_t state, const fmpz_t m)
|
||
|
|
{
|
||
|
|
fmpz_t t;
|
||
|
|
|
||
|
|
fmpz_init(t);
|
||
|
|
fmpz_randtest_unsigned(t, state, fmpz_bits(m) + 2);
|
||
|
|
fmpz_mod(t, t, m);
|
||
|
|
|
||
|
|
if (n_randlimb(state) & UWORD(1))
|
||
|
|
{
|
||
|
|
fmpz_sub(t, m, t);
|
||
|
|
fmpz_sub_ui(t, t, UWORD(1));
|
||
|
|
}
|
||
|
|
|
||
|
|
fmpz_set(f, t);
|
||
|
|
fmpz_clear(t);
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
fmpz_randtest_mod_signed(fmpz_t f, flint_rand_t state, const fmpz_t m)
|
||
|
|
{
|
||
|
|
/* Randomly generate m/2 when included in the range */
|
||
|
|
if ((n_randlimb(state) % 32 == 1) && (fmpz_fdiv_ui(m, 2) == 0))
|
||
|
|
{
|
||
|
|
fmpz_fdiv_q_ui(f, m, UWORD(2));
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
fmpz_t t;
|
||
|
|
fmpz_init(t);
|
||
|
|
fmpz_tdiv_q_ui(t, m, UWORD(2));
|
||
|
|
fmpz_randtest_mod(t, state, t);
|
||
|
|
if (n_randlimb(state) & UWORD(1))
|
||
|
|
{
|
||
|
|
fmpz_neg(t, t);
|
||
|
|
}
|
||
|
|
fmpz_set(f, t);
|
||
|
|
fmpz_clear(t);
|
||
|
|
}
|
||
|
|
}
|