101 lines
2.6 KiB
C
101 lines
2.6 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) 2009 William Hart
|
||
|
|
Copyright (C) 2011 Fredrik Johansson
|
||
|
|
|
||
|
|
******************************************************************************/
|
||
|
|
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <gmp.h>
|
||
|
|
#include "flint.h"
|
||
|
|
#include "ulong_extras.h"
|
||
|
|
#include "fmpz.h"
|
||
|
|
|
||
|
|
void
|
||
|
|
_fmpz_CRT_ui_precomp(fmpz_t out, const fmpz_t r1, const fmpz_t m1, ulong r2,
|
||
|
|
ulong m2, mp_limb_t m2inv, const fmpz_t m1m2, mp_limb_t c, int sign)
|
||
|
|
{
|
||
|
|
mp_limb_t r1mod, s;
|
||
|
|
fmpz_t r1normal;
|
||
|
|
fmpz_t tmp;
|
||
|
|
|
||
|
|
fmpz_init(tmp);
|
||
|
|
|
||
|
|
/* FIXME: assume r1 moved to [0, m1); add tests for this */
|
||
|
|
if (fmpz_sgn(r1) < 0)
|
||
|
|
{
|
||
|
|
fmpz_init(r1normal);
|
||
|
|
fmpz_add(r1normal, r1, m1);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
*r1normal = *r1;
|
||
|
|
}
|
||
|
|
|
||
|
|
r1mod = fmpz_fdiv_ui(r1normal, m2);
|
||
|
|
s = n_submod(r2, r1mod, m2);
|
||
|
|
s = n_mulmod2_preinv(s, c, m2, m2inv);
|
||
|
|
fmpz_mul_ui(tmp, m1, s);
|
||
|
|
fmpz_add(tmp, tmp, r1normal);
|
||
|
|
|
||
|
|
if (fmpz_sgn(r1) < 0)
|
||
|
|
fmpz_clear(r1normal);
|
||
|
|
|
||
|
|
if (sign)
|
||
|
|
{
|
||
|
|
fmpz_sub(out, tmp, m1m2);
|
||
|
|
if (fmpz_cmpabs(tmp, out) <= 0)
|
||
|
|
fmpz_set(out, tmp);
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
fmpz_set(out, tmp);
|
||
|
|
}
|
||
|
|
|
||
|
|
fmpz_clear(tmp);
|
||
|
|
}
|
||
|
|
|
||
|
|
void fmpz_CRT_ui(fmpz_t out, const fmpz_t r1, const fmpz_t m1,
|
||
|
|
ulong r2, ulong m2, int sign)
|
||
|
|
{
|
||
|
|
mp_limb_t c;
|
||
|
|
fmpz_t m1m2;
|
||
|
|
|
||
|
|
c = fmpz_fdiv_ui(m1, m2);
|
||
|
|
c = n_invmod(c, m2);
|
||
|
|
|
||
|
|
if (c == 0)
|
||
|
|
{
|
||
|
|
flint_printf("Exception (fmpz_CRT_ui). m1 not invertible modulo m2.\n");
|
||
|
|
abort();
|
||
|
|
}
|
||
|
|
|
||
|
|
fmpz_init(m1m2);
|
||
|
|
fmpz_mul_ui(m1m2, m1, m2);
|
||
|
|
|
||
|
|
_fmpz_CRT_ui_precomp(out, r1, m1, r2, m2, n_preinvert_limb(m2),
|
||
|
|
m1m2, c, sign);
|
||
|
|
|
||
|
|
fmpz_clear(m1m2);
|
||
|
|
}
|