pqc/external/flint-2.4.3/fmpq/get_mpfr.c
2014-05-24 23:16:06 +02:00

63 lines
1.8 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 "fmpq.h"
int
fmpq_get_mpfr(mpfr_t r, const fmpq_t x, mpfr_rnd_t rnd)
{
__mpq_struct mpq;
fmpz p, q;
mp_limb_t pp, qq;
p = *fmpq_numref(x);
q = *fmpq_denref(x);
if (p == 0)
return mpfr_set_ui(r, 0, rnd);
if (COEFF_IS_MPZ(p))
mpq._mp_num = *COEFF_TO_PTR(p);
else
{
pp = FLINT_ABS(p);
mpq._mp_num._mp_alloc = 1;
mpq._mp_num._mp_size = (p < 0) ? -1 : 1;
mpq._mp_num._mp_d = &pp;
}
if (COEFF_IS_MPZ(q))
mpq._mp_den = *COEFF_TO_PTR(q);
else
{
qq = q;
mpq._mp_den._mp_alloc = 1;
mpq._mp_den._mp_size = 1;
mpq._mp_den._mp_d = &qq;
}
return mpfr_set_q(r, &mpq, rnd);
}