/*=============================================================================

    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) 2009 Andy Novocin

******************************************************************************/

#include <gmp.h>
#include "flint.h"
#include "ulong_extras.h"
#include "fmpz.h"

extern double __gmpn_get_d(mp_limb_t *, size_t, size_t, slong);

double
fmpz_get_d_2exp(slong *exp, const fmpz_t f)
{
    fmpz d = *f;

    if (!COEFF_IS_MPZ(d))
    {
        ulong d_abs;
        if (d == WORD(0))
        {
            (*exp) = WORD(0);
            return 0.0;
        }
        d_abs = FLINT_ABS(d);
        (*exp) = FLINT_BIT_COUNT(d_abs);
        if (d < WORD(0))
            return __gmpn_get_d((mp_limb_t *) &d_abs, WORD(1), WORD(-1), -*exp);
        else
            return __gmpn_get_d((mp_limb_t *) &d, WORD(1), WORD(1), -*exp);
    }
    else
#if defined(__MPIR_VERSION)
       return mpz_get_d_2exp(exp, COEFF_TO_PTR(d));
#else
       return mpz_get_d_2exp((long *) exp, COEFF_TO_PTR(d));
#endif
}