61 lines
1.9 KiB
C
61 lines
1.9 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) 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
|
|
}
|