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/* double mpf_get_d (mpf_t src) -- Return the double approximation to SRC.
Copyright (C) 1996 Free Software Foundation, Inc.
This file is part of the GNU MP Library.
The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published by
the Free Software Foundation; either version 2 of the License, or (at your
option) any later version.
The GNU MP Library 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 Library General Public
License for more details.
You should have received a copy of the GNU Library General Public License
along with the GNU MP Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#include "gmp.h"
#include "gmp-impl.h"
double
#if __STDC__
mpf_get_d (mpf_srcptr src)
#else
mpf_get_d (src)
mpf_srcptr src;
#endif
{
double res;
mp_size_t size, i, n_limbs_to_use;
int negative;
mp_ptr qp;
size = SIZ(src);
if (size == 0)
return 0.0;
negative = size < 0;
size = ABS (size);
qp = PTR(src);
res = qp[size - 1];
n_limbs_to_use = MIN (LIMBS_PER_DOUBLE, size);
for (i = 2; i <= n_limbs_to_use; i++)
res = res * MP_BASE_AS_DOUBLE + qp[size - i];
res = __gmp_scale2 (res, (EXP(src) - n_limbs_to_use) * BITS_PER_MP_LIMB);
return negative ? -res : res;
}
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