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/* mpfr_get_z_exp -- get a multiple-precision integer from
a floating-point number
Copyright 2004, 2006 Free Software Foundation, Inc.
This file is part of the MPFR Library.
The MPFR Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or (at your
option) any later version.
The MPFR 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 Lesser General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with the MPFR Library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Place, Fifth Floor, Boston,
MA 02110-1301, USA. */
#include "mpfr-impl.h"
void
mpfr_get_z (mpz_ptr z, mpfr_srcptr f, mp_rnd_t rnd)
{
mpfr_t r;
mp_exp_t exp = MPFR_EXP (f);
/* if exp <= 0, then |f|<1, thus |o(f)|<=1 */
MPFR_ASSERTD (MPFR_PREC_MIN == 2);
mpfr_init2 (r, (exp <= 0) ? MPFR_PREC_MIN : exp + 1);
mpfr_rint (r, f, rnd);
MPFR_ASSERTN (MPFR_IS_FP (r) );
exp = mpfr_get_z_exp (z, r);
/* FIXME: It seems that exp < 0 is always true */
if (exp >= 0)
mpz_mul_2exp (z, z, exp);
else
mpz_div_2exp (z, z, -exp);
mpfr_clear (r);
}
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