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/* mpfr_set_q -- set a floating-point number from a multiple-precision rational
Copyright 2000, 2001, 2002, 2004 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., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA. */
#define MPFR_NEED_LONGLONG_H
#include "mpfr-impl.h"
/* set f to the rational q */
int
mpfr_set_q (mpfr_ptr f, mpq_srcptr q, mp_rnd_t rnd)
{
mpz_srcptr num, den;
mpfr_t n, d;
int inexact;
mp_prec_t prec;
MPFR_CLEAR_FLAGS (f);
num = mpq_numref (q);
if (mpz_cmp_ui (num, 0) == 0)
{
MPFR_SET_ZERO (f);
MPFR_SET_POS (f);
MPFR_RET (0);
}
den = mpq_denref (q);
mpfr_save_emin_emax ();
prec = mpz_sizeinbase (num, 2);
if (prec < MPFR_PREC_MIN)
prec = MPFR_PREC_MIN;
mpfr_init2 (n, prec);
if (mpfr_set_z (n, num, GMP_RNDZ)) /* result is exact unless overflow */
{
mpfr_clear (n);
mpfr_clear_flags ();
mpfr_restore_emin_emax ();
MPFR_SET_NAN (f);
MPFR_RET_NAN;
}
prec = mpz_sizeinbase(den, 2);
if (prec < MPFR_PREC_MIN)
prec = MPFR_PREC_MIN;
mpfr_init2 (d, prec);
if (mpfr_set_z (d, den, GMP_RNDZ)) /* result is exact unless overflow */
{
mpfr_clear (d);
mpfr_clear (n);
mpfr_clear_flags ();
mpfr_restore_emin_emax ();
MPFR_SET_NAN (f);
MPFR_RET_NAN;
}
inexact = mpfr_div (f, n, d, rnd);
mpfr_clear (n);
mpfr_clear (d);
mpfr_restore_emin_emax ();
return mpfr_check_range (f, inexact, rnd);
}
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