/* mpfr_set_q -- set a floating-point number from a multiple-precision rational

Copyright (C) 2000 PolKA project, Inria Lorraine and Loria

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 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 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 Library General Public
License for more details.

You should have received a copy of the GNU Library 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. */

#include "gmp.h"
#include "gmp-impl.h"
#include "longlong.h"
#include "mpfr.h"

/* set f to the rational q */
void
#if __STDC__
mpfr_set_q (mpfr_ptr f, mpq_srcptr q, mp_rnd_t rnd)
#else
mpfr_set_q (f, q, rnd) 
     mpfr_ptr f;
     mpq_srcptr q;
     mp_rnd_t rnd;
#endif
{
  int sign;
  mpz_srcptr num, den;
  unsigned int prec;
  mpfr_t n,d;

  num = mpq_numref(q);
  sign = mpz_cmp_ui(num, 0);
  if (sign==0) {
    SET_ZERO(f);
    return;
  }

  den = mpq_denref(q);
  prec = PREC(f);
  mpfr_init2(n, mpz_sizeinbase(num, 2));
  mpfr_set_z(n, num, GMP_RNDZ); /* result is exact */
  mpfr_init2(d, mpz_sizeinbase(den, 2));
  mpfr_set_z(d, den, GMP_RNDZ); /* result is exact */
  PREC(f) = prec; 
  mpfr_div(f, n, d, rnd);
  mpfr_clear(n); mpfr_clear(d);
}