/* mpc_ceil_log2 - returns ceil(log(d)/log(2))

Copyright (C) INRIA, 2004, 2009, 2010

This file is part of the MPC Library.

The MPC 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 MPC 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 MPC 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 "mpc-impl.h"

/* returns ceil(log(d)/log(2)) if d > 0 */

/* Don't use count_leading_zeros since it is in longlong.h */

mpfr_prec_t

mpc_ceil_log2 (mpfr_prec_t d)

{

  mpfr_prec_t exp;

  for (exp = 0; d > 1; d = (d + 1) / 2)

    exp++;

  return exp;

}