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

Copyright 2004, 2009 Patrick Pelissier, Paul Zimmermann, Philippe Th\'eveny

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 */
unsigned long
mpc_ceil_log2 (unsigned long d)
{
  unsigned long exp;

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