Subversion Repositories openrisc_2011-10-31

/* misc.c -- Misc. routines that just don't fit anywhere else

   Copyright (C) 1999 Damjan Lampret, lampret@opencores.org

   Copyright (C) 2002 Marko Mlinar, markom@opencores.org

   Copyright (C) 2008 Embecosm Limited

   Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>

   This file is part of Or1ksim, the OpenRISC 1000 Architectural Simulator.

   This program is free software; you can redistribute it and/or modify it

   under the terms of the GNU General Public License as published by the Free

   Software Foundation; either version 3 of the License, or (at your option)

   any later version.

   This program 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 General Public License for

   more details.

   You should have received a copy of the GNU General Public License along

   with this program.  If not, see <http://www.gnu.org/licenses/>.  */

/* This program is commented throughout in a fashion suitable for processing

   with Doxygen. */

/* Autoconf and/or portability configuration */

#include "config.h"

/* returns log2(x) */

/* Call this log2_int, because there is a library function named log2 */

int

log2_int (unsigned long x)

{

  int c = 0;

  if (!x)

    return 0;                    /* not by the book, but practical */

  while (x != 1)

    x >>= 1, c++;

  return c;

}

int

is_power2 (int x)

{

  if (!x)

    return 0;

  while (!(x & 1))

    x >>= 1;

  return x == 1;

}