mariadb/mysys/my_bit.c

/* Copyright (C) 2000 MySQL AB

   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 2 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, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

/* Some useful bit functions */

#include "mysys_priv.h"

/*
  Find smallest X in 2^X >= value
  This can be used to divide a number with value by doing a shift instead
*/

uint my_bit_log2(ulong value)
{
  uint bit;
  for (bit=0 ; value > 1 ; value>>=1, bit++) ;
  return bit;
}