mysys/my_bit.c


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/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
   
   This 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.
   
   This 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 this library; 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;
}