beetle-pce-fast-libretro/mednafen/math_ops.cpp
2012-06-03 17:48:14 +02:00

37 lines
1.0 KiB
C++

/* Mednafen - Multi-system Emulator
*
* 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
*/
#include "mednafen.h"
#include "math_ops.h"
// Source: http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
// Rounds up to the nearest power of 2.
uint32 round_up_pow2(uint32 v)
{
v--;
v |= v >> 1;
v |= v >> 2;
v |= v >> 4;
v |= v >> 8;
v |= v >> 16;
v++;
v += (v == 0);
return(v);
}