Java Number Round roundUpPow2(int x)

Description

Rounds an integer up to the next power of 2.

License

Open Source License

Parameter

Parameter	Description
x	a parameter

Return

the lowest power of 2 greater or equal to x

Declaration

public static int roundUpPow2(int x) 

Method Source Code

//package com.java2s;
/*/*from  w  w  w  . j  a  v  a  2  s .c o  m*/
 * Copyright (C) 2012 CyborgDev <cyborg@alta189.com>
 *
 * This file is part of Cyborg
 *
 * Cyborg 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.
 *
 * Cyborg 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.  If not, see <http://www.gnu.org/licenses/>.
 */

public class Main {
    /**
     * Rounds an integer up to the next power of 2.
     * @param x
     * @return the lowest power of 2 greater or equal to x
     */
    public static int roundUpPow2(int x) {
        if (x <= 0) {
            return 1;
        } else if (x > 0x40000000) {
            throw new IllegalArgumentException(
                    "Rounding " + x + " to the next highest power of two would exceed the int range");
        } else {
            x--;
            x |= x >> 1;
            x |= x >> 2;
            x |= x >> 4;
            x |= x >> 8;
            x |= x >> 16;
            x++;
            return x;
        }
    }
}

Related

1. roundUpIfNecessary(long timeout, long convertedTimeout)
2. roundUpLong(long value, long interval)
3. roundUpLong(long x, long blockSizePowerOf2)
4. roundUpNumberByUsingMultipleValue(double number, double multiple)
5. roundUpPOT(int value)
6. roundUpPower2(int i)
7. roundUpPower2(int v)
8. roundUpTo(double in, double del)
9. roundUpTo(int a, int quanta)