Java Ceil ceilPoT(int arg)

Description

Computes closest power of two that is not less than argument.

License

Open Source License

Parameter

Parameter	Description
arg	Greather than zero and not greather than 2^31.

Return

Closest power of two not less than argument, or argument itself.

Declaration

public static int ceilPoT(int arg) 

Method Source Code

//package com.java2s;
/*// w w  w  . ja  v a  2s.  c o  m
 * The MIT License
 *
 * Copyright 2014 Piotr SQLek Sk?lski.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

public class Main {
    /** Computes closest power of two that is not less than argument.
     *
     * @param arg Greather than zero and not greather than 2^31.
     * @return Closest power of two not less than argument, or argument itself.
     */
    public static int ceilPoT(int arg) {
        if (arg < 1)
            throw new IllegalArgumentException("Argument of ceilPoT must be two or greater.");
        if (arg > 0x40000000)
            throw new IllegalArgumentException("Argument of ceilPoT greater than 2^31.");
        --arg;
        arg |= arg >> 1;
        arg |= arg >> 2;
        arg |= arg >> 4;
        arg |= arg >> 8;
        arg |= arg >> 16;
        return ++arg;
    }
}

Related

1. ceilInt(final double x)
2. ceilLogBaseTwo(final int i)
3. ceilMaskPOT(int n)
4. ceilMultiple(float source, float multiple)
5. ceilPositive(float x)
6. ceilPow2(int v)
7. ceilPowerOf2(final long x)
8. ceilPowerOf2(int x)
9. ceilPowerOf2Bits(final long x)