Java Bit Count bitSizeForSignedValue(final int value)

Description

bit Size For Signed Value

License

Open Source License

Return

The number of bits required to store the specified value as a signed integer, i.e. a result in [1,32].

Declaration

public static int bitSizeForSignedValue(final int value) 

Method Source Code

//package com.java2s;
//License from project: Open Source License 

public class Main {
    /**//  w  w w .ja va 2 s  . c o m
     * @return The number of bits required to store the specified value as a signed integer, i.e. a result in [1,32].
     */
    public static int bitSizeForSignedValue(final int value) {
        if (value > 0) {
            return 33 - Integer.numberOfLeadingZeros(value);
        } else if (value == 0) {
            return 1;
        } else {
            // Works for Integer.MIN_VALUE as well.
            return 33 - Integer.numberOfLeadingZeros(-value - 1);
        }
    }

    /**
     * @return The number of bits required to store the specified value as a signed integer, i.e. a result in [1,64].
     */
    public static int bitSizeForSignedValue(final long value) {
        if (value > 0) {
            return 65 - Long.numberOfLeadingZeros(value);
        } else if (value == 0) {
            return 1;
        } else {
            // Works for Long.MIN_VALUE as well.
            return 65 - Long.numberOfLeadingZeros(-value - 1);
        }
    }
}

Related

1. bitCountSlow(int x)
2. bitLength(byte[] bytes)
3. bitLength(final int byteLength)
4. bitLength(int num)
5. bitLength(int value)
6. bitSizeForUnsignedValue(final int value)
7. countBits (long v)
8. countBits(byte num)
9. countBits(final int intValue)