Perform Vector Calculations Fast Using Java’s new Vector API (Incubator Mode)

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Let us say you want to add the elements of two arrays which are of equal size.

The first element of array 1 should be added to the first element of array 2,

The second element of array 1 to the second element of array 2 and so on until you reach the end of the arrays.

How do you do this in Java?

Using a code like this :

public class ScalarExample {
    public static void main(String[] args) {
        int[] arr1 = {1, 2, 3, 4, 5};
        int[] arr2 = {6, 7, 8, 9, 10};
        int[] result = new int[5];

        for (int i = 0; i < arr1.length; i++) {
            result[i] = arr1[i] + arr2[i];
        }

        // Print result
        for (int value : result) {
            System.out.print(value + " ");
        }
    }
}

Pretty straightforward!

There is something to note here which is very obvious. You perform one addition at a time. So, in the above case since the array size is 5 you perform 5 operations sequentially through 5 CPU instructions.

This is called a scalar operation.

What if you could do this addition in a single CPU instruction and the 5 elements are added at the same time?