Java 18: Vector API

Vector API is a new feature introduced in Java 18 that provides a set of vectorized operations that can be used to accelerate mathematical computations. Vector API enables developers to write code that can take advantage of the latest hardware, including CPUs with vector units and GPUs.

Vector API provides a set of classes and interfaces that can be used to write code that performs vectorized operations on arrays of numeric data. The API supports operations such as addition, multiplication, and division, as well as more complex operations such as dot products, norms, and reductions. The API also includes support for complex numbers and floating-point operations.

Here's an example of how Vector API can be used to accelerate a simple mathematical operation:

import jdk.incubator.vector.*;

public class VectorExample {

    public static void main(String[] args) {

        float[] a = {1.0f, 2.0f, 3.0f, 4.0f};

        float[] b = {5.0f, 6.0f, 7.0f, 8.0f};

        float[] result = new float[4];

        VectorSpecies<Float> species = FloatVector.SPECIES_128;

        int i = 0;

        for (; i <= a.length - species.length(); i += species.length()) {

            FloatVector av = FloatVector.fromArray(species, a, i);

            FloatVector bv = FloatVector.fromArray(species, b, i);

            FloatVector cv = av.add(bv);

            cv.intoArray(result, i);

        }

        for (; i < a.length; i++) {

            result[i] = a[i] + b[i];

        }

        System.out.println(Arrays.toString(result));

    }

}

In this example, the code performs a vectorized addition of two arrays of floating-point numbers using Vector API. The SPECIES_128 constant is used to specify the vector size (128 bits), and the code uses the FloatVector class to perform the vectorized addition. The intoArray method is used to write the results back to an output array.

Vector API can significantly improve the performance of mathematical computations, especially on modern hardware with vector units. However, it's important to note that not all hardware supports vector units, and the performance gains may vary depending on the size and type of data being processed. Additionally, the Vector API is still an experimental feature and subject to change in future Java releases.

Overall, Vector API is a powerful addition to Java 18 that can enable developers to write code that takes full advantage of modern hardware and delivers high-performance mathematical computations.