Loop JMH Test

LoopTest.java

package com.denison;

import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.TimeUnit;

/**
 * @author Yuri Denison
 * @since 23.10.2016
 */
@State(Scope.Benchmark)
@Warmup(iterations = 5, timeUnit = TimeUnit.NANOSECONDS)
@Measurement(iterations = 10, timeUnit = TimeUnit.NANOSECONDS)
@Fork(value = 1)
@BenchmarkMode(Mode.Throughput)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
public class LoopTest {
    private static final int RUNS = 1000;
    private static final int SIZE = 1_000_000_0;

    private static final List<Integer> VALUES = new ArrayList<>(SIZE);

    static {
        Collections.fill(VALUES, 1);
    }

    @Benchmark
    @OperationsPerInvocation(RUNS)
    public long traditionalLoop() {
        long sum = 0;
        for (int i = 0; i < VALUES.size(); i++) {
            sum += VALUES.get(i);
        }
        return sum;
    }

    @Benchmark
    @OperationsPerInvocation(RUNS)
    public long traditionalLoopOptimized() {
        long sum = 0;
        int size = VALUES.size();
        for (int i = 0; i < size; i++) {
            sum += VALUES.get(i);
        }
        return sum;
    }

    @Benchmark
    @OperationsPerInvocation(RUNS)
    public long foreachLoop() {
        long sum = 0;
        for (int value : VALUES) {
            sum += value;
        }
        return sum;
    }



    public static void main(String[] args) throws RunnerException {
        Options opt = new OptionsBuilder()
                .include(".*" + LoopTest.class.getSimpleName() + ".*")
                .build();

        new Runner(opt).run();
    }
}

Results.txt

# JMH 1.15 (released 23 days ago)
# VM version: JDK 1.8.0_102, VM 25.102-b14
# VM invoker: /Library/Java/JavaVirtualMachines/jdk1.8.0_102.jdk/Contents/Home/jre/bin/java
# VM options: -Didea.launcher.port=7537 -Didea.launcher.bin.path=/Applications/IntelliJ IDEA.app/Contents/bin -Dfile.encoding=UTF-8
# Warmup: 5 iterations, 1 s each
# Measurement: 10 iterations, 1 s each
# Timeout: 10 min per iteration
# Threads: 1 thread, will synchronize iterations
# Benchmark mode: Throughput, ops/time

Benchmark                           Mode  Cnt    Score    Error   Units
LoopTest.foreachLoop               thrpt   10  280.758 ± 11.071  ops/ns
LoopTest.traditionalLoop           thrpt   10  320.631 ± 14.032  ops/ns
LoopTest.traditionalLoopOptimized  thrpt   10  311.157 ± 15.439  ops/ns