JDK-8350720.java

import org.openjdk.jmh.annotations.*;
import java.util.concurrent.TimeUnit;

@State(Scope.Thread)
@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Warmup(iterations = 5, time = 10, timeUnit = TimeUnit.SECONDS)
@Measurement(iterations = 5, time = 10, timeUnit = TimeUnit.SECONDS)
@Fork(3)
public class NestedLoops {
    public static final int N = 256;

    @Benchmark
    public static void loop1() {
        double dArr[] = new double[N];
        for (int i = 0; i < 10; i++) {
            final int tmp = i;
            for (int k = 0; k < i; k++) {
                i += 100000;
            }
            for (int p = 0; p < dArr.length; p++) {
                dArr[p] = (p % 2 == 0) ? -3.1 + p : -3.1 - p;
            }
            i = tmp;
        }
    }

    @Benchmark
    public static void loop2() {
        double dArr[] = new double[N];
        for (int i = 0; i < 10; i++) {
            final int tmp = i;
            // for (int k = 0; k < i; k++) {
            // i += 100000;
            // }
            for (int p = 0; p < dArr.length; p++) {
                dArr[p] = (p % 2 == 0) ? -3.1 + p : -3.1 - p;
            }
            i = tmp;
        }
    }
}