package com.bellsw.simple;

import java.util.concurrent.TimeUnit;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;
import org.openjdk.jmh.annotations.OperationsPerInvocation;

@BenchmarkMode(Mode.AverageTime)
@Warmup(iterations = 20, time = 1, timeUnit = TimeUnit.SECONDS)
@Measurement(iterations = 5, time = 1, timeUnit = TimeUnit.SECONDS)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@Fork(3)
@State(Scope.Thread)
public class MathBench {
    @Benchmark
    @Threads(1)
    @OperationsPerInvocation(1000)
    public double usualPowArray() {
        double X = 0.7d; // any value
        double accum = 0.0d;
        for (int i = 0; i < 1000; i++) {
            accum += Math.pow(X, X); // X^X
            X+= 0.5d;
        }
        return accum;
    }

    @Benchmark
    @Threads(1)
    @OperationsPerInvocation(1000)
    public double usualSinSmallArg() {
        double X = 0.0d;
        double accum = 0.0d;
        for (int i = 0; i < 1000; i++) {
            accum += Math.sin(X);
            X+= 0.00001d;
        }
        return accum;
    }

    @Benchmark
    @Threads(1)
    @OperationsPerInvocation(1000)
    public double usualSinMediumArg() {
        double X = 100.0d;
        double accum = 0.0d;
        for (int i = 0; i < 1000; i++) {
            accum += Math.sin(X);
            X+= 1.0d;
        }
        return accum;
    }

    @Benchmark
    @Threads(1)
    @OperationsPerInvocation(1000)
    public double usualSinLargeArg() {
        double X = 1000000000.0d;
        double accum = 0.0d;
        for (int i = 0; i < 1000; i++) {
            accum += Math.sin(X);
            X+= 1000.0d;
        }
        return accum;
    }

    @Benchmark
    @Threads(1)
    @OperationsPerInvocation(1000)
    public double usualLog() {
        double X = 5.0d;
        double accum = 0.0d;
        for (int i = 0; i < 1000; i++) {
            accum += Math.log(X);
            X+= 1.0d;
        }
        return accum;
    }
}