/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
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package org.openjdk.jmh.samples;

import java.util.Random;
import java.util.concurrent.TimeUnit;

import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Fork;
import org.openjdk.jmh.annotations.GenerateMicroBenchmark;
import org.openjdk.jmh.annotations.Measurement;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OperationsPerInvocation;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Threads;
import org.openjdk.jmh.annotations.Warmup;

@OutputTimeUnit(TimeUnit.NANOSECONDS)
@BenchmarkMode(Mode.AverageTime)
@OperationsPerInvocation(JmhMaxBenchmark.N)
@Warmup(iterations = 10, time = 1)
@Measurement(iterations = 10, time = 1)
@State(Scope.Thread)
@Threads(1)
@Fork(10)
public class JmhMaxBenchmark {
	protected static final int N = 1<<10;
	private final int[] table = new int[N];

	@Setup public void setUp() {
		final Random random = new Random();
		for (int i=0; i<table.length; ++i) table[i] = random.nextInt();
	}

	@GenerateMicroBenchmark public int intrinsic() {
		int result = Integer.MIN_VALUE;
		for (final int x : table) result = Math.max(result, x);
		return result;
	}

	@GenerateMicroBenchmark public int own() {
		int result = Integer.MIN_VALUE;
		for (final int x : table) result = max(result, x);
		return result;
	}

	private int max(int a, int b) {
		return (a >= b) ? a : b;
	}
}