/*
 * Copyright (c) 2014, 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.
 *
 * 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.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */
package org.openjdk.bench.java.lang;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.CompilerControl;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Param;
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 java.util.Random;
import java.util.concurrent.TimeUnit;

@BenchmarkMode(Mode.AverageTime)
@OutputTimeUnit(TimeUnit.NANOSECONDS)
@State(Scope.Thread)
public class MathBench {

    @Param("0")
    public long seed;

    public int dividend;
    public int divisor;

    public long longDividend;
    public long longDivisor;

    @Setup
    public void setupValues() {
        Random random = new Random(seed);
        dividend = Math.abs(random.nextInt() + 4711);
        divisor  = Math.abs(random.nextInt(dividend) + 17);
        longDividend = Math.abs(random.nextLong() + 4711L);
        longDivisor  = Math.abs(random.nextLong() + longDividend);
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public int floorModIntIntPositive() {
        return Math.floorMod(dividend, divisor);
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public int floorModIntInt() {
        return Math.floorMod( dividend,  divisor) +
               Math.floorMod( dividend, -divisor) +
               Math.floorMod(-dividend,  divisor) +
               Math.floorMod(-dividend, -divisor);
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public int floorModLongInt() {
        return Math.floorMod( longDividend,  divisor) +
               Math.floorMod( longDividend, -divisor) +
               Math.floorMod(-longDividend,  divisor) +
               Math.floorMod(-longDividend, -divisor);
    }

    @Benchmark
    @CompilerControl(CompilerControl.Mode.DONT_INLINE)
    public long floorModLongLong() {
        return Math.floorMod( longDividend,  longDivisor) +
               Math.floorMod( longDividend, -longDivisor) +
               Math.floorMod(-longDividend,  longDivisor) +
               Math.floorMod(-longDividend, -longDivisor);
    }

}
