/*
 * Copyright (c) 2015, 2020, 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 micro.benchmarks;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Level;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;

Benchmarks cost of guarded intrinsics at indirect call sites.
/**
 * Benchmarks cost of guarded intrinsics at indirect call sites.
 */
public class GuardedIntrinsicBenchmark extends BenchmarkBase {

    public static class HashcodeState {
        public Object val1;
        public Object val2;

        public HashcodeState(Object val1, Object val2) {
            this.val1 = val1;
            this.val2 = val2;
        }

        int getNextHashCode() {
            return val1.hashCode();
        }

        protected void swap() {
            Object tmp = val1;
            val1 = val2;
            val2 = tmp;
        }
    }

    
Objects that all override Object.hashCode(). The objects used have hashCode implementations that are basically getters as we want to measure the overhead of hashCode dispatch, not the cost of the hashCode implementation. /**
     * Objects that all override {@link Object#hashCode()}. The objects used have hashCode
     * implementations that are basically getters as we want to measure the overhead of hashCode
     * dispatch, not the cost of the hashCode implementation.
     */
    @State(Scope.Benchmark)
    public static class OverrideHashcode extends HashcodeState {
        public OverrideHashcode() {
            super(Short.valueOf((short) 100), Integer.valueOf(42));
        }

        @Setup(Level.Invocation)
        public void beforeInvocation() {
            swap();
        }
    }

    @Benchmark
    public int overrideHashCode(OverrideHashcode state) {
        return state.getNextHashCode();
    }

    
Objects that do not override Object.hashCode(). /**
     * Objects that do not override {@link Object#hashCode()}.
     */
    @State(Scope.Benchmark)
    public static class InheritHashcode extends HashcodeState {
        public InheritHashcode() {
            super(Class.class, Runtime.getRuntime());
        }

        @Setup(Level.Invocation)
        public void beforeInvocation() {
            swap();
        }
    }

    @Benchmark
    public int inheritHashCode(InheritHashcode state) {
        return state.getNextHashCode();
    }

    
Some objects that override Object.hashCode() and some that don't. /**
     * Some objects that override {@link Object#hashCode()} and some that don't.
     */
    @State(Scope.Benchmark)
    public static class MixedHashcode extends HashcodeState {
        public MixedHashcode() {
            super(Short.valueOf((short) 100), Runtime.getRuntime());
        }

        @Setup(Level.Invocation)
        public void beforeInvocation() {
            swap();
        }
    }

    @Benchmark
    public int mixedHashCode(MixedHashcode state) {
        return state.getNextHashCode();
    }
}