/*
 * Copyright (c) 2014, 2015, 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
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package org.graalvm.compiler.hotspot.amd64.test;

import org.junit.Assert;
import org.junit.Assume;
import org.junit.Test;

import org.graalvm.compiler.core.common.GraalOptions;
import org.graalvm.compiler.hotspot.nodes.CompressionNode;
import org.graalvm.compiler.hotspot.test.HotSpotGraalCompilerTest;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.calc.IsNullNode;
import org.graalvm.compiler.options.OptionValue;
import org.graalvm.compiler.options.OptionValue.OverrideScope;

import jdk.vm.ci.meta.ResolvedJavaMethod;

/**
 * Ensures that frame omission works in cases where it is expected to.
 */
public class CompressedNullCheckTest extends HotSpotGraalCompilerTest {

    private static final class Container {
        Integer i;
    }

    public static void testSnippet(Container c) {
        c.i.intValue();
    }

    @SuppressWarnings("try")
    private void testImplicit(Integer i) {
        Assume.assumeTrue(runtime().getVMConfig().useCompressedOops);

        Container c = new Container();
        c.i = i;

        try (OverrideScope s = OptionValue.override(GraalOptions.OptImplicitNullChecks, true)) {
            ResolvedJavaMethod method = getResolvedJavaMethod("testSnippet");
            Result expect = executeExpected(method, null, c);

            // make sure we don't get a profile that removes the implicit null check
            method.reprofile();

            Result actual = executeActual(method, null, c);
            assertEquals(expect, actual);
        }
    }

    @SuppressWarnings("try")
    private void testExplicit(Integer i) {
        Assume.assumeTrue(runtime().getVMConfig().useCompressedOops);

        Container c = new Container();
        c.i = i;

        try (OverrideScope s = OptionValue.override(GraalOptions.OptImplicitNullChecks, false)) {
            test("testSnippet", c);
        }
    }

    @Test
    public void implicit() {
        testImplicit(new Integer(1));
    }

    @Test
    public void implicitNull() {
        testImplicit(null);
    }

    @Test
    public void explicit() {
        testExplicit(new Integer(1));
    }

    @Test
    public void explicitNull() {
        testExplicit(null);
    }

    @Override
    protected boolean checkMidTierGraph(StructuredGraph graph) {
        int count = 0;
        for (IsNullNode isNull : graph.getNodes().filter(IsNullNode.class).snapshot()) {
            ValueNode value = isNull.getValue();
            if (value instanceof CompressionNode) {
                count++;
                isNull.replaceFirstInput(value, ((CompressionNode) value).getValue());
            }
        }
        Assert.assertEquals("graph should contain exactly one IsNullNode", 1, count);
        return super.checkMidTierGraph(graph);
    }
}