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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

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 *

 * 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.graalvm.compiler.core.test;

import java.lang.reflect.Field;

import org.junit.Assert;

import org.junit.Test;

import org.graalvm.compiler.api.directives.GraalDirectives;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;

import org.graalvm.compiler.nodes.extended.UnsafeAccessNode;

import org.graalvm.compiler.nodes.memory.ReadNode;

import org.graalvm.compiler.nodes.memory.WriteNode;

import org.graalvm.compiler.nodes.spi.LoweringTool;

import org.graalvm.compiler.phases.common.CanonicalizerPhase;

import org.graalvm.compiler.phases.common.LoweringPhase;

import org.graalvm.compiler.phases.tiers.PhaseContext;

import org.graalvm.compiler.virtual.phases.ea.EarlyReadEliminationPhase;

import org.graalvm.compiler.virtual.phases.ea.PartialEscapePhase;

import sun.misc.Unsafe;

public class UnsafeReadEliminationTest extends GraalCompilerTest {

    public static final Unsafe UNSAFE;

    static {

        try {

            Field theUnsafe = Unsafe.class.getDeclaredField("theUnsafe");

            theUnsafe.setAccessible(true);

            UNSAFE = (Unsafe) theUnsafe.get(Unsafe.class);

        } catch (Exception e) {

            throw new RuntimeException("Exception while trying to get Unsafe", e);

        }

    }

    public static long[] Memory = new long[]{1, 2};

    public static double SideEffectD;

    public static double SideEffectL;

    public static long test1Snippet(double a) {

        final Object m = Memory;

        if (a > 0) {

            UNSAFE.putDouble(m, (long) Unsafe.ARRAY_LONG_BASE_OFFSET, a);

        } else {

            SideEffectL = UNSAFE.getLong(m, (long) Unsafe.ARRAY_LONG_BASE_OFFSET);

        }

        return UNSAFE.getLong(m, (long) Unsafe.ARRAY_LONG_BASE_OFFSET);

    }

    public static class A {

        long[][] o;

        long[][] p;

    }

    public static Object test2Snippet(A a, int c) {

        Object phi = null;

        if (c != 0) {

            long[][] r = a.o;

            phi = r;

            UNSAFE.putDouble(r, (long) Unsafe.ARRAY_LONG_BASE_OFFSET, 12d);

        } else {

            long[][] r = a.p;

            phi = r;

            UNSAFE.putLong(r, (long) Unsafe.ARRAY_LONG_BASE_OFFSET, 123);

        }

        GraalDirectives.controlFlowAnchor();

        SideEffectD = UNSAFE.getDouble(phi, (long) Unsafe.ARRAY_LONG_BASE_OFFSET);

        return phi;

    }

    @Test

    public void test01() {

        StructuredGraph graph = parseEager("test1Snippet", AllowAssumptions.NO);

        testEarlyReadElimination(graph, 3, 2);

    }

    @Test

    public void test02() {

        StructuredGraph graph = parseEager("test1Snippet", AllowAssumptions.NO);

        testPartialEscapeReadElimination(graph, 3, 2);

    }

    @Test

    public void test03() {

        StructuredGraph graph = parseEager("test2Snippet", AllowAssumptions.NO);

        testEarlyReadElimination(graph, 3, 3);

    }

    @Test

    public void test04() {

        StructuredGraph graph = parseEager("test2Snippet", AllowAssumptions.NO);

        testEarlyReadElimination(graph, 3, 3);

    }

    public void testEarlyReadElimination(StructuredGraph graph, int reads, int writes) {

        PhaseContext context = getDefaultHighTierContext();

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        canonicalizer.apply(graph, context);

        new EarlyReadEliminationPhase(canonicalizer).apply(graph, context);

        Assert.assertEquals(3, graph.getNodes().filter(UnsafeAccessNode.class).count());

        // after lowering the same applies for reads and writes

        new LoweringPhase(canonicalizer, LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context);

        canonicalizer.apply(graph, context);

        new EarlyReadEliminationPhase(canonicalizer).apply(graph, context);

        Assert.assertEquals(reads, graph.getNodes().filter(ReadNode.class).count());

        Assert.assertEquals(writes, graph.getNodes().filter(WriteNode.class).count());

    }

    public void testPartialEscapeReadElimination(StructuredGraph graph, int reads, int writes) {

        PhaseContext context = getDefaultHighTierContext();

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        canonicalizer.apply(graph, context);

        new PartialEscapePhase(true, true, canonicalizer, null).apply(graph, context);

        Assert.assertEquals(3, graph.getNodes().filter(UnsafeAccessNode.class).count());

        // after lowering the same applies for reads and writes

        new LoweringPhase(canonicalizer, LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context);

        canonicalizer.apply(graph, context);

        new PartialEscapePhase(true, true, canonicalizer, null).apply(graph, context);

        Assert.assertEquals(reads, graph.getNodes().filter(ReadNode.class).count());

        Assert.assertEquals(writes, graph.getNodes().filter(WriteNode.class).count());

    }

}