/*

 * Copyright (c) 2011, 2019, 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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 * questions.

 */

package org.graalvm.compiler.core.test;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.nodes.GuardNode;

import org.graalvm.compiler.nodes.StructuredGraph;

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

import org.graalvm.compiler.nodes.java.InstanceOfNode;

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

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

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

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

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

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

import org.junit.Assert;

import org.junit.Test;

/**

 * Collection of tests for {@link org.graalvm.compiler.phases.common.ConditionalEliminationPhase}

 * including those that triggered bugs in this phase.

 */

public class ConditionalEliminationTest2 extends ConditionalEliminationTestBase {

    public static Object field;

    static class Entry {

        final String name;

        Entry(String name) {

            this.name = name;

        }

    }

    static class EntryWithNext extends Entry {

        EntryWithNext(String name, Entry next) {

            super(name);

            this.next = next;

        }

        final Entry next;

    }

    static class A {

    }

    static class B extends A {

    }

    static class C extends A {

    }

    public static Entry search(Entry start, String name, Entry alternative) {

        Entry current = start;

        do {

            while (current instanceof EntryWithNext) {

                if (name != null && current.name == name) {

                    current = null;

                } else {

                    Entry next = ((EntryWithNext) current).next;

                    current = next;

                }

            }

            if (current != null) {

                if (current.name.equals(name)) {

                    return current;

                }

            }

            if (current == alternative) {

                return null;

            }

            current = alternative;

        } while (true);

    }

    public static int testRedundantComparesSnippet(int[] array) {

        if (array == null) {

            return 0;

        }

        return array[0] + array[1] + array[2] + array[3];

    }

    @Test

    public void testRedundantCompares() {

        StructuredGraph graph = parseEager("testRedundantComparesSnippet", AllowAssumptions.YES);

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        CoreProviders context = getProviders();

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

        canonicalizer.apply(graph, context);

        new FloatingReadPhase().apply(graph);

        new ConditionalEliminationPhase(true).apply(graph, context);

        canonicalizer.apply(graph, context);

        assertDeepEquals(1, graph.getNodes().filter(GuardNode.class).count());

    }

    public static String testInstanceOfCheckCastSnippet(Object e) {

        if (e instanceof Entry) {

            return ((Entry) e).name;

        }

        return null;

    }

    @Test

    public void testInstanceOfCheckCastLowered() {

        StructuredGraph graph = parseEager("testInstanceOfCheckCastSnippet", AllowAssumptions.YES);

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        CoreProviders context = getProviders();

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

        canonicalizer.apply(graph, context);

        new ConditionalEliminationPhase(true).apply(graph, context);

        canonicalizer.apply(graph, context);

        assertDeepEquals(0, graph.getNodes().filter(GuardNode.class).count());

    }

    private void checkInstanceOfCount(String methodName, int count) {

        StructuredGraph graph = parseEager(methodName, AllowAssumptions.YES);

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        CoreProviders context = getProviders();

        canonicalizer.apply(graph, context);

        new ConditionalEliminationPhase(true).apply(graph, context);

        getDebugContext().dump(DebugContext.BASIC_LEVEL, graph, "After ConditionalEliminationPhase");

        canonicalizer.apply(graph, context);

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

    }

    public static A testRedundantInstanceOfClass(Object value) {

        if (value != null && value.getClass() == A.class) {

            return (A) value;

        }

        return null;

    }

    public static Object testRedundantInstanceOfArray(Object value) {

        if (value != null && value.getClass() == Object[].class) {

            return ((Object[]) value)[0];

        }

        return null;

    }

    public static boolean testRedundantInstanceOfPrecise(Object value) {

        if (value != null && value.getClass() == A.class) {

            return value instanceof A;

        }

        return false;

    }

    public static boolean testRedundantInstanceOfImplicitNonNull(Object value) {

        if (value.getClass() == A.class) {

            return value instanceof A;

        }

        return false;

    }

    @Test

    public void testRedundantInstanceOf() {

        checkInstanceOfCount("testRedundantInstanceOfClass", 1);

        checkInstanceOfCount("testRedundantInstanceOfArray", 1);

        checkInstanceOfCount("testRedundantInstanceOfPrecise", 1);

        checkInstanceOfCount("testRedundantInstanceOfImplicitNonNull", 1);

    }

    public static boolean testNonRedundantInstanceOfClass(Object value) {

        if (value instanceof A) {

            return (value != null && value.getClass() == A.class);

        }

        return false;

    }

    public static boolean testNonRedundantInstanceOfArray(Object value) {

        if (value instanceof Object[]) {

            return (value != null && value.getClass() == Object[].class);

        }

        return false;

    }

    public static boolean testNonRedundantInstanceOfImplicitNonNull(Object value) {

        if (value instanceof Object[]) {

            return value.getClass() == Object[].class;

        }

        return false;

    }

    @Test

    public void testNonRedundantInstanceOf() {

        checkInstanceOfCount("testNonRedundantInstanceOfClass", 2);

        checkInstanceOfCount("testNonRedundantInstanceOfArray", 2);

        checkInstanceOfCount("testNonRedundantInstanceOfImplicitNonNull", 2);

    }

}