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 *

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package org.graalvm.compiler.loop.test;

import java.util.ListIterator;

import org.graalvm.compiler.core.common.CompilationIdentifier;

import org.graalvm.compiler.core.test.GraalCompilerTest;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.graph.iterators.NodeIterable;

import org.graalvm.compiler.java.ComputeLoopFrequenciesClosure;

import org.graalvm.compiler.loop.DefaultLoopPolicies;

import org.graalvm.compiler.loop.LoopEx;

import org.graalvm.compiler.loop.LoopFragmentInside;

import org.graalvm.compiler.loop.LoopsData;

import org.graalvm.compiler.loop.phases.LoopPartialUnrollPhase;

import org.graalvm.compiler.nodes.LoopBeginNode;

import org.graalvm.compiler.nodes.StructuredGraph;

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

import org.graalvm.compiler.options.OptionValues;

import org.graalvm.compiler.phases.BasePhase;

import org.graalvm.compiler.phases.OptimisticOptimizations;

import org.graalvm.compiler.phases.PhaseSuite;

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

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

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

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

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

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

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

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

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

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

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

import org.junit.Ignore;

import org.junit.Test;

import jdk.vm.ci.meta.ResolvedJavaMethod;

public class LoopPartialUnrollTest extends GraalCompilerTest {

    @Override

    protected void checkMidTierGraph(StructuredGraph graph) {

        NodeIterable<LoopBeginNode> loops = graph.getNodes().filter(LoopBeginNode.class);

        for (LoopBeginNode loop : loops) {

            if (loop.isMainLoop()) {

                return;

            }

        }

        fail("expected a main loop");

    }

    public static long sumWithEqualityLimit(int[] text) {

        long sum = 0;

        for (int i = 0; branchProbability(0.99, i != text.length); ++i) {

            sum += volatileInt;

        }

        return sum;

    }

    @Ignore("equality limits aren't working properly")

    @Test

    public void testSumWithEqualityLimit() {

        for (int i = -1; i < 128; i++) {

            int[] data = new int[i];

            test("sumWithEqualityLimit", data);

        }

    }

    @Test

    public void testLoopCarried() {

        for (int i = -1; i < 64; i++) {

            test("testLoopCarriedSnippet", i);

        }

    }

    @Test

    public void testLoopCarriedDuplication() {

        testDuplicateBody("testLoopCarriedReference", "testLoopCarriedSnippet");

    }

    static volatile int volatileInt = 3;

    public static int testLoopCarriedSnippet(int iterations) {

        int a = 0;

        int b = 0;

        int c = 0;

        for (int i = 0; branchProbability(0.99, i < iterations); i++) {

            int t1 = volatileInt;

            int t2 = a + b;

            c = b;

            b = a;

            a = t1 + t2;

        }

        return c;

    }

    public static int testLoopCarriedReference(int iterations) {

        int a = 0;

        int b = 0;

        int c = 0;

        for (int i = 0; branchProbability(0.99, i < iterations); i += 2) {

            int t1 = volatileInt;

            int t2 = a + b;

            c = b;

            b = a;

            a = t1 + t2;

            t1 = volatileInt;

            t2 = a + b;

            c = b;

            b = a;

            a = t1 + t2;

        }

        return c;

    }

    @Test

    public void testLoopCarried2() {

        for (int i = -1; i < 64; i++) {

            for (int j = -1; j < 64; j++) {

                test("testLoopCarried2Snippet", i, j);

            }

        }

        test("testLoopCarried2Snippet", Integer.MAX_VALUE - 32, Integer.MAX_VALUE);

        test("testLoopCarried2Snippet", Integer.MAX_VALUE - 4, Integer.MAX_VALUE);

        test("testLoopCarried2Snippet", Integer.MAX_VALUE, 0);

        test("testLoopCarried2Snippet", Integer.MIN_VALUE, Integer.MIN_VALUE + 32);

        test("testLoopCarried2Snippet", Integer.MIN_VALUE, Integer.MIN_VALUE + 4);

        test("testLoopCarried2Snippet", 0, Integer.MIN_VALUE);

    }

    public static int testLoopCarried2Snippet(int start, int end) {

        int a = 0;

        int b = 0;

        int c = 0;

        for (int i = start; branchProbability(0.99, i < end); i++) {

            int t1 = volatileInt;

            int t2 = a + b;

            c = b;

            b = a;

            a = t1 + t2;

        }

        return c;

    }

    public static long init = Runtime.getRuntime().totalMemory();

    private int x;

    private int z;

    public int[] testComplexSnippet(int d) {

        x = 3;

        int y = 5;

        z = 7;

        for (int i = 0; i < d; i++) {

            for (int j = 0; branchProbability(0.99, j < i); j++) {

                z += x;

            }

            y = x ^ z;

            if ((i & 4) == 0) {

                z--;

            } else if ((i & 8) == 0) {

                Runtime.getRuntime().totalMemory();

            }

        }

        return new int[]{x, y, z};

    }

    @Test

    public void testComplex() {

        for (int i = -1; i < 10; i++) {

            test("testComplexSnippet", i);

        }

        test("testComplexSnippet", 10);

        test("testComplexSnippet", 100);

        test("testComplexSnippet", 1000);

    }

    public static long testSignExtensionSnippet(long arg) {

        long r = 1;

        for (int i = 0; branchProbability(0.99, i < arg); i++) {

            r *= i;

        }

        return r;

    }

    @Test

    public void testSignExtension() {

        test("testSignExtensionSnippet", 9L);

    }

    @Override

    protected Suites createSuites(OptionValues opts) {

        Suites suites = super.createSuites(opts).copy();

        PhaseSuite<MidTierContext> mid = suites.getMidTier();

        ListIterator<BasePhase<? super MidTierContext>> iter = mid.findPhase(LoopPartialUnrollPhase.class);

        BasePhase<? super MidTierContext> partialUnoll = iter.previous();

        if (iter.previous().getClass() != FrameStateAssignmentPhase.class) {

            // Ensure LoopPartialUnrollPhase runs immediately after FrameStateAssignment, so it gets

            // priority over other optimizations in these tests.

            mid.findPhase(LoopPartialUnrollPhase.class).remove();

            ListIterator<BasePhase<? super MidTierContext>> fsa = mid.findPhase(FrameStateAssignmentPhase.class);

            fsa.add(partialUnoll);

        }

        return suites;

    }

    public void testGraph(String reference, String test) {

        StructuredGraph referenceGraph = buildGraph(reference, false);

        StructuredGraph testGraph = buildGraph(test, true);

        assertEquals(referenceGraph, testGraph, false, false);

    }

    @SuppressWarnings("try")

    public StructuredGraph buildGraph(String name, boolean partialUnroll) {

        CompilationIdentifier id = new CompilationIdentifier() {

            @Override

            public String toString(Verbosity verbosity) {

                return name;

            }

        };

        ResolvedJavaMethod method = getResolvedJavaMethod(name);

        OptionValues options = new OptionValues(getInitialOptions(), DefaultLoopPolicies.Options.UnrollMaxIterations, 2);

        StructuredGraph graph = parse(builder(method, StructuredGraph.AllowAssumptions.YES, id, options), getEagerGraphBuilderSuite());

        try (DebugContext.Scope buildScope = graph.getDebug().scope(name, method, graph)) {

            MidTierContext context = new MidTierContext(getProviders(), getTargetProvider(), OptimisticOptimizations.ALL, null);

            CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

            canonicalizer.apply(graph, context);

            new RemoveValueProxyPhase().apply(graph);

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

            new FloatingReadPhase().apply(graph);

            new DeadCodeEliminationPhase().apply(graph);

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

            ComputeLoopFrequenciesClosure.compute(graph);

            new GuardLoweringPhase().apply(graph, context);

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

            new FrameStateAssignmentPhase().apply(graph);

            new DeoptimizationGroupingPhase().apply(graph, context);

            canonicalizer.apply(graph, context);

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

            if (partialUnroll) {

                LoopsData dataCounted = new LoopsData(graph);

                dataCounted.detectedCountedLoops();

                for (LoopEx loop : dataCounted.countedLoops()) {

                    LoopFragmentInside newSegment = loop.inside().duplicate();

                    newSegment.insertWithinAfter(loop, null);

                }

                canonicalizer.apply(graph, getDefaultMidTierContext());

            }

            new DeadCodeEliminationPhase().apply(graph);

            canonicalizer.apply(graph, context);

            graph.getDebug().dump(DebugContext.BASIC_LEVEL, graph, "before compare");

            return graph;

        } catch (Throwable e) {

            throw getDebugContext().handle(e);

        }

    }

    public void testDuplicateBody(String reference, String test) {

        StructuredGraph referenceGraph = buildGraph(reference, false);

        StructuredGraph testGraph = buildGraph(test, true);

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        canonicalizer.apply(testGraph, getDefaultMidTierContext());

        canonicalizer.apply(referenceGraph, getDefaultMidTierContext());

        assertEquals(referenceGraph, testGraph);

    }

}