/*

 * Copyright (c) 2015, 2016, 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 org.graalvm.compiler.replacements;

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

import static org.graalvm.compiler.nodes.graphbuilderconf.IntrinsicContext.CompilationContext.INLINE_AFTER_PARSING;

import java.util.HashMap;

import java.util.Map;

import org.graalvm.compiler.bytecode.BytecodeProvider;

import org.graalvm.compiler.debug.Debug;

import org.graalvm.compiler.java.GraphBuilderPhase;

import org.graalvm.compiler.nodes.EncodedGraph;

import org.graalvm.compiler.nodes.GraphEncoder;

import org.graalvm.compiler.nodes.StructuredGraph;

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

import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderConfiguration;

import org.graalvm.compiler.nodes.graphbuilderconf.IntrinsicContext;

import org.graalvm.compiler.phases.OptimisticOptimizations;

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

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

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

import org.graalvm.compiler.phases.util.Providers;

import jdk.vm.ci.code.Architecture;

import jdk.vm.ci.meta.ResolvedJavaMethod;

/**

 * A graph decoder that provides all necessary encoded graphs on-the-fly (by parsing the methods and

 * encoding the graphs).

 */

public class CachingPEGraphDecoder extends PEGraphDecoder {

    protected final Providers providers;

    protected final GraphBuilderConfiguration graphBuilderConfig;

    protected final OptimisticOptimizations optimisticOpts;

    private final AllowAssumptions allowAssumptions;

    private final Map<ResolvedJavaMethod, EncodedGraph> graphCache;

    public CachingPEGraphDecoder(Providers providers, GraphBuilderConfiguration graphBuilderConfig, OptimisticOptimizations optimisticOpts, AllowAssumptions allowAssumptions,

                    Architecture architecture) {

        super(providers.getMetaAccess(), providers.getConstantReflection(), providers.getConstantFieldProvider(), providers.getStampProvider(), architecture);

        this.providers = providers;

        this.graphBuilderConfig = graphBuilderConfig;

        this.optimisticOpts = optimisticOpts;

        this.allowAssumptions = allowAssumptions;

        this.graphCache = new HashMap<>();

    }

    protected GraphBuilderPhase.Instance createGraphBuilderPhaseInstance(IntrinsicContext initialIntrinsicContext) {

        return new GraphBuilderPhase.Instance(providers.getMetaAccess(), providers.getStampProvider(), providers.getConstantReflection(), providers.getConstantFieldProvider(), graphBuilderConfig,

                        optimisticOpts, initialIntrinsicContext);

    }

    @SuppressWarnings("try")

    private EncodedGraph createGraph(ResolvedJavaMethod method, BytecodeProvider intrinsicBytecodeProvider) {

        StructuredGraph graph = new StructuredGraph(method, allowAssumptions, INVALID_COMPILATION_ID);

        try (Debug.Scope scope = Debug.scope("createGraph", graph)) {

            IntrinsicContext initialIntrinsicContext = intrinsicBytecodeProvider != null ? new IntrinsicContext(method, method, intrinsicBytecodeProvider, INLINE_AFTER_PARSING) : null;

            GraphBuilderPhase.Instance graphBuilderPhaseInstance = createGraphBuilderPhaseInstance(initialIntrinsicContext);

            graphBuilderPhaseInstance.apply(graph);

            PhaseContext context = new PhaseContext(providers);

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

            /*

             * ConvertDeoptimizeToGuardPhase reduces the number of merges in the graph, so that

             * fewer frame states will be created. This significantly reduces the number of nodes in

             * the initial graph.

             */

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

            EncodedGraph encodedGraph = GraphEncoder.encodeSingleGraph(graph, architecture);

            graphCache.put(method, encodedGraph);

            return encodedGraph;

        } catch (Throwable ex) {

            throw Debug.handle(ex);

        }

    }

    @Override

    protected EncodedGraph lookupEncodedGraph(ResolvedJavaMethod method, BytecodeProvider intrinsicBytecodeProvider) {

        EncodedGraph result = graphCache.get(method);

        if (result == null && method.hasBytecodes()) {

            result = createGraph(method, intrinsicBytecodeProvider);

        }

        return result;

    }

}