/*

 * Copyright (c) 2012, 2012, 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.loop;

import org.graalvm.compiler.core.common.cfg.Loop;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.graph.Graph;

import org.graalvm.compiler.graph.Graph.DuplicationReplacement;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.graph.NodeBitMap;

import org.graalvm.compiler.nodes.EndNode;

import org.graalvm.compiler.nodes.FixedNode;

import org.graalvm.compiler.nodes.LoopBeginNode;

import org.graalvm.compiler.nodes.LoopExitNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.cfg.Block;

public class LoopFragmentWhole extends LoopFragment {

    public LoopFragmentWhole(LoopEx loop) {

        super(loop);

    }

    public LoopFragmentWhole(LoopFragmentWhole original) {

        super(null, original);

    }

    @Override

    public LoopFragmentWhole duplicate() {

        LoopFragmentWhole loopFragmentWhole = new LoopFragmentWhole(this);

        loopFragmentWhole.reify();

        return loopFragmentWhole;

    }

    private void reify() {

        assert this.isDuplicate();

        patchNodes(null);

        mergeEarlyExits();

    }

    @Override

    public NodeBitMap nodes() {

        if (nodes == null) {

            Loop<Block> loop = loop().loop();

            nodes = LoopFragment.computeNodes(graph(), LoopFragment.toHirBlocks(loop.getBlocks()), LoopFragment.toHirExits(loop.getExits()));

        }

        return nodes;

    }

    @Override

    protected ValueNode prim(ValueNode b) {

        return getDuplicatedNode(b);

    }

    @Override

    protected DuplicationReplacement getDuplicationReplacement() {

        final FixedNode entry = loop().entryPoint();

        final Graph graph = this.graph();

        return new DuplicationReplacement() {

            private EndNode endNode;

            @Override

            public Node replacement(Node o) {

                if (o == entry) {

                    if (endNode == null) {

                        endNode = graph.add(new EndNode());

                    }

                    return endNode;

                }

                return o;

            }

        };

    }

    public FixedNode entryPoint() {

        if (isDuplicate()) {

            LoopBeginNode newLoopBegin = getDuplicatedNode(original().loop().loopBegin());

            return newLoopBegin.forwardEnd();

        }

        return loop().entryPoint();

    }

    @Override

    protected void finishDuplication() {

        // TODO (gd) ?

    }

    void cleanupLoopExits() {

        LoopBeginNode loopBegin = original().loop().loopBegin();

        assert nodes == null || nodes.contains(loopBegin);

        StructuredGraph graph = loopBegin.graph();

        if (graph.getGuardsStage() == StructuredGraph.GuardsStage.AFTER_FSA) {

            // After FrameStateAssignment ControlFlowGraph treats loop exits differently which means

            // that the LoopExitNodes can be in a block which post dominates the true loop exit. For

            // cloning to work right they must agree.

            EconomicSet<LoopExitNode> exits = EconomicSet.create();

            for (Block exitBlock : original().loop().loop().getExits()) {

                LoopExitNode exitNode = exitBlock.getLoopExit();

                if (exitNode == null) {

                    exitNode = graph.add(new LoopExitNode(loopBegin));

                    graph.addAfterFixed(exitBlock.getBeginNode(), exitNode);

                    if (nodes != null) {

                        nodes.mark(exitNode);

                    }

                    graph.getDebug().dump(DebugContext.VERBOSE_LEVEL, graph, "Adjusting loop exit node for %s", loopBegin);

                }

                exits.add(exitNode);

            }

            for (LoopExitNode exitNode : loopBegin.loopExits()) {

                if (!exits.contains(exitNode)) {

                    if (nodes != null) {

                        nodes.clear(exitNode);

                    }

                    graph.removeFixed(exitNode);

                }

            }

        }

    }

    @Override

    protected void beforeDuplication() {

        cleanupLoopExits();

    }

    @Override

    public void insertBefore(LoopEx loop) {

        // TODO Auto-generated method stub

    }

}