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 * Copyright (c) 2012, 2021, 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * 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.nodes.loop;

import org.graalvm.compiler.core.common.cfg.Loop;
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.ValueNode;
import org.graalvm.compiler.nodes.cfg.HIRBlock;

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<HIRBlock> loop = loop().loop();
            NodeBitMap loopNodes = graph().createNodeBitMap();
            LoopFragment.computeNodes(loopNodes, graph(), loop(), LoopFragment.toHirBlocks(loop.getBlocks()), LoopFragment.toHirBlocks(loop.getLoopExits()));
            nodes = loopNodes;
        }
        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 beforeDuplication() {
        // nothing to do
    }

    @Override
    public void insertBefore(LoopEx loop) {
        // nothing to do
    }
}
