/*

 * Copyright (c) 2012, 2018, 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.nodes;

import org.graalvm.compiler.graph.Node;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.graph.spi.Canonicalizable;

import org.graalvm.compiler.graph.spi.CanonicalizerTool;

import org.graalvm.compiler.nodeinfo.NodeInfo;

import org.graalvm.compiler.nodes.extended.GuardingNode;

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

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

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

import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;

@NodeInfo(nameTemplate = "Proxy({i#value})")

public final class ValueProxyNode extends ProxyNode implements Canonicalizable, Virtualizable, ValueProxy {

    public static final NodeClass<ValueProxyNode> TYPE = NodeClass.create(ValueProxyNode.class);

    @Input ValueNode value;

    private final boolean loopPhiProxy;

    public ValueProxyNode(ValueNode value, LoopExitNode loopExit) {

        super(TYPE, value.stamp(NodeView.DEFAULT), loopExit);

        this.value = value;

        loopPhiProxy = loopExit.loopBegin().isPhiAtMerge(value);

    }

    @Override

    public ValueNode value() {

        return value;

    }

    @Override

    public boolean inferStamp() {

        return updateStamp(value.stamp(NodeView.DEFAULT));

    }

    @Override

    public Node canonical(CanonicalizerTool tool) {

        ValueNode curValue = value;

        if (curValue.isConstant()) {

            return curValue;

        }

        if (loopPhiProxy && !loopExit.loopBegin().isPhiAtMerge(curValue)) {

            return curValue;

        }

        return this;

    }

    @Override

    public void virtualize(VirtualizerTool tool) {

        ValueNode alias = tool.getAlias(value);

        if (alias instanceof VirtualObjectNode) {

            tool.replaceWithVirtual((VirtualObjectNode) alias);

        }

    }

    @Override

    public ValueNode getOriginalNode() {

        return value();

    }

    @Override

    public GuardingNode getGuard() {

        return this.proxyPoint();

    }

}