/*
* Copyright (c) 2009, 2011, 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.
*
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package com.oracle.max.graal.nodes;
import com.oracle.max.graal.graph.*;
import com.oracle.max.graal.nodes.spi.*;
import com.oracle.max.graal.nodes.type.*;
/**
* The {@code AnchorNode} can be used a lower bound for a Guard. It can also be used as an upper bound if no other FixedNode can be used for that purpose.
*/
public final class AnchorNode extends FixedWithNextNode implements LIRLowerable, Canonicalizable {
@Input(notDataflow = true) private final NodeInputList<GuardNode> guards = new NodeInputList<GuardNode>(this);
public AnchorNode() {
super(StampFactory.illegal());
}
public void addGuard(GuardNode x) {
guards.add(x);
}
@Override
public Node canonical(CanonicalizerTool tool) {
if (this.usages().size() == 0 && guards.size() == 0) {
return next();
}
return this;
}
@Override
public void generate(LIRGeneratorTool gen) {
// TODO is it necessary to do something for the "guards" list here?
// Currently, there is nothing to emit since anchors are only a structural element with no execution semantics.
}
}