| /* |
| * Copyright (c) 2011, 2015, 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.extended; |
| |
| import static org.graalvm.compiler.nodeinfo.InputType.Anchor; |
| import static org.graalvm.compiler.nodeinfo.InputType.Guard; |
| import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0; |
| import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0; |
| |
| import org.graalvm.compiler.core.common.type.StampFactory; |
| import org.graalvm.compiler.graph.NodeClass; |
| import org.graalvm.compiler.graph.spi.Simplifiable; |
| import org.graalvm.compiler.graph.spi.SimplifierTool; |
| import org.graalvm.compiler.nodeinfo.NodeInfo; |
| import org.graalvm.compiler.nodes.AbstractBeginNode; |
| import org.graalvm.compiler.nodes.FixedNode; |
| import org.graalvm.compiler.nodes.FixedWithNextNode; |
| import org.graalvm.compiler.nodes.GuardNode; |
| import org.graalvm.compiler.nodes.ValueNode; |
| import org.graalvm.compiler.nodes.calc.IsNullNode; |
| import org.graalvm.compiler.nodes.memory.FixedAccessNode; |
| import org.graalvm.compiler.nodes.spi.LIRLowerable; |
| import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool; |
| import org.graalvm.compiler.nodes.spi.Virtualizable; |
| import org.graalvm.compiler.nodes.spi.VirtualizerTool; |
| import org.graalvm.compiler.nodes.util.GraphUtil; |
| import org.graalvm.compiler.nodes.virtual.VirtualObjectNode; |
| |
| /** |
| * The ValueAnchor instruction keeps non-CFG (floating) nodes above a certain point in the graph. |
| */ |
| @NodeInfo(allowedUsageTypes = {Anchor, Guard}, cycles = CYCLES_0, size = SIZE_0) |
| public final class ValueAnchorNode extends FixedWithNextNode implements LIRLowerable, Simplifiable, Virtualizable, AnchoringNode, GuardingNode { |
| |
| public static final NodeClass<ValueAnchorNode> TYPE = NodeClass.create(ValueAnchorNode.class); |
| @OptionalInput(Guard) ValueNode anchored; |
| |
| public ValueAnchorNode(ValueNode value) { |
| super(TYPE, StampFactory.forVoid()); |
| this.anchored = value; |
| } |
| |
| @Override |
| public void generate(NodeLIRBuilderTool gen) { |
| // Nothing to emit, since this node is used for structural purposes only. |
| } |
| |
| public ValueNode getAnchoredNode() { |
| return anchored; |
| } |
| |
| @Override |
| public void simplify(SimplifierTool tool) { |
| while (next() instanceof ValueAnchorNode) { |
| ValueAnchorNode nextAnchor = (ValueAnchorNode) next(); |
| if (nextAnchor.anchored == anchored || nextAnchor.anchored == null) { |
| // two anchors for the same anchored -> coalesce |
| // nothing anchored on the next anchor -> coalesce |
| nextAnchor.replaceAtUsages(this); |
| GraphUtil.removeFixedWithUnusedInputs(nextAnchor); |
| } else { |
| break; |
| } |
| } |
| if (tool.allUsagesAvailable() && hasNoUsages() && next() instanceof FixedAccessNode) { |
| FixedAccessNode currentNext = (FixedAccessNode) next(); |
| if (currentNext.getGuard() == anchored) { |
| GraphUtil.removeFixedWithUnusedInputs(this); |
| return; |
| } else if (currentNext.getGuard() == null && anchored instanceof GuardNode && ((GuardNode) anchored).getCondition() instanceof IsNullNode) { |
| // coalesce null check guards into subsequent read/write |
| currentNext.setGuard((GuardingNode) anchored); |
| tool.addToWorkList(next()); |
| return; |
| } |
| } |
| |
| if (anchored != null && (anchored.isConstant() || anchored instanceof FixedNode)) { |
| // anchoring fixed nodes and constants is useless |
| removeAnchoredNode(); |
| } |
| |
| if (anchored == null && hasNoUsages()) { |
| // anchor is not necessary any more => remove. |
| GraphUtil.removeFixedWithUnusedInputs(this); |
| } |
| } |
| |
| @Override |
| public void virtualize(VirtualizerTool tool) { |
| if (anchored == null || anchored instanceof AbstractBeginNode) { |
| tool.delete(); |
| } else { |
| ValueNode alias = tool.getAlias(anchored); |
| if (alias instanceof VirtualObjectNode) { |
| tool.delete(); |
| } |
| } |
| } |
| |
| public void removeAnchoredNode() { |
| this.updateUsages(anchored, null); |
| this.anchored = null; |
| } |
| } |