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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * This code is free software; you can redistribute it and/or modify it
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 * 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).
 *
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 * 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;

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.Stamp;
import org.graalvm.compiler.graph.IterableNodeType;
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.LIRLowerable;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
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;

import jdk.vm.ci.meta.JavaKind;

A node that changes the type of its input, usually narrowing it. For example, a GuardedValueNode is used to keep the nodes depending on guards inside a loop during speculative guard movement. A GuardedValueNode will only go away if its guard is null or StructuredGraph.start().
/** * A node that changes the type of its input, usually narrowing it. For example, a GuardedValueNode * is used to keep the nodes depending on guards inside a loop during speculative guard movement. * * A GuardedValueNode will only go away if its guard is null or {@link StructuredGraph#start()}. */
@NodeInfo(cycles = CYCLES_0, size = SIZE_0) public final class GuardedValueNode extends FloatingGuardedNode implements LIRLowerable, Virtualizable, IterableNodeType, Canonicalizable, ValueProxy { public static final NodeClass<GuardedValueNode> TYPE = NodeClass.create(GuardedValueNode.class); @Input ValueNode object; protected final Stamp piStamp; public GuardedValueNode(ValueNode object, GuardingNode guard, Stamp stamp) { super(TYPE, computeStamp(stamp, object), guard); this.object = object; this.piStamp = stamp; } public GuardedValueNode(ValueNode object, GuardingNode guard) { this(object, guard, object.stamp()); } public ValueNode object() { return object; } @Override public void generate(NodeLIRBuilderTool generator) { if (object.getStackKind() != JavaKind.Void && object.getStackKind() != JavaKind.Illegal) { generator.setResult(this, generator.operand(object)); } } @Override public boolean inferStamp() { return updateStamp(computeStamp(piStamp, object())); } static Stamp computeStamp(Stamp piStamp, ValueNode object) { return piStamp.improveWith(object.stamp()); } @Override public void virtualize(VirtualizerTool tool) { ValueNode alias = tool.getAlias(object()); if (alias instanceof VirtualObjectNode) { tool.replaceWithVirtual((VirtualObjectNode) alias); } } @Override public Node canonical(CanonicalizerTool tool) { if (getGuard() == null) { if (stamp().equals(object().stamp())) { return object(); } else { return new PiNode(object(), stamp()); } } return this; } @Override public ValueNode getOriginalNode() { return object; } }