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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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,
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package org.graalvm.compiler.nodes.extended;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

import org.graalvm.compiler.core.common.type.Stamp;
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.ConstantNode;
import org.graalvm.compiler.nodes.FixedWithNextNode;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.spi.Lowerable;
import org.graalvm.compiler.nodes.spi.LoweringTool;
import org.graalvm.compiler.nodes.spi.StampProvider;

import jdk.vm.ci.meta.ConstantReflectionProvider;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ResolvedJavaType;

Loads the component hub for of the provided array hub. This is a fixed node because on certain VMs, for example the HotSpot VM, the read is only valid when the provided hub is actually an array hub (and not, e.g., a primitive hub), so this node must not float above a possible type check. Properly guarding this node would be possible too, but it is unlikely that the guard would be more flexible than just fixing the node in the control flow.
/** * Loads the component hub for of the provided array hub. * * This is a fixed node because on certain VMs, for example the HotSpot VM, the read is only valid * when the provided hub is actually an array hub (and not, e.g., a primitive hub), so this node * must not float above a possible type check. Properly guarding this node would be possible too, * but it is unlikely that the guard would be more flexible than just fixing the node in the control * flow. */
@NodeInfo(cycles = CYCLES_2, size = SIZE_1) public final class LoadArrayComponentHubNode extends FixedWithNextNode implements Lowerable, Canonicalizable.Unary<ValueNode> { public static final NodeClass<LoadArrayComponentHubNode> TYPE = NodeClass.create(LoadArrayComponentHubNode.class); private @Input ValueNode value; public static ValueNode create(ValueNode value, StampProvider stampProvider, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) { Stamp stamp = stampProvider.createHubStamp(null); return findSynonym(null, value, stamp, metaAccess, constantReflection); } protected LoadArrayComponentHubNode(Stamp stamp, ValueNode value) { super(TYPE, stamp); this.value = value; } @Override public ValueNode getValue() { return value; } @Override public void lower(LoweringTool tool) { tool.getLowerer().lower(this, tool); } @Override public Node canonical(CanonicalizerTool tool, ValueNode forValue) { return findSynonym(this, forValue, stamp, tool.getMetaAccess(), tool.getConstantReflection()); } private static ValueNode findSynonym(LoadArrayComponentHubNode self, ValueNode forValue, Stamp stamp, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) { if (forValue.isConstant()) { ResolvedJavaType type = constantReflection.asJavaType(forValue.asConstant()); if (type != null) { return ConstantNode.forConstant(stamp, constantReflection.asObjectHub(type.getComponentType()), metaAccess); } } return self != null ? self : new LoadArrayComponentHubNode(stamp, forValue); } }