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 * Copyright (c) 2011, 2020, 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 org.graalvm.compiler.nodes.virtual;

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;

import org.graalvm.compiler.core.common.spi.MetaAccessExtensionProvider;
import org.graalvm.compiler.core.common.type.StampFactory;
import org.graalvm.compiler.core.common.type.TypeReference;
import org.graalvm.compiler.graph.IterableNodeType;
import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.FixedNode;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.spi.LIRLowerable;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import org.graalvm.compiler.nodes.spi.VirtualizerTool;

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

@NodeInfo(cycles = CYCLES_0, size = SIZE_0)
public abstract class VirtualObjectNode extends ValueNode implements LIRLowerable, IterableNodeType {

    public static final NodeClass<VirtualObjectNode> TYPE = NodeClass.create(VirtualObjectNode.class);
    protected boolean hasIdentity;
    private int objectId = -1;

    protected VirtualObjectNode(NodeClass<? extends VirtualObjectNode> c, ResolvedJavaType type, boolean hasIdentity) {
        super(c, StampFactory.objectNonNull(TypeReference.createExactTrusted(type)));
        this.hasIdentity = hasIdentity;
    }

    public final int getObjectId() {
        return objectId;
    }

    public final void resetObjectId() {
        this.objectId = -1;
    }

    public final void setObjectId(int objectId) {
        assert objectId != -1;
        this.objectId = objectId;
    }

    @Override
    protected void afterClone(Node other) {
        super.afterClone(other);
        resetObjectId();
    }

    
The type of object described by this VirtualObjectNode. In case of arrays, this is the array type (and not the component type).
/** * The type of object described by this {@link VirtualObjectNode}. In case of arrays, this is * the array type (and not the component type). */
public abstract ResolvedJavaType type();
The number of entries this virtual object has. Either the number of fields or the number of array elements.
/** * The number of entries this virtual object has. Either the number of fields or the number of * array elements. */
public abstract int entryCount();
Returns the name of the entry at the given index. Only used for debugging purposes.
/** * Returns the name of the entry at the given index. Only used for debugging purposes. */
public abstract String entryName(int i);
If the given index denotes an entry in this virtual object, the index of this entry is returned. If no such entry can be found, this method returns -1.
Params:
  • constantOffset – offset, where the value is placed.
  • expectedEntryKind – Specifies which type is expected at this offset (Is important when
/** * If the given index denotes an entry in this virtual object, the index of this entry is * returned. If no such entry can be found, this method returns -1. * * @param constantOffset offset, where the value is placed. * @param expectedEntryKind Specifies which type is expected at this offset (Is important when */
public abstract int entryIndexForOffset(MetaAccessProvider metaAccess, long constantOffset, JavaKind expectedEntryKind);
Returns the JavaKind of the entry at the given index.
/** * Returns the {@link JavaKind} of the entry at the given index. */
public abstract JavaKind entryKind(MetaAccessExtensionProvider metaAccessExtensionProvider, int index);
Returns an exact duplicate of this virtual object node, which has not been added to the graph yet.
/** * Returns an exact duplicate of this virtual object node, which has not been added to the graph * yet. */
public abstract VirtualObjectNode duplicate();
Specifies whether this virtual object has an object identity. If not, then the result of a comparison of two virtual objects is determined by comparing their contents.
/** * Specifies whether this virtual object has an object identity. If not, then the result of a * comparison of two virtual objects is determined by comparing their contents. */
public boolean hasIdentity() { return hasIdentity; } public void setIdentity(boolean identity) { this.hasIdentity = identity; }
Returns a node that can be used to materialize this virtual object. If this returns an AllocatedObjectNode then this node will be attached to a CommitAllocationNode , otherwise the node will just be added to the graph.
/** * Returns a node that can be used to materialize this virtual object. If this returns an * {@link AllocatedObjectNode} then this node will be attached to a {@link CommitAllocationNode} * , otherwise the node will just be added to the graph. */
public abstract ValueNode getMaterializedRepresentation(FixedNode fixed, ValueNode[] entries, LockState locks); @Override public void generate(NodeLIRBuilderTool gen) { // nothing to do... }
Checks that a read in a virtual object is a candidate for byte array virtualization. Virtualizing reads in byte arrays can happen iff all of these hold true:
  • The virtualized object is a virtualized byte array
  • Both the virtualized entry and the access kind are primitives
  • The number of bytes actually occupied by the entry is equal to the number of bytes of the access kind
  • /** * Checks that a read in a virtual object is a candidate for byte array virtualization. * * Virtualizing reads in byte arrays can happen iff all of these hold true: * <li>The virtualized object is a virtualized byte array * <li>Both the virtualized entry and the access kind are primitives * <li>The number of bytes actually occupied by the entry is equal to the number of bytes of the * access kind */
    public boolean canVirtualizeLargeByteArrayUnsafeRead(ValueNode entry, int index, JavaKind accessKind, VirtualizerTool tool) { return (tool.canVirtualizeLargeByteArrayUnsafeAccess() || accessKind == JavaKind.Byte) && !entry.isIllegalConstant() && entry.getStackKind() == accessKind.getStackKind() && isVirtualByteArrayAccess(tool.getMetaAccessExtensionProvider(), accessKind) && accessKind.getByteCount() == ((VirtualArrayNode) this).byteArrayEntryByteCount(index, tool); } public boolean isVirtualByteArrayAccess(MetaAccessExtensionProvider metaAccessExtensionProvider, JavaKind accessKind) { return accessKind.isPrimitive() && isVirtualByteArray(metaAccessExtensionProvider); } public boolean isVirtualByteArray(MetaAccessExtensionProvider metaAccessExtensionProvider) { return isVirtualArray() && entryCount() > 0 && entryKind(metaAccessExtensionProvider, 0) == JavaKind.Byte; } private boolean isVirtualArray() { return this instanceof VirtualArrayNode; } }