1 /*

     2  * Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 

    25 package org.graalvm.compiler.nodes.extended;

    26 

    27 import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;

    28 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;

    29 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;

    30 

    31 import org.graalvm.compiler.core.common.type.AbstractPointerStamp;

    32 import org.graalvm.compiler.core.common.type.ObjectStamp;

    33 import org.graalvm.compiler.core.common.type.Stamp;

    34 import org.graalvm.compiler.core.common.type.TypeReference;

    35 import org.graalvm.compiler.graph.NodeClass;

    36 import org.graalvm.compiler.graph.spi.Canonicalizable;

    37 import org.graalvm.compiler.graph.spi.CanonicalizerTool;

    38 import org.graalvm.compiler.nodeinfo.NodeInfo;

    39 import org.graalvm.compiler.nodes.ConstantNode;

    40 import org.graalvm.compiler.nodes.NodeView;

    41 import org.graalvm.compiler.nodes.ValueNode;

    42 import org.graalvm.compiler.nodes.calc.FloatingNode;

    43 import org.graalvm.compiler.nodes.spi.Lowerable;

    44 import org.graalvm.compiler.nodes.spi.LoweringTool;

    45 import org.graalvm.compiler.nodes.spi.StampProvider;

    46 import org.graalvm.compiler.nodes.spi.Virtualizable;

    47 import org.graalvm.compiler.nodes.spi.VirtualizerTool;

    48 import org.graalvm.compiler.nodes.type.StampTool;

    49 

    50 import jdk.vm.ci.meta.ConstantReflectionProvider;

    51 import jdk.vm.ci.meta.MetaAccessProvider;

    52 

    53 /**

    54  * Loads an object's hub, or null if the object is null.

    55  */

    56 @NodeInfo(cycles = CYCLES_2, size = SIZE_1)

    57 public final class LoadHubOrNullNode extends FloatingNode implements Lowerable, Canonicalizable, Virtualizable {

    58 

    59     public static final NodeClass<LoadHubOrNullNode> TYPE = NodeClass.create(LoadHubOrNullNode.class);

    60     @Input ValueNode value;

    61 

    62     public ValueNode getValue() {

    63         return value;

    64     }

    65 

    66     private static AbstractPointerStamp hubStamp(StampProvider stampProvider, ValueNode value) {

    67         assert value.stamp(NodeView.DEFAULT) instanceof ObjectStamp;

    68         return stampProvider.createHubStamp(((ObjectStamp) value.stamp(NodeView.DEFAULT))).asMaybeNull();

    69     }

    70 

    71     public static ValueNode create(ValueNode value, StampProvider stampProvider, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) {

    72         AbstractPointerStamp stamp = hubStamp(stampProvider, value);

    73         return create(value, stamp, metaAccess, constantReflection);

    74     }

    75 

    76     public static ValueNode create(ValueNode value, AbstractPointerStamp stamp, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) {

    77         ValueNode synonym = findSynonym(value, stamp, metaAccess, constantReflection);

    78         if (synonym != null) {

    79             return synonym;

    80         }

    81         return new LoadHubOrNullNode(stamp, value);

    82     }

    83 

    84     public LoadHubOrNullNode(@InjectedNodeParameter StampProvider stampProvider, ValueNode value) {

    85         this(hubStamp(stampProvider, value), value);

    86     }

    87 

    88     public LoadHubOrNullNode(Stamp stamp, ValueNode value) {

    89         super(TYPE, stamp);

    90         this.value = value;

    91     }

    92 

    93     @Override

    94     public void lower(LoweringTool tool) {

    95         tool.getLowerer().lower(this, tool);

    96     }

    97 

    98     @Override

    99     public ValueNode canonical(CanonicalizerTool tool) {

   100         if (!GeneratePIC.getValue(tool.getOptions())) {

   101             NodeView view = NodeView.from(tool);

   102             MetaAccessProvider metaAccess = tool.getMetaAccess();

   103             ValueNode curValue = getValue();

   104             ValueNode newNode = findSynonym(curValue, (AbstractPointerStamp) stamp(view), metaAccess, tool.getConstantReflection());

   105             if (newNode != null) {

   106                 return newNode;

   107             }

   108         }

   109         return this;

   110     }

   111 

   112     public static ValueNode findSynonym(ValueNode curValue, AbstractPointerStamp stamp, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) {

   113         if (StampTool.isPointerNonNull(stamp)) {

   114             return LoadHubNode.create(curValue, stamp.asNonNull(), metaAccess, constantReflection);

   115         }

   116         return null;

   117     }

   118 

   119     @Override

   120     public void virtualize(VirtualizerTool tool) {

   121         if (!GeneratePIC.getValue(tool.getOptions())) {

   122             ValueNode alias = tool.getAlias(getValue());

   123             TypeReference type = StampTool.typeReferenceOrNull(alias);

   124             if (type != null && type.isExact()) {

   125                 tool.replaceWithValue(ConstantNode.forConstant(stamp(NodeView.DEFAULT), tool.getConstantReflection().asObjectHub(type.getType()), tool.getMetaAccess(), graph()));

   126             }

   127         }

   128     }

   129 }