1 /*
   2  * Copyright (c) 2011, 2015, 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 package org.graalvm.compiler.nodes.extended;
  24 
  25 import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
  26 
  27 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_2;
  28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  29 
  30 import org.graalvm.compiler.core.common.type.ObjectStamp;
  31 import org.graalvm.compiler.core.common.type.Stamp;
  32 import org.graalvm.compiler.core.common.type.TypeReference;
  33 import org.graalvm.compiler.graph.NodeClass;
  34 import org.graalvm.compiler.graph.spi.Canonicalizable;
  35 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  36 import org.graalvm.compiler.nodeinfo.NodeInfo;
  37 import org.graalvm.compiler.nodes.ConstantNode;
  38 import org.graalvm.compiler.nodes.ValueNode;
  39 import org.graalvm.compiler.nodes.calc.FloatingNode;
  40 import org.graalvm.compiler.nodes.spi.Lowerable;
  41 import org.graalvm.compiler.nodes.spi.LoweringTool;
  42 import org.graalvm.compiler.nodes.spi.StampProvider;
  43 import org.graalvm.compiler.nodes.spi.Virtualizable;
  44 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
  45 import org.graalvm.compiler.nodes.type.StampTool;
  46 
  47 import jdk.vm.ci.meta.ConstantReflectionProvider;
  48 import jdk.vm.ci.meta.MetaAccessProvider;
  49 
  50 /**
  51  * Loads an object's hub. The object is not null-checked by this operation.
  52  */
  53 @NodeInfo(cycles = CYCLES_2, size = SIZE_1)
  54 public final class LoadHubNode extends FloatingNode implements Lowerable, Canonicalizable, Virtualizable {
  55 
  56     public static final NodeClass<LoadHubNode> TYPE = NodeClass.create(LoadHubNode.class);
  57     @Input ValueNode value;
  58 
  59     public ValueNode getValue() {
  60         return value;
  61     }
  62 
  63     private static Stamp hubStamp(StampProvider stampProvider, ValueNode value) {
  64         assert value.stamp() instanceof ObjectStamp;
  65         return stampProvider.createHubStamp(((ObjectStamp) value.stamp()));
  66     }
  67 
  68     public static ValueNode create(ValueNode value, StampProvider stampProvider, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) {
  69         Stamp stamp = hubStamp(stampProvider, value);
  70         ValueNode synonym = findSynonym(value, stamp, metaAccess, constantReflection);
  71         if (synonym != null) {
  72             return synonym;
  73         }
  74         return new LoadHubNode(stamp, value);
  75     }
  76 
  77     public LoadHubNode(@InjectedNodeParameter StampProvider stampProvider, ValueNode value) {
  78         this(hubStamp(stampProvider, value), value);
  79     }
  80 
  81     public LoadHubNode(Stamp stamp, ValueNode value) {
  82         super(TYPE, stamp);
  83         this.value = value;
  84     }
  85 
  86     @Override
  87     public void lower(LoweringTool tool) {
  88         tool.getLowerer().lower(this, tool);
  89     }
  90 
  91     @Override
  92     public ValueNode canonical(CanonicalizerTool tool) {
  93         if (!GeneratePIC.getValue()) {
  94             MetaAccessProvider metaAccess = tool.getMetaAccess();
  95             ValueNode curValue = getValue();
  96             ValueNode newNode = findSynonym(curValue, stamp(), metaAccess, tool.getConstantReflection());
  97             if (newNode != null) {
  98                 return newNode;
  99             }
 100         }
 101         return this;
 102     }
 103 
 104     public static ValueNode findSynonym(ValueNode curValue, Stamp stamp, MetaAccessProvider metaAccess, ConstantReflectionProvider constantReflection) {
 105         if (!GeneratePIC.getValue()) {
 106             TypeReference type = StampTool.typeReferenceOrNull(curValue);
 107             if (type != null && type.isExact()) {
 108                 return ConstantNode.forConstant(stamp, constantReflection.asObjectHub(type.getType()), metaAccess);
 109             }
 110         }
 111         return null;
 112     }
 113 
 114     @Override
 115     public void virtualize(VirtualizerTool tool) {
 116         if (!GeneratePIC.getValue()) {
 117             ValueNode alias = tool.getAlias(getValue());
 118             TypeReference type = StampTool.typeReferenceOrNull(alias);
 119             if (type != null && type.isExact()) {
 120                 tool.replaceWithValue(ConstantNode.forConstant(stamp(), tool.getConstantReflectionProvider().asObjectHub(type.getType()), tool.getMetaAccessProvider(), graph()));
 121             }
 122         }
 123     }
 124 }