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 
  24 
  25 package org.graalvm.compiler.nodes.virtual;
  26 
  27 import java.nio.ByteOrder;
  28 
  29 import org.graalvm.compiler.graph.NodeClass;
  30 import org.graalvm.compiler.nodeinfo.NodeInfo;
  31 import org.graalvm.compiler.nodeinfo.Verbosity;
  32 import org.graalvm.compiler.nodes.ConstantNode;
  33 import org.graalvm.compiler.nodes.FixedNode;
  34 import org.graalvm.compiler.nodes.ValueNode;
  35 import org.graalvm.compiler.nodes.spi.ArrayLengthProvider;
  36 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  37 
  38 import jdk.vm.ci.meta.ConstantReflectionProvider;
  39 import jdk.vm.ci.meta.JavaKind;
  40 import jdk.vm.ci.meta.MetaAccessProvider;
  41 import jdk.vm.ci.meta.ResolvedJavaType;
  42 
  43 @NodeInfo(nameTemplate = "VirtualArray({p#objectId}) {p#componentType/s}[{p#length}]")
  44 public class VirtualArrayNode extends VirtualObjectNode implements ArrayLengthProvider {
  45 
  46     public static final NodeClass<VirtualArrayNode> TYPE = NodeClass.create(VirtualArrayNode.class);
  47     protected final ResolvedJavaType componentType;
  48     protected final int length;
  49 
  50     public VirtualArrayNode(ResolvedJavaType componentType, int length) {
  51         this(TYPE, componentType, length);
  52     }
  53 
  54     protected VirtualArrayNode(NodeClass<? extends VirtualObjectNode> c, ResolvedJavaType componentType, int length) {
  55         super(c, componentType.getArrayClass(), true);
  56         this.componentType = componentType;
  57         this.length = length;
  58     }
  59 
  60     @Override
  61     public ResolvedJavaType type() {
  62         return componentType.getArrayClass();
  63     }
  64 
  65     public ResolvedJavaType componentType() {
  66         return componentType;
  67     }
  68 
  69     @Override
  70     public int entryCount() {
  71         return length;
  72     }
  73 
  74     @Override
  75     public void generate(NodeLIRBuilderTool gen) {
  76         // nothing to do...
  77     }
  78 
  79     @Override
  80     public String toString(Verbosity verbosity) {
  81         if (verbosity == Verbosity.Name) {
  82             return super.toString(Verbosity.Name) + "(" + getObjectId() + ") " + componentType.getName() + "[" + length + "]";
  83         } else {
  84             return super.toString(verbosity);
  85         }
  86     }
  87 
  88     @Override
  89     public String entryName(int index) {
  90         return "[" + index + "]";
  91     }
  92 
  93     @Override
  94     public int entryIndexForOffset(MetaAccessProvider metaAccess, long constantOffset, JavaKind expectedEntryKind) {
  95         return entryIndexForOffset(metaAccess, constantOffset, expectedEntryKind, componentType, length);
  96     }
  97 
  98     public static int entryIndexForOffset(MetaAccessProvider metaAccess, long constantOffset, JavaKind expectedEntryKind, ResolvedJavaType componentType, int length) {
  99         int baseOffset = metaAccess.getArrayBaseOffset(componentType.getJavaKind());
 100         int indexScale = metaAccess.getArrayIndexScale(componentType.getJavaKind());
 101 
 102         long offset;
 103         if (ByteOrder.nativeOrder() == ByteOrder.BIG_ENDIAN && componentType.isPrimitive()) {
 104             // On big endian, we expect the value to be correctly aligned in memory
 105             int componentByteCount = componentType.getJavaKind().getByteCount();
 106             offset = constantOffset - (componentByteCount - Math.min(componentByteCount, 4 + expectedEntryKind.getByteCount()));
 107         } else {
 108             offset = constantOffset;
 109         }
 110         long index = offset - baseOffset;
 111         if (index % indexScale != 0) {
 112             return -1;
 113         }
 114         long elementIndex = index / indexScale;
 115         if (elementIndex < 0 || elementIndex >= length) {
 116             return -1;
 117         }
 118         return (int) elementIndex;
 119     }
 120 
 121     @Override
 122     public JavaKind entryKind(int index) {
 123         assert index >= 0 && index < length;
 124         return componentType.getJavaKind();
 125     }
 126 
 127     @Override
 128     public VirtualArrayNode duplicate() {
 129         VirtualArrayNode node = new VirtualArrayNode(componentType, length);
 130         node.setNodeSourcePosition(this.getNodeSourcePosition());
 131         return node;
 132     }
 133 
 134     @Override
 135     public ValueNode getMaterializedRepresentation(FixedNode fixed, ValueNode[] entries, LockState locks) {
 136         AllocatedObjectNode node = new AllocatedObjectNode(this);
 137         node.setNodeSourcePosition(this.getNodeSourcePosition());
 138         return node;
 139     }
 140 
 141     @Override
 142     public ValueNode findLength(FindLengthMode mode, ConstantReflectionProvider constantReflection) {
 143         return ConstantNode.forInt(length);
 144     }
 145 }