1 /*
   2  * Copyright (c) 2015, 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.memory.address;
  24 
  25 import org.graalvm.compiler.core.common.type.ObjectStamp;
  26 import org.graalvm.compiler.graph.Node;
  27 import org.graalvm.compiler.graph.NodeClass;
  28 import org.graalvm.compiler.graph.spi.Canonicalizable;
  29 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  30 import org.graalvm.compiler.nodeinfo.InputType;
  31 import org.graalvm.compiler.nodeinfo.NodeInfo;
  32 import org.graalvm.compiler.nodes.PiNode;
  33 import org.graalvm.compiler.nodes.ValueNode;
  34 import org.graalvm.compiler.nodes.calc.BinaryArithmeticNode;
  35 import org.graalvm.compiler.nodes.spi.PiPushable;
  36 import org.graalvm.compiler.nodes.type.StampTool;
  37 
  38 import jdk.vm.ci.meta.JavaKind;
  39 import jdk.vm.ci.meta.ResolvedJavaField;
  40 import jdk.vm.ci.meta.ResolvedJavaType;
  41 
  42 /**
  43  * Represents an address that is composed of a base and an offset. The base can be either a
  44  * {@link JavaKind#Object}, a word-sized integer or another pointer. The offset must be a word-sized
  45  * integer.
  46  */
  47 @NodeInfo(allowedUsageTypes = InputType.Association)
  48 public class OffsetAddressNode extends AddressNode implements Canonicalizable, PiPushable {
  49     public static final NodeClass<OffsetAddressNode> TYPE = NodeClass.create(OffsetAddressNode.class);
  50 
  51     @Input ValueNode base;
  52     @Input ValueNode offset;
  53 
  54     public OffsetAddressNode(ValueNode base, ValueNode offset) {
  55         super(TYPE);
  56         this.base = base;
  57         this.offset = offset;
  58     }
  59 
  60     public ValueNode getBase() {
  61         return base;
  62     }
  63 
  64     public void setBase(ValueNode base) {
  65         updateUsages(this.base, base);
  66         this.base = base;
  67     }
  68 
  69     public ValueNode getOffset() {
  70         return offset;
  71     }
  72 
  73     public void setOffset(ValueNode offset) {
  74         updateUsages(this.offset, offset);
  75         this.offset = offset;
  76     }
  77 
  78     @Override
  79     public Node canonical(CanonicalizerTool tool) {
  80         if (base instanceof RawAddressNode) {
  81             // The RawAddressNode is redundant, just directly use its input as base.
  82             return new OffsetAddressNode(((RawAddressNode) base).getAddress(), offset);
  83         } else if (base instanceof OffsetAddressNode) {
  84             // Rewrite (&base[offset1])[offset2] to base[offset1 + offset2].
  85             OffsetAddressNode b = (OffsetAddressNode) base;
  86             return new OffsetAddressNode(b.getBase(), BinaryArithmeticNode.add(b.getOffset(), this.getOffset()));
  87         } else {
  88             return this;
  89         }
  90     }
  91 
  92     @Override
  93     public boolean push(PiNode parent) {
  94         if (!(offset.isConstant() && parent.stamp() instanceof ObjectStamp && parent.object().stamp() instanceof ObjectStamp)) {
  95             return false;
  96         }
  97 
  98         ObjectStamp piStamp = (ObjectStamp) parent.stamp();
  99         ResolvedJavaType receiverType = piStamp.type();
 100         if (receiverType == null) {
 101             return false;
 102         }
 103         ResolvedJavaField field = receiverType.findInstanceFieldWithOffset(offset.asJavaConstant().asLong(), JavaKind.Void);
 104         if (field == null) {
 105             // field was not declared by receiverType
 106             return false;
 107         }
 108 
 109         ObjectStamp valueStamp = (ObjectStamp) parent.object().stamp();
 110         ResolvedJavaType valueType = StampTool.typeOrNull(valueStamp);
 111         if (valueType != null && field.getDeclaringClass().isAssignableFrom(valueType)) {
 112             if (piStamp.nonNull() == valueStamp.nonNull() && piStamp.alwaysNull() == valueStamp.alwaysNull()) {
 113                 replaceFirstInput(parent, parent.object());
 114                 return true;
 115             }
 116         }
 117 
 118         return false;
 119     }
 120 
 121     @NodeIntrinsic
 122     public static native Address address(Object base, long offset);
 123 }