1 /*
   2  * Copyright (c) 2011, 2016, 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.nodeinfo.NodeCycles.CYCLES_2;
  26 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  27 
  28 import org.graalvm.compiler.core.common.type.PrimitiveStamp;
  29 import org.graalvm.compiler.core.common.type.Stamp;
  30 import org.graalvm.compiler.core.common.type.StampFactory;
  31 import org.graalvm.compiler.graph.Node;
  32 import org.graalvm.compiler.graph.NodeClass;
  33 import org.graalvm.compiler.graph.spi.Canonicalizable;
  34 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  35 import org.graalvm.compiler.nodeinfo.NodeInfo;
  36 import org.graalvm.compiler.nodes.ConstantNode;
  37 import org.graalvm.compiler.nodes.ValueNode;
  38 import org.graalvm.compiler.nodes.calc.ReinterpretNode;
  39 import org.graalvm.compiler.nodes.java.LoadFieldNode;
  40 import org.graalvm.compiler.nodes.spi.Lowerable;
  41 import org.graalvm.compiler.nodes.spi.LoweringTool;
  42 import org.graalvm.compiler.nodes.spi.Virtualizable;
  43 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
  44 import org.graalvm.compiler.nodes.type.StampTool;
  45 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
  46 import org.graalvm.word.LocationIdentity;
  47 
  48 import jdk.vm.ci.meta.Assumptions;
  49 import jdk.vm.ci.meta.Constant;
  50 import jdk.vm.ci.meta.JavaConstant;
  51 import jdk.vm.ci.meta.JavaKind;
  52 import jdk.vm.ci.meta.ResolvedJavaField;
  53 import jdk.vm.ci.meta.ResolvedJavaType;
  54 
  55 /**
  56  * Load of a value from a location specified as an offset relative to an object. No null check is
  57  * performed before the load.
  58  */
  59 @NodeInfo(cycles = CYCLES_2, size = SIZE_1)
  60 public class RawLoadNode extends UnsafeAccessNode implements Lowerable, Virtualizable, Canonicalizable {
  61     public static final NodeClass<RawLoadNode> TYPE = NodeClass.create(RawLoadNode.class);
  62 
  63     /**
  64      * This constructor exists for node intrinsics that need a stamp based on {@code accessKind}.
  65      */
  66     public RawLoadNode(ValueNode object, ValueNode offset, JavaKind accessKind, LocationIdentity locationIdentity) {
  67         this(object, offset, accessKind, locationIdentity, false);
  68     }
  69 
  70     public RawLoadNode(ValueNode object, ValueNode offset, JavaKind accessKind, LocationIdentity locationIdentity, boolean forceAnyLocation) {
  71         super(TYPE, StampFactory.forKind(accessKind.getStackKind()), object, offset, accessKind, locationIdentity, forceAnyLocation);
  72     }
  73 
  74     /**
  75      * This constructor exists for node intrinsics that need a stamp based on the return type of the
  76      * {@link org.graalvm.compiler.graph.Node.NodeIntrinsic} annotated method.
  77      */
  78     public RawLoadNode(@InjectedNodeParameter Stamp stamp, ValueNode object, ValueNode offset, LocationIdentity locationIdentity, JavaKind accessKind) {
  79         super(TYPE, stamp, object, offset, accessKind, locationIdentity, false);
  80     }
  81 
  82     protected RawLoadNode(NodeClass<? extends RawLoadNode> c, ValueNode object, ValueNode offset, JavaKind accessKind, LocationIdentity locationIdentity) {
  83         super(c, StampFactory.forKind(accessKind.getStackKind()), object, offset, accessKind, locationIdentity, false);
  84     }
  85 
  86     @Override
  87     public void lower(LoweringTool tool) {
  88         tool.getLowerer().lower(this, tool);
  89     }
  90 
  91     @Override
  92     public void virtualize(VirtualizerTool tool) {
  93         ValueNode alias = tool.getAlias(object());
  94         if (alias instanceof VirtualObjectNode) {
  95             VirtualObjectNode virtual = (VirtualObjectNode) alias;
  96             ValueNode offsetValue = tool.getAlias(offset());
  97             if (offsetValue.isConstant()) {
  98                 long off = offsetValue.asJavaConstant().asLong();
  99                 int entryIndex = virtual.entryIndexForOffset(off, accessKind());
 100 
 101                 if (entryIndex != -1) {
 102                     ValueNode entry = tool.getEntry(virtual, entryIndex);
 103                     JavaKind entryKind = virtual.entryKind(entryIndex);
 104                     if (entry.getStackKind() == getStackKind() || entryKind == accessKind()) {
 105 
 106                         if (!(entry.stamp().isCompatible(stamp()))) {
 107                             if (entry.stamp() instanceof PrimitiveStamp && stamp instanceof PrimitiveStamp) {
 108                                 PrimitiveStamp p1 = (PrimitiveStamp) stamp;
 109                                 PrimitiveStamp p2 = (PrimitiveStamp) entry.stamp();
 110                                 int width1 = p1.getBits();
 111                                 int width2 = p2.getBits();
 112                                 if (width1 == width2) {
 113                                     Node replacement = new ReinterpretNode(p2, entry);
 114                                     tool.replaceWith((ValueNode) replacement);
 115                                     return;
 116                                 } else {
 117                                     // different bit width
 118                                     return;
 119                                 }
 120                             } else {
 121                                 // cannot reinterpret for arbitrary objects
 122                                 return;
 123                             }
 124                         }
 125                         tool.replaceWith(entry);
 126                     }
 127                 }
 128             }
 129         }
 130     }
 131 
 132     @Override
 133     public Node canonical(CanonicalizerTool tool) {
 134         if (!isAnyLocationForced() && getLocationIdentity().isAny()) {
 135             ValueNode targetObject = object();
 136             if (offset().isConstant() && targetObject.isConstant() && !targetObject.isNullConstant()) {
 137                 ConstantNode objectConstant = (ConstantNode) targetObject;
 138                 ResolvedJavaType type = StampTool.typeOrNull(objectConstant);
 139                 if (type != null && type.isArray()) {
 140                     JavaConstant arrayConstant = objectConstant.asJavaConstant();
 141                     if (arrayConstant != null) {
 142                         int stableDimension = objectConstant.getStableDimension();
 143                         if (stableDimension > 0) {
 144                             long constantOffset = offset().asJavaConstant().asLong();
 145                             Constant constant = stamp().readConstant(tool.getConstantReflection().getMemoryAccessProvider(), arrayConstant, constantOffset);
 146                             boolean isDefaultStable = objectConstant.isDefaultStable();
 147                             if (constant != null && (isDefaultStable || !constant.isDefaultForKind())) {
 148                                 return ConstantNode.forConstant(stamp(), constant, stableDimension - 1, isDefaultStable, tool.getMetaAccess());
 149                             }
 150                         }
 151                     }
 152                 }
 153             }
 154         }
 155         return super.canonical(tool);
 156     }
 157 
 158     @Override
 159     protected ValueNode cloneAsFieldAccess(Assumptions assumptions, ResolvedJavaField field) {
 160         return LoadFieldNode.create(assumptions, object(), field);
 161     }
 162 
 163     @Override
 164     protected ValueNode cloneAsArrayAccess(ValueNode location, LocationIdentity identity) {
 165         return new RawLoadNode(object(), location, accessKind(), identity);
 166     }
 167 
 168     @NodeIntrinsic
 169     public static native Object load(Object object, long offset, @ConstantNodeParameter JavaKind kind, @ConstantNodeParameter LocationIdentity locationIdentity);
 170 }
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