1 /*
   2  * Copyright (c) 2014, 2018, 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.nodeinfo.NodeCycles.CYCLES_2;
  28 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_1;
  29 
  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.memory.FixedAccessNode;
  37 import org.graalvm.compiler.nodes.memory.ReadNode;
  38 import org.graalvm.compiler.nodes.memory.address.AddressNode;
  39 import org.graalvm.compiler.nodes.spi.Lowerable;
  40 import org.graalvm.compiler.nodes.spi.LoweringTool;
  41 import jdk.internal.vm.compiler.word.LocationIdentity;
  42 
  43 import jdk.vm.ci.meta.JavaKind;
  44 
  45 /**
  46  * Read a raw memory location according to Java field or array read semantics. It will perform read
  47  * barriers, implicit conversions and optionally oop uncompression.
  48  */
  49 @NodeInfo(nameTemplate = "JavaRead#{p#location/s}", cycles = CYCLES_2, size = SIZE_1)
  50 public final class JavaReadNode extends FixedAccessNode implements Lowerable, GuardingNode, Canonicalizable {
  51 
  52     public static final NodeClass<JavaReadNode> TYPE = NodeClass.create(JavaReadNode.class);
  53     protected final JavaKind readKind;
  54     protected final boolean compressible;
  55 
  56     public JavaReadNode(JavaKind readKind, AddressNode address, LocationIdentity location, BarrierType barrierType, boolean compressible) {
  57         super(TYPE, address, location, StampFactory.forKind(readKind), barrierType);
  58         this.readKind = readKind;
  59         this.compressible = compressible;
  60     }
  61 
  62     @Override
  63     public void lower(LoweringTool tool) {
  64         tool.getLowerer().lower(this, tool);
  65     }
  66 
  67     @Override
  68     public boolean canNullCheck() {
  69         return true;
  70     }
  71 
  72     public JavaKind getReadKind() {
  73         return readKind;
  74     }
  75 
  76     public boolean isCompressible() {
  77         return compressible;
  78     }
  79 
  80     @Override
  81     public Node canonical(CanonicalizerTool tool) {
  82         return ReadNode.canonicalizeRead(this, getAddress(), getLocationIdentity(), tool);
  83     }
  84 }