1 /*
   2  * Copyright (c) 2012, 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;
  24 
  25 import org.graalvm.compiler.graph.Node;
  26 import org.graalvm.compiler.graph.NodeClass;
  27 import org.graalvm.compiler.graph.spi.Canonicalizable;
  28 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  29 import org.graalvm.compiler.nodeinfo.NodeInfo;
  30 import org.graalvm.compiler.nodes.spi.ValueProxy;
  31 import org.graalvm.compiler.nodes.spi.Virtualizable;
  32 import org.graalvm.compiler.nodes.spi.VirtualizerTool;
  33 import org.graalvm.compiler.nodes.virtual.VirtualObjectNode;
  34 
  35 @NodeInfo(nameTemplate = "Proxy({i#value})")
  36 public final class ValueProxyNode extends ProxyNode implements Canonicalizable, Virtualizable, ValueProxy {
  37 
  38     public static final NodeClass<ValueProxyNode> TYPE = NodeClass.create(ValueProxyNode.class);
  39     @Input ValueNode value;
  40     private final boolean loopPhiProxy;
  41 
  42     public ValueProxyNode(ValueNode value, LoopExitNode loopExit) {
  43         super(TYPE, value.stamp(), loopExit);
  44         this.value = value;
  45         loopPhiProxy = loopExit.loopBegin().isPhiAtMerge(value);
  46     }
  47 
  48     @Override
  49     public ValueNode value() {
  50         return value;
  51     }
  52 
  53     @Override
  54     public boolean inferStamp() {
  55         return updateStamp(value.stamp());
  56     }
  57 
  58     @Override
  59     public Node canonical(CanonicalizerTool tool) {
  60         ValueNode curValue = value;
  61         if (curValue.isConstant()) {
  62             return curValue;
  63         }
  64         if (loopPhiProxy && !loopExit.loopBegin().isPhiAtMerge(curValue)) {
  65             return curValue;
  66         }
  67         return this;
  68     }
  69 
  70     @Override
  71     public void virtualize(VirtualizerTool tool) {
  72         ValueNode alias = tool.getAlias(value);
  73         if (alias instanceof VirtualObjectNode) {
  74             tool.replaceWithVirtual((VirtualObjectNode) alias);
  75         }
  76     }
  77 
  78     @Override
  79     public ValueNode getOriginalNode() {
  80         return value();
  81     }
  82 }