1 /*
   2  * Copyright (c) 2014, 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;
  24 
  25 import static org.graalvm.compiler.nodeinfo.InputType.Memory;
  26 import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;
  27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;
  28 
  29 import org.graalvm.compiler.core.common.type.StampFactory;
  30 import org.graalvm.compiler.graph.Node;
  31 import org.graalvm.compiler.graph.NodeClass;
  32 import org.graalvm.compiler.graph.spi.Canonicalizable;
  33 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  34 import org.graalvm.compiler.nodeinfo.NodeInfo;
  35 import org.graalvm.compiler.nodeinfo.StructuralInput.Memory;
  36 import org.graalvm.compiler.nodes.FixedWithNextNode;
  37 import org.graalvm.compiler.nodes.spi.LIRLowerable;
  38 import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
  39 
  40 @NodeInfo(allowedUsageTypes = Memory, cycles = CYCLES_0, size = SIZE_0)
  41 public final class MemoryAnchorNode extends FixedWithNextNode implements LIRLowerable, MemoryNode, Canonicalizable {
  42 
  43     public static final NodeClass<MemoryAnchorNode> TYPE = NodeClass.create(MemoryAnchorNode.class);
  44 
  45     public MemoryAnchorNode() {
  46         super(TYPE, StampFactory.forVoid());
  47     }
  48 
  49     @Override
  50     public void generate(NodeLIRBuilderTool generator) {
  51         // Nothing to emit, since this node is used for structural purposes only.
  52     }
  53 
  54     @Override
  55     public Node canonical(CanonicalizerTool tool) {
  56         return tool.allUsagesAvailable() && hasNoUsages() ? null : this;
  57     }
  58 
  59     @NodeIntrinsic
  60     public static native Memory anchor();
  61 }