1 /*
   2  * Copyright (c) 2013, 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 static org.graalvm.compiler.nodeinfo.InputType.Condition;
  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.graph.NodeClass;
  30 import org.graalvm.compiler.graph.spi.Canonicalizable;
  31 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  32 import org.graalvm.compiler.nodeinfo.NodeInfo;
  33 
  34 /**
  35  * Logic node that negates its argument.
  36  */
  37 @NodeInfo(cycles = CYCLES_0, size = SIZE_0)
  38 public final class LogicNegationNode extends LogicNode implements Canonicalizable.Unary<LogicNode> {
  39 
  40     public static final NodeClass<LogicNegationNode> TYPE = NodeClass.create(LogicNegationNode.class);
  41     @Input(Condition) LogicNode value;
  42 
  43     public LogicNegationNode(LogicNode value) {
  44         super(TYPE);
  45         this.value = value;
  46     }
  47 
  48     public static LogicNode create(LogicNode value) {
  49         LogicNode synonym = findSynonym(value);
  50         if (synonym != null) {
  51             return synonym;
  52         }
  53         return new LogicNegationNode(value);
  54     }
  55 
  56     private static LogicNode findSynonym(LogicNode value) {
  57         if (value instanceof LogicConstantNode) {
  58             LogicConstantNode logicConstantNode = (LogicConstantNode) value;
  59             return LogicConstantNode.forBoolean(!logicConstantNode.getValue());
  60         } else if (value instanceof LogicNegationNode) {
  61             return ((LogicNegationNode) value).getValue();
  62         }
  63         return null;
  64     }
  65 
  66     @Override
  67     public LogicNode getValue() {
  68         return value;
  69     }
  70 
  71     @Override
  72     public LogicNode canonical(CanonicalizerTool tool, LogicNode forValue) {
  73         LogicNode synonym = findSynonym(forValue);
  74         if (synonym != null) {
  75             return synonym;
  76         }
  77         return this;
  78     }
  79 
  80 }