1 /*
   2  * Copyright (c) 2009, 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.calc;
  26 
  27 import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_2;
  28 
  29 import org.graalvm.compiler.core.common.calc.CanonicalCondition;
  30 import org.graalvm.compiler.core.common.type.Stamp;
  31 import org.graalvm.compiler.core.common.type.StampFactory;
  32 import org.graalvm.compiler.graph.IterableNodeType;
  33 import org.graalvm.compiler.graph.NodeClass;
  34 import org.graalvm.compiler.graph.spi.CanonicalizerTool;
  35 import org.graalvm.compiler.nodeinfo.NodeCycles;
  36 import org.graalvm.compiler.nodeinfo.NodeInfo;
  37 import org.graalvm.compiler.nodes.ConstantNode;
  38 import org.graalvm.compiler.nodes.LogicConstantNode;
  39 import org.graalvm.compiler.nodes.LogicNode;
  40 import org.graalvm.compiler.nodes.NodeView;
  41 import org.graalvm.compiler.nodes.ValueNode;
  42 
  43 import jdk.vm.ci.meta.ConstantReflectionProvider;
  44 import jdk.vm.ci.meta.JavaKind;
  45 
  46 /**
  47  * Returns -1, 0, or 1 if either x < y, x == y, or x > y. If the comparison is undecided (one
  48  * of the inputs is NaN), the result is 1 if isUnorderedLess is false and -1 if isUnorderedLess is
  49  * true.
  50  */
  51 @NodeInfo(cycles = NodeCycles.CYCLES_2, size = SIZE_2)
  52 public final class NormalizeCompareNode extends BinaryNode implements IterableNodeType {
  53 
  54     public static final NodeClass<NormalizeCompareNode> TYPE = NodeClass.create(NormalizeCompareNode.class);
  55     protected final boolean isUnorderedLess;
  56 
  57     public NormalizeCompareNode(ValueNode x, ValueNode y, JavaKind kind, boolean isUnorderedLess) {
  58         super(TYPE, StampFactory.forInteger(kind, -1, 1), x, y);
  59         this.isUnorderedLess = isUnorderedLess;
  60     }
  61 
  62     public static ValueNode create(ValueNode x, ValueNode y, boolean isUnorderedLess, JavaKind kind, ConstantReflectionProvider constantReflection) {
  63         ValueNode result = tryConstantFold(x, y, isUnorderedLess, kind, constantReflection);
  64         if (result != null) {
  65             return result;
  66         }
  67 
  68         return new NormalizeCompareNode(x, y, kind, isUnorderedLess);
  69     }
  70 
  71     protected static ValueNode tryConstantFold(ValueNode x, ValueNode y, boolean isUnorderedLess, JavaKind kind, ConstantReflectionProvider constantReflection) {
  72         LogicNode result = CompareNode.tryConstantFold(CanonicalCondition.EQ, x, y, null, false);
  73         if (result instanceof LogicConstantNode) {
  74             LogicConstantNode logicConstantNode = (LogicConstantNode) result;
  75             LogicNode resultLT = CompareNode.tryConstantFold(CanonicalCondition.LT, x, y, constantReflection, isUnorderedLess);
  76             if (resultLT instanceof LogicConstantNode) {
  77                 LogicConstantNode logicConstantNodeLT = (LogicConstantNode) resultLT;
  78                 if (logicConstantNodeLT.getValue()) {
  79                     return ConstantNode.forIntegerKind(kind, -1);
  80                 } else if (logicConstantNode.getValue()) {
  81                     return ConstantNode.forIntegerKind(kind, 0);
  82                 } else {
  83                     return ConstantNode.forIntegerKind(kind, 1);
  84                 }
  85             }
  86         }
  87         return null;
  88     }
  89 
  90     @Override
  91     public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
  92         NodeView view = NodeView.from(tool);
  93         ValueNode result = tryConstantFold(x, y, isUnorderedLess, stamp(view).getStackKind(), tool.getConstantReflection());
  94         if (result != null) {
  95             return result;
  96         }
  97         return this;
  98     }
  99 
 100     @Override
 101     public boolean inferStamp() {
 102         return false;
 103     }
 104 
 105     @Override
 106     public Stamp foldStamp(Stamp stampX, Stamp stampY) {
 107         return stamp(NodeView.DEFAULT);
 108     }
 109 
 110     public boolean isUnorderedLess() {
 111         return isUnorderedLess;
 112     }
 113 }