NormalizeCompareNode.java revision 12651:6ef01bd40ce2 
1/*
2 * Copyright (c) 2009, 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 */
23package org.graalvm.compiler.nodes.calc;
24
25import org.graalvm.compiler.core.common.calc.Condition;
26import org.graalvm.compiler.core.common.type.FloatStamp;
27import org.graalvm.compiler.core.common.type.Stamp;
28import org.graalvm.compiler.core.common.type.StampFactory;
29import org.graalvm.compiler.graph.NodeClass;
30import org.graalvm.compiler.graph.spi.CanonicalizerTool;
31import org.graalvm.compiler.nodeinfo.NodeCycles;
32import org.graalvm.compiler.nodeinfo.NodeInfo;
33import org.graalvm.compiler.nodeinfo.NodeSize;
34import org.graalvm.compiler.nodes.ConstantNode;
35import org.graalvm.compiler.nodes.LogicConstantNode;
36import org.graalvm.compiler.nodes.LogicNode;
37import org.graalvm.compiler.nodes.ValueNode;
38import org.graalvm.compiler.nodes.spi.Lowerable;
39import org.graalvm.compiler.nodes.spi.LoweringTool;
40
41import jdk.vm.ci.meta.ConstantReflectionProvider;
42import jdk.vm.ci.meta.JavaKind;
43
44/**
45 * Returns -1, 0, or 1 if either x < y, x == y, or x > y. If the comparison is undecided (one
46 * of the inputs is NaN), the result is 1 if isUnorderedLess is false and -1 if isUnorderedLess is
47 * true.
48 */
49@NodeInfo(cycles = NodeCycles.CYCLES_2, size = NodeSize.SIZE_4)
50public final class NormalizeCompareNode extends BinaryNode implements Lowerable {
51
52    public static final NodeClass<NormalizeCompareNode> TYPE = NodeClass.create(NormalizeCompareNode.class);
53    protected final boolean isUnorderedLess;
54
55    public NormalizeCompareNode(ValueNode x, ValueNode y, boolean isUnorderedLess) {
56        super(TYPE, StampFactory.forKind(JavaKind.Int), x, y);
57        this.isUnorderedLess = isUnorderedLess;
58    }
59
60    public static ValueNode create(ValueNode x, ValueNode y, boolean isUnorderedLess, ConstantReflectionProvider constantReflection) {
61        LogicNode result = CompareNode.tryConstantFold(Condition.EQ, x, y, constantReflection, false);
62        if (result instanceof LogicConstantNode) {
63            LogicConstantNode logicConstantNode = (LogicConstantNode) result;
64            LogicNode resultLT = CompareNode.tryConstantFold(Condition.LT, x, y, constantReflection, isUnorderedLess);
65            if (resultLT instanceof LogicConstantNode) {
66                LogicConstantNode logicConstantNodeLT = (LogicConstantNode) resultLT;
67                if (logicConstantNodeLT.getValue()) {
68                    return ConstantNode.forInt(-1);
69                } else if (logicConstantNode.getValue()) {
70                    return ConstantNode.forInt(0);
71                } else {
72                    return ConstantNode.forInt(1);
73                }
74            }
75        }
76
77        return new NormalizeCompareNode(x, y, isUnorderedLess);
78    }
79
80    @Override
81    public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
82        // nothing to do
83        return this;
84    }
85
86    @Override
87    public boolean inferStamp() {
88        return false;
89    }
90
91    @Override
92    public void lower(LoweringTool tool) {
93        LogicNode equalComp;
94        LogicNode lessComp;
95        if (getX().stamp() instanceof FloatStamp) {
96            equalComp = graph().unique(FloatEqualsNode.create(getX(), getY(), tool.getConstantReflection()));
97            lessComp = graph().unique(FloatLessThanNode.create(getX(), getY(), isUnorderedLess, tool.getConstantReflection()));
98        } else {
99            equalComp = graph().unique(IntegerEqualsNode.create(getX(), getY(), tool.getConstantReflection()));
100            lessComp = graph().unique(IntegerLessThanNode.create(getX(), getY(), tool.getConstantReflection()));
101        }
102
103        ConditionalNode equalValue = graph().unique(new ConditionalNode(equalComp, ConstantNode.forInt(0, graph()), ConstantNode.forInt(1, graph())));
104        ConditionalNode value = graph().unique(new ConditionalNode(lessComp, ConstantNode.forInt(-1, graph()), equalValue));
105        replaceAtUsagesAndDelete(value);
106    }
107
108    @Override
109    public Stamp foldStamp(Stamp stampX, Stamp stampY) {
110        return stamp();
111    }
112}
113