001/*
002 * Copyright (c) 2009, 2014, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.nodes.calc;
024
025import jdk.internal.jvmci.meta.*;
026
027import com.oracle.graal.compiler.common.calc.*;
028import com.oracle.graal.compiler.common.type.*;
029import com.oracle.graal.graph.*;
030import com.oracle.graal.graph.spi.*;
031import com.oracle.graal.nodeinfo.*;
032import com.oracle.graal.nodes.*;
033import com.oracle.graal.nodes.spi.*;
034
035/**
036 * Returns -1, 0, or 1 if either x < y, x == y, or x > y. If the comparison is undecided (one
037 * of the inputs is NaN), the result is 1 if isUnorderedLess is false and -1 if isUnorderedLess is
038 * true.
039 */
040@NodeInfo
041public final class NormalizeCompareNode extends BinaryNode implements Lowerable {
042
043    public static final NodeClass<NormalizeCompareNode> TYPE = NodeClass.create(NormalizeCompareNode.class);
044    protected final boolean isUnorderedLess;
045
046    public NormalizeCompareNode(ValueNode x, ValueNode y, boolean isUnorderedLess) {
047        super(TYPE, StampFactory.forKind(Kind.Int), x, y);
048        this.isUnorderedLess = isUnorderedLess;
049    }
050
051    public static ValueNode create(ValueNode x, ValueNode y, boolean isUnorderedLess, ConstantReflectionProvider constantReflection) {
052        LogicNode result = CompareNode.tryConstantFold(Condition.EQ, x, y, constantReflection, false);
053        if (result instanceof LogicConstantNode) {
054            LogicConstantNode logicConstantNode = (LogicConstantNode) result;
055            LogicNode resultLT = CompareNode.tryConstantFold(Condition.LT, x, y, constantReflection, isUnorderedLess);
056            if (resultLT instanceof LogicConstantNode) {
057                LogicConstantNode logicConstantNodeLT = (LogicConstantNode) resultLT;
058                if (logicConstantNodeLT.getValue()) {
059                    return ConstantNode.forInt(-1);
060                } else if (logicConstantNode.getValue()) {
061                    return ConstantNode.forInt(0);
062                } else {
063                    return ConstantNode.forInt(1);
064                }
065            }
066        }
067
068        return new NormalizeCompareNode(x, y, isUnorderedLess);
069    }
070
071    @Override
072    public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
073        // nothing to do
074        return this;
075    }
076
077    @Override
078    public void lower(LoweringTool tool) {
079        LogicNode equalComp;
080        LogicNode lessComp;
081        if (getX().stamp() instanceof FloatStamp) {
082            equalComp = graph().unique(FloatEqualsNode.create(getX(), getY(), tool.getConstantReflection()));
083            lessComp = graph().unique(FloatLessThanNode.create(getX(), getY(), isUnorderedLess, tool.getConstantReflection()));
084        } else {
085            equalComp = graph().unique(IntegerEqualsNode.create(getX(), getY(), tool.getConstantReflection()));
086            lessComp = graph().unique(IntegerLessThanNode.create(getX(), getY(), tool.getConstantReflection()));
087        }
088
089        ConditionalNode equalValue = graph().unique(new ConditionalNode(equalComp, ConstantNode.forInt(0, graph()), ConstantNode.forInt(1, graph())));
090        ConditionalNode value = graph().unique(new ConditionalNode(lessComp, ConstantNode.forInt(-1, graph()), equalValue));
091
092        graph().replaceFloating(this, value);
093    }
094}