/*

 * Copyright (c) 2009, 2015, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.graalvm.compiler.nodes.calc;

import org.graalvm.compiler.core.common.calc.Condition;

import org.graalvm.compiler.core.common.type.FloatStamp;

import org.graalvm.compiler.core.common.type.Stamp;

import org.graalvm.compiler.core.common.type.StampFactory;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.graph.spi.CanonicalizerTool;

import org.graalvm.compiler.nodeinfo.NodeCycles;

import org.graalvm.compiler.nodeinfo.NodeInfo;

import org.graalvm.compiler.nodeinfo.NodeSize;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.LogicConstantNode;

import org.graalvm.compiler.nodes.LogicNode;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.spi.Lowerable;

import org.graalvm.compiler.nodes.spi.LoweringTool;

import jdk.vm.ci.meta.ConstantReflectionProvider;

import jdk.vm.ci.meta.JavaKind;

/**

 * Returns -1, 0, or 1 if either x < y, x == y, or x > y. If the comparison is undecided (one

 * of the inputs is NaN), the result is 1 if isUnorderedLess is false and -1 if isUnorderedLess is

 * true.

 */

@NodeInfo(cycles = NodeCycles.CYCLES_2, size = NodeSize.SIZE_4)

public final class NormalizeCompareNode extends BinaryNode implements Lowerable {

    public static final NodeClass<NormalizeCompareNode> TYPE = NodeClass.create(NormalizeCompareNode.class);

    protected final boolean isUnorderedLess;

    public NormalizeCompareNode(ValueNode x, ValueNode y, boolean isUnorderedLess) {

        super(TYPE, StampFactory.forKind(JavaKind.Int), x, y);

        this.isUnorderedLess = isUnorderedLess;

    }

    public static ValueNode create(ValueNode x, ValueNode y, boolean isUnorderedLess, ConstantReflectionProvider constantReflection) {

        LogicNode result = CompareNode.tryConstantFold(Condition.EQ, x, y, constantReflection, false);

        if (result instanceof LogicConstantNode) {

            LogicConstantNode logicConstantNode = (LogicConstantNode) result;

            LogicNode resultLT = CompareNode.tryConstantFold(Condition.LT, x, y, constantReflection, isUnorderedLess);

            if (resultLT instanceof LogicConstantNode) {

                LogicConstantNode logicConstantNodeLT = (LogicConstantNode) resultLT;

                if (logicConstantNodeLT.getValue()) {

                    return ConstantNode.forInt(-1);

                } else if (logicConstantNode.getValue()) {

                    return ConstantNode.forInt(0);

                } else {

                    return ConstantNode.forInt(1);

                }

            }

        }

        return new NormalizeCompareNode(x, y, isUnorderedLess);

    }

    @Override

    public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {

        // nothing to do

        return this;

    }

    @Override

    public boolean inferStamp() {

        return false;

    }

    @Override

    public void lower(LoweringTool tool) {

        LogicNode equalComp;

        LogicNode lessComp;

        if (getX().stamp() instanceof FloatStamp) {

            equalComp = graph().unique(FloatEqualsNode.create(getX(), getY(), tool.getConstantReflection()));

            lessComp = graph().unique(FloatLessThanNode.create(getX(), getY(), isUnorderedLess, tool.getConstantReflection()));

        } else {

            equalComp = graph().unique(IntegerEqualsNode.create(getX(), getY(), tool.getConstantReflection()));

            lessComp = graph().unique(IntegerLessThanNode.create(getX(), getY(), tool.getConstantReflection()));

        }

        ConditionalNode equalValue = graph().unique(new ConditionalNode(equalComp, ConstantNode.forInt(0, graph()), ConstantNode.forInt(1, graph())));

        ConditionalNode value = graph().unique(new ConditionalNode(lessComp, ConstantNode.forInt(-1, graph()), equalValue));

        replaceAtUsagesAndDelete(value);

    }

    @Override

    public Stamp foldStamp(Stamp stampX, Stamp stampY) {

        return stamp();

    }

}