/*
 * Copyright (c) 2009, 2012, 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 com.oracle.graal.nodes.calc;

import com.oracle.graal.api.meta.*;
import com.oracle.graal.nodes.*;
import com.oracle.graal.nodes.spi.*;
import com.oracle.graal.nodes.type.*;

/**
 * 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.
 */
public final class NormalizeCompareNode extends BinaryNode implements Lowerable {

    public final boolean isUnorderedLess;

    /**
     * Creates a new compare operation.
     *
     * @param x the first input
     * @param y the second input
     * @param isUnorderedLess true when an unordered floating point comparison is interpreted as
     *            less, false when greater.
     */
    public NormalizeCompareNode(ValueNode x, ValueNode y, boolean isUnorderedLess) {
        super(StampFactory.forKind(Kind.Int), x, y);
        this.isUnorderedLess = isUnorderedLess;
    }

    @Override
    public void lower(LoweringTool tool) {
        LogicNode equalComp;
        LogicNode lessComp;
        if (x().stamp() instanceof FloatStamp) {
            equalComp = graph().unique(new FloatEqualsNode(x(), y()));
            lessComp = graph().unique(new FloatLessThanNode(x(), y(), isUnorderedLess));
        } else {
            equalComp = graph().unique(new IntegerEqualsNode(x(), y()));
            lessComp = graph().unique(new IntegerLessThanNode(x(), y()));
        }

        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));

        graph().replaceFloating(this, value);
    }
}