/*
 * Copyright (c) 2011, 2014, 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.compiler.common.type.*;
import com.oracle.graal.graph.spi.*;
import com.oracle.graal.nodeinfo.*;
import com.oracle.graal.nodes.*;

/**
 * This node will perform a "test" operation on its arguments. Its result is equivalent to the
 * expression "(x &amp; y) == 0", meaning that it will return true if (and only if) no bit is set in
 * both x and y.
 */
@NodeInfo
public class IntegerTestNode extends BinaryOpLogicNode {

    /**
     * Constructs a new Test instruction.
     *
     * @param x the instruction producing the first input to the instruction
     * @param y the instruction that produces the second input to this instruction
     */
    public static IntegerTestNode create(ValueNode x, ValueNode y) {
        return new IntegerTestNode(x, y);
    }

    protected IntegerTestNode(ValueNode x, ValueNode y) {
        super(x, y);
    }

    @Override
    public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
        if (forX.isConstant() && forY.isConstant()) {
            return LogicConstantNode.forBoolean((forX.asJavaConstant().asLong() & forY.asJavaConstant().asLong()) == 0);
        }
        if (getX().stamp() instanceof IntegerStamp && getY().stamp() instanceof IntegerStamp) {
            IntegerStamp xStamp = (IntegerStamp) forX.stamp();
            IntegerStamp yStamp = (IntegerStamp) forY.stamp();
            if ((xStamp.upMask() & yStamp.upMask()) == 0) {
                return LogicConstantNode.tautology();
            } else if ((xStamp.downMask() & yStamp.downMask()) != 0) {
                return LogicConstantNode.contradiction();
            }
        }
        return this;
    }
}
