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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 * 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.
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 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package org.graalvm.compiler.nodes.calc;

import org.graalvm.compiler.core.common.type.ArithmeticOpTable;
import org.graalvm.compiler.core.common.type.ArithmeticOpTable.BinaryOp;
import org.graalvm.compiler.core.common.type.ArithmeticOpTable.BinaryOp.Xor;
import org.graalvm.compiler.core.common.type.PrimitiveStamp;
import org.graalvm.compiler.core.common.type.Stamp;
import org.graalvm.compiler.graph.NodeClass;
import org.graalvm.compiler.graph.spi.Canonicalizable.BinaryCommutative;
import org.graalvm.compiler.graph.spi.CanonicalizerTool;
import org.graalvm.compiler.lir.gen.ArithmeticLIRGeneratorTool;
import org.graalvm.compiler.nodeinfo.NodeInfo;
import org.graalvm.compiler.nodes.ConstantNode;
import org.graalvm.compiler.nodes.NodeView;
import org.graalvm.compiler.nodes.ValueNode;
import org.graalvm.compiler.nodes.spi.NodeLIRBuilderTool;
import org.graalvm.compiler.nodes.util.GraphUtil;

import jdk.vm.ci.code.CodeUtil;
import jdk.vm.ci.meta.Constant;
import jdk.vm.ci.meta.PrimitiveConstant;

@NodeInfo(shortName = "^")
public final class XorNode extends BinaryArithmeticNode<Xor> implements BinaryCommutative<ValueNode>, NarrowableArithmeticNode {

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

    public XorNode(ValueNode x, ValueNode y) {
        super(TYPE, getArithmeticOpTable(x).getXor(), x, y);
        assert x.stamp(NodeView.DEFAULT).isCompatible(y.stamp(NodeView.DEFAULT));
    }

    private XorNode(ValueNode x, ValueNode y, Stamp forcedStamp) {
        super(TYPE, forcedStamp, x, y);
    }

    /**
     * Create a new XorNode with a forced stamp, without eager folding. This should only be used in
     * snippet code, where native-image may assign wrong stamps during graph generation.
     */
    public static ValueNode createForSnippet(ValueNode x, ValueNode y, Stamp forcedStamp) {
        return new XorNode(x, y, forcedStamp);
    }

    public static ValueNode create(ValueNode x, ValueNode y, NodeView view) {
        BinaryOp<Xor> op = ArithmeticOpTable.forStamp(x.stamp(view)).getXor();
        Stamp stamp = op.foldStamp(x.stamp(view), y.stamp(view));
        ConstantNode tryConstantFold = tryConstantFold(op, x, y, stamp, view);
        if (tryConstantFold != null) {
            return tryConstantFold;
        }
        return canonical(null, op, stamp, x, y, view);
    }

    @Override
    protected BinaryOp<Xor> getOp(ArithmeticOpTable table) {
        return table.getXor();
    }

    @Override
    public ValueNode canonical(CanonicalizerTool tool, ValueNode forX, ValueNode forY) {
        ValueNode ret = super.canonical(tool, forX, forY);
        if (ret != this) {
            return ret;
        }

        NodeView view = NodeView.from(tool);
        return canonical(this, getOp(forX, forY), stamp(NodeView.DEFAULT), forX, forY, view);
    }

    private static ValueNode canonical(XorNode self, BinaryOp<Xor> op, Stamp stamp, ValueNode forX, ValueNode forY, NodeView view) {
        if (GraphUtil.unproxify(forX) == GraphUtil.unproxify(forY)) {
            return ConstantNode.forPrimitive(stamp, op.getZero(forX.stamp(view)));
        }
        if (forX.isConstant() && !forY.isConstant()) {
            return new XorNode(forY, forX);
        }
        if (forY.isConstant()) {
            Constant c = forY.asConstant();
            if (op.isNeutral(c)) {
                return forX;
            }

            if (c instanceof PrimitiveConstant && ((PrimitiveConstant) c).getJavaKind().isNumericInteger()) {
                long rawY = ((PrimitiveConstant) c).asLong();
                long mask = CodeUtil.mask(PrimitiveStamp.getBits(stamp));
                if ((rawY & mask) == mask) {
                    return new NotNode(forX);
                }
            }
            return reassociate(self != null ? self : (XorNode) new XorNode(forX, forY).maybeCommuteInputs(), ValueNode.isConstantPredicate(), forX, forY, view);
        }
        return self != null ? self : new XorNode(forX, forY).maybeCommuteInputs();
    }

    @Override
    public void generate(NodeLIRBuilderTool nodeValueMap, ArithmeticLIRGeneratorTool gen) {
        nodeValueMap.setResult(this, gen.emitXor(nodeValueMap.operand(getX()), nodeValueMap.operand(getY())));
    }
}