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

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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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package org.graalvm.compiler.core.amd64;

import jdk.vm.ci.code.Register;

import org.graalvm.compiler.asm.amd64.AMD64Address;

import org.graalvm.compiler.core.common.LIRKind;

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

import org.graalvm.compiler.debug.CounterKey;

import org.graalvm.compiler.debug.DebugContext;

import org.graalvm.compiler.graph.NodeClass;

import org.graalvm.compiler.nodeinfo.NodeInfo;

import org.graalvm.compiler.nodes.CompressionNode;

import org.graalvm.compiler.nodes.NodeView;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.ValueNode;

import org.graalvm.compiler.nodes.calc.FloatingNode;

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

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

import static org.graalvm.compiler.nodeinfo.NodeCycles.CYCLES_0;

import static org.graalvm.compiler.nodeinfo.NodeSize.SIZE_0;

public abstract class AMD64CompressAddressLowering extends AMD64AddressLowering {

    private static final CounterKey counterFoldedUncompressDuringAddressLowering = DebugContext.counter("FoldedUncompressDuringAddressLowering");

    @Override

    protected final boolean improve(StructuredGraph graph, DebugContext debug, AMD64AddressNode addr, boolean isBaseNegated, boolean isIndexNegated) {

        if (super.improve(graph, debug, addr, isBaseNegated, isIndexNegated)) {

            return true;

        }

        if (!isBaseNegated && !isIndexNegated && addr.getScale() == AMD64Address.Scale.Times1) {

            ValueNode base = addr.getBase();

            ValueNode index = addr.getIndex();

            if (tryToImproveUncompression(addr, index, base) || tryToImproveUncompression(addr, base, index)) {

                counterFoldedUncompressDuringAddressLowering.increment(debug);

                return true;

            }

        }

        return false;

    }

    private boolean tryToImproveUncompression(AMD64AddressNode addr, ValueNode value, ValueNode other) {

        if (value instanceof CompressionNode) {

            CompressionNode compression = (CompressionNode) value;

            if (compression.getOp() == CompressionNode.CompressionOp.Uncompress && improveUncompression(addr, compression, other)) {

                return true;

            }

        }

        return false;

    }

    protected abstract boolean improveUncompression(AMD64AddressNode addr, CompressionNode compression, ValueNode other);

    @NodeInfo(cycles = CYCLES_0, size = SIZE_0)

    public static class HeapBaseNode extends FloatingNode implements LIRLowerable {

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

        private final Register heapBaseRegister;

        public HeapBaseNode(Register heapBaseRegister) {

            super(TYPE, StampFactory.pointer());

            this.heapBaseRegister = heapBaseRegister;

        }

        @Override

        public void generate(NodeLIRBuilderTool generator) {

            LIRKind kind = generator.getLIRGeneratorTool().getLIRKind(stamp(NodeView.DEFAULT));

            generator.setResult(this, heapBaseRegister.asValue(kind));

        }

    }

}