/*

 * Copyright (c) 2014, 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 java.io.Serializable;

import java.util.function.Function;

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

import org.graalvm.compiler.core.common.type.ArithmeticOpTable.IntegerConvertOp;

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

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.CanonicalizerTool;

import org.graalvm.compiler.nodeinfo.NodeInfo;

import org.graalvm.compiler.nodes.ArithmeticOperation;

import org.graalvm.compiler.nodes.ConstantNode;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.ValueNode;

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

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

import jdk.vm.ci.meta.Constant;

import jdk.vm.ci.meta.ConstantReflectionProvider;

/**

 * An {@code IntegerConvert} converts an integer to an integer of different width.

 */

@NodeInfo

public abstract class IntegerConvertNode<OP, REV> extends UnaryNode implements ArithmeticOperation, ConvertNode, ArithmeticLIRLowerable, StampInverter {

    @SuppressWarnings("rawtypes") public static final NodeClass<IntegerConvertNode> TYPE = NodeClass.create(IntegerConvertNode.class);

    protected final SerializableIntegerConvertFunction<OP> getOp;

    protected final SerializableIntegerConvertFunction<REV> getReverseOp;

    protected final int inputBits;

    protected final int resultBits;

    protected interface SerializableIntegerConvertFunction<T> extends Function<ArithmeticOpTable, IntegerConvertOp<T>>, Serializable {

    }

    protected IntegerConvertNode(NodeClass<? extends IntegerConvertNode<OP, REV>> c, SerializableIntegerConvertFunction<OP> getOp, SerializableIntegerConvertFunction<REV> getReverseOp, int inputBits,

                    int resultBits, ValueNode input) {

        super(c, getOp.apply(ArithmeticOpTable.forStamp(input.stamp())).foldStamp(inputBits, resultBits, input.stamp()), input);

        this.getOp = getOp;

        this.getReverseOp = getReverseOp;

        this.inputBits = inputBits;

        this.resultBits = resultBits;

        assert ((PrimitiveStamp) input.stamp()).getBits() == inputBits;

    }

    public int getInputBits() {

        return inputBits;

    }

    public int getResultBits() {

        return resultBits;

    }

    protected final IntegerConvertOp<OP> getOp(ValueNode forValue) {

        return getOp.apply(ArithmeticOpTable.forStamp(forValue.stamp()));

    }

    @Override

    public final IntegerConvertOp<OP> getArithmeticOp() {

        return getOp(getValue());

    }

    @Override

    public Constant convert(Constant c, ConstantReflectionProvider constantReflection) {

        return getArithmeticOp().foldConstant(getInputBits(), getResultBits(), c);

    }

    @Override

    public Constant reverse(Constant c, ConstantReflectionProvider constantReflection) {

        IntegerConvertOp<REV> reverse = getReverseOp.apply(ArithmeticOpTable.forStamp(stamp()));

        return reverse.foldConstant(getResultBits(), getInputBits(), c);

    }

    @Override

    public Stamp foldStamp(Stamp newStamp) {

        assert newStamp.isCompatible(getValue().stamp());

        return getArithmeticOp().foldStamp(inputBits, resultBits, newStamp);

    }

    @Override

    public ValueNode canonical(CanonicalizerTool tool, ValueNode forValue) {

        ValueNode synonym = findSynonym(getOp(forValue), forValue, inputBits, resultBits, stamp());

        if (synonym != null) {

            return synonym;

        }

        return this;

    }

    protected static <T> ValueNode findSynonym(IntegerConvertOp<T> operation, ValueNode value, int inputBits, int resultBits, Stamp stamp) {

        if (inputBits == resultBits) {

            return value;

        } else if (value.isConstant()) {

            return ConstantNode.forPrimitive(stamp, operation.foldConstant(inputBits, resultBits, value.asConstant()));

        }

        return null;

    }

    public static ValueNode convert(ValueNode input, Stamp stamp) {

        return convert(input, stamp, false);

    }

    public static ValueNode convert(ValueNode input, Stamp stamp, StructuredGraph graph) {

        ValueNode convert = convert(input, stamp, false);

        if (!convert.isAlive()) {

            assert !convert.isDeleted();

        }

        return convert;

    }

    public static ValueNode convertUnsigned(ValueNode input, Stamp stamp) {

        return convert(input, stamp, true);

    }

    public static ValueNode convert(ValueNode input, Stamp stamp, boolean zeroExtend) {

        IntegerStamp fromStamp = (IntegerStamp) input.stamp();

        IntegerStamp toStamp = (IntegerStamp) stamp;

        ValueNode result;

        if (toStamp.getBits() == fromStamp.getBits()) {

            result = input;

        } else if (toStamp.getBits() < fromStamp.getBits()) {

            result = new NarrowNode(input, fromStamp.getBits(), toStamp.getBits());

        } else if (zeroExtend) {

            // toStamp.getBits() > fromStamp.getBits()

            result = ZeroExtendNode.create(input, toStamp.getBits());

        } else {

            // toStamp.getBits() > fromStamp.getBits()

            result = SignExtendNode.create(input, toStamp.getBits());

        }

        IntegerStamp resultStamp = (IntegerStamp) result.stamp();

        assert toStamp.getBits() == resultStamp.getBits();

        return result;

    }

    @Override

    public Stamp invertStamp(Stamp outStamp) {

        return getArithmeticOp().invertStamp(inputBits, resultBits, outStamp);

    }

}