repeated_qwords.hh

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/*
 * Copyright (c) 2019 Inria
 * All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 * Authors: Daniel Carvalho
 */

#ifndef __MEM_CACHE_COMPRESSORS_REPEATED_QWORDS_HH__
#define __MEM_CACHE_COMPRESSORS_REPEATED_QWORDS_HH__

#include <array>
#include <cstdint>
#include <map>
#include <memory>

#include "mem/cache/compressors/dictionary_compressor.hh"

struct RepeatedQwordsCompressorParams;

class RepeatedQwordsCompressor : public DictionaryCompressor<uint64_t>
{
  protected:
    using DictionaryEntry = DictionaryCompressor<uint64_t>::DictionaryEntry;

    // Forward declaration of all possible patterns
    class PatternX;
    class PatternM;

    typedef enum {
        X, M, NUM_PATTERNS
    } PatternNumber;

    using PatternFactory = Factory<PatternM, PatternX>;

    uint64_t getNumPatterns() const override { return NUM_PATTERNS; }

    std::string
    getName(int number) const override
    {
        static std::map<int, std::string> pattern_names = {
            {X, "X"}, {M, "M"}
        };

        return pattern_names[number];
    };

    std::unique_ptr<Pattern>
    getPattern(const DictionaryEntry& bytes, const DictionaryEntry& dict_bytes,
        const int match_location) const override
    {
        return PatternFactory::getPattern(bytes, dict_bytes, match_location);
    }

    void addToDictionary(DictionaryEntry data) override;

    std::unique_ptr<BaseCacheCompressor::CompressionData> compress(
        const uint64_t* data, Cycles& comp_lat, Cycles& decomp_lat) override;

  public:
    typedef RepeatedQwordsCompressorParams Params;
    RepeatedQwordsCompressor(const Params *p);
    ~RepeatedQwordsCompressor() = default;
};

class RepeatedQwordsCompressor::PatternX
    : public DictionaryCompressor::UncompressedPattern
{
  public:
    PatternX(const DictionaryEntry bytes, const int match_location)
        : UncompressedPattern(X, 0, 0, match_location, bytes)
    {
    }
};

class RepeatedQwordsCompressor::PatternM
    : public DictionaryCompressor::LocatedMaskedPattern<0xFFFFFFFFFFFFFFFF, 0>
{
  public:
    PatternM(const DictionaryEntry bytes, const int match_location)
        : LocatedMaskedPattern<0xFFFFFFFFFFFFFFFF, 0>(M, 1, 0, match_location,
          bytes)
    {
    }
};

#endif //__MEM_CACHE_COMPRESSORS_REPEATED_QWORDS_HH__