zero.hh

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#ifndef __MEM_CACHE_COMPRESSORS_ZERO_HH__
#define __MEM_CACHE_COMPRESSORS_ZERO_HH__
 
#include <array>
#include <cstdint>
#include <map>
#include <memory>
 
#include "mem/cache/compressors/dictionary_compressor.hh"
 
namespace gem5
{
 
struct ZeroCompressorParams;
 
namespace compression
{
 
class Zero : public DictionaryCompressor<uint64_t>
{
  protected:
    using DictionaryEntry = DictionaryCompressor<uint64_t>::DictionaryEntry;
 
    // Forward declaration of all possible patterns
    class PatternX;
    class PatternZ;
 
    enum PatternNumber
    {
        X, Z, NUM_PATTERNS
    };
 
    using PatternFactory = Factory<PatternZ, 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"}, {Z, "Z"}
        };
 
        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<Base::CompressionData> compress(
        const std::vector<Base::Chunk>& chunks,
        Cycles& comp_lat, Cycles& decomp_lat) override;
 
  public:
    typedef ZeroCompressorParams Params;
    Zero(const Params &p);
    ~Zero() = default;
};
 
class Zero::PatternX
    : public DictionaryCompressor::UncompressedPattern
{
  public:
    PatternX(const DictionaryEntry bytes, const int match_location)
        : DictionaryCompressor::UncompressedPattern(X, 0, 0, match_location,
          bytes)
    {
    }
};
 
class Zero::PatternZ
    : public DictionaryCompressor::MaskedValuePattern<0, 0xFFFFFFFFFFFFFFFF>
{
  public:
    PatternZ(const DictionaryEntry bytes, const int match_location)
        : DictionaryCompressor::MaskedValuePattern<0, 0xFFFFFFFFFFFFFFFF>(
          Z, 1, 0, match_location, bytes)
    {
    }
};
 
} // namespace compression
} // namespace gem5
 
#endif //__MEM_CACHE_COMPRESSORS_ZERO_HH__