sbooe.hh

Go to the documentation of this file.

#ifndef __MEM_CACHE_PREFETCH_SBOOE_HH__
#define __MEM_CACHE_PREFETCH_SBOOE_HH__

#include <deque>
#include <unordered_map>
#include <vector>

#include "mem/cache/prefetch/queued.hh"
#include "mem/packet.hh"

struct SBOOEPrefetcherParams;

class SBOOEPrefetcher : public QueuedPrefetcher
{
    private:

        const int latencyBufferSize;
        const int sequentialPrefetchers;

        const unsigned int scoreThreshold;

        std::unordered_map<Addr, Tick> demandAddresses;

        std::deque<Tick> latencyBuffer;

        Tick averageAccessLatency;

        Tick latencyBufferSum;

        struct SandboxEntry {
            Addr line;
            Tick expectedArrivalTick;
            bool valid;

            SandboxEntry()
                : valid(false)
            {}
        };

        struct Sandbox {
            std::vector<SandboxEntry> entries;
            unsigned int sandboxScore;
            unsigned int lateScore;
            unsigned int index;
            const int stride;

            Sandbox(unsigned int max_entries, int _stride)
                : sandboxScore(0), lateScore(0), index(0), stride(_stride)
            {
                entries.resize(max_entries);
            }

            void insert(Addr line, Tick tick);

            unsigned int score() const {
                return (sandboxScore - lateScore);
            }
        };

        std::vector<Sandbox> sandboxes;

        Sandbox * bestSandbox;

        unsigned int accesses;

        bool access(Addr line);

        void notifyFill(const PacketPtr& pkt) override;

    public:
        SBOOEPrefetcher(const SBOOEPrefetcherParams *p);

        void calculatePrefetch(const PrefetchInfo &pfi,
                               std::vector<AddrPriority> &addresses) override;
};

#endif // __MEM_CACHE_PREFETCH_SBOOE_HH__