src/mem/cache/replacement_policies/weighted_lru_rp.hh

/*
 * Copyright (c) 2013-2015 Advanced Micro Devices, Inc.
 * All rights reserved.
 *
 * For use for simulation and test purposes only
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 3. Neither the name of the copyright holder 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 LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_WEIGHTED_LRU_RP_HH__
#define __MEM_CACHE_REPLACEMENT_POLICIES_WEIGHTED_LRU_RP_HH__

#include <memory>

#include "base/types.hh"
#include "mem/cache/replacement_policies/lru_rp.hh"

namespace gem5
{

struct WeightedLRURPParams;

GEM5_DEPRECATED_NAMESPACE(ReplacementPolicy, replacement_policy);
namespace replacement_policy
{

class WeightedLRU : public LRU
{
  protected:
    /** Weighted LRU implementation of replacement data. */
    struct WeightedLRUReplData : LRUReplData
    {
        /** pointer for last occupancy */
        int last_occ_ptr;

        /**
         * Default constructor. Invalidate data.
         */
        WeightedLRUReplData() : LRUReplData(), last_occ_ptr(0) {}
    };
  public:
    typedef WeightedLRURPParams Params;
    WeightedLRU(const Params &p);
    ~WeightedLRU() = default;

    using Base::touch;
    void touch(const std::shared_ptr<ReplacementData>& replacement_data,
                                        int occupancy) const;

    /**
     * Instantiate a replacement data entry.
     *
     * @return A shared pointer to the new replacement data.
     */
    std::shared_ptr<ReplacementData> instantiateEntry() override;

    /**
     * Find replacement victim using weight.
     *
     * @param candidates Replacement candidates, selected by indexing policy.
     * @return Replacement entry to be replaced.
     */
    ReplaceableEntry* getVictim(const ReplacementCandidates&
                                              candidates) const override;
};

} // namespace replacement_policy
} // namespace gem5

#endif // __MEM_CACHE_REPLACEMENT_POLICIES_WEIGHTED_LRU_RP_HH__