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/**
* Copyright (c) 2018 Inria
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* 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
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/**
* @file
* Declaration of a Bimodal Interval Prediction replacement policy.
* Has a probability of when placing new entries, placing them as MRU.
*
* Although both LRU and LIP can be seen as specific cases of BIP
* where the bimodal throtle parameter are 1 and 0, respectively, we
* decide not to inherit from it, and do the other way around (inherit
* from LRU) for efficiency reasons.
*
* In the original paper they use btp = 1/32 ~= 3%.
*/
#ifndef __MEM_CACHE_REPLACEMENT_POLICIES_BIP_RP_HH__
#define __MEM_CACHE_REPLACEMENT_POLICIES_BIP_RP_HH__
#include "mem/cache/replacement_policies/lru_rp.hh"
struct BIPRPParams;
class BIPRP : public LRURP
{
protected:
/**
* Bimodal throtle parameter. Value in the range [0,100] used to decide
* if a new entry is inserted at the MRU or LRU position.
*/
const unsigned btp;
public:
/** Convenience typedef. */
typedef BIPRPParams Params;
/**
* Construct and initiliaze this replacement policy.
*/
BIPRP(const Params *p);
/**
* Destructor.
*/
~BIPRP() {}
/**
* Reset replacement data for an entry. Used when an entry is inserted.
* Uses the bimodal throtle parameter to decide whether the new entry
* should be inserted as MRU, or LRU.
*
* @param replacement_data Replacement data to be reset.
*/
void reset(const std::shared_ptr<ReplacementData>& replacement_data) const
override;
};
#endif // __MEM_CACHE_REPLACEMENT_POLICIES_BIP_RP_HH__