src/mem/cache/replacement_policies/ReplacementPolicies.py

# Copyright (c) 2018-2020 Inria
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from m5.params import *
from m5.proxy import *
from m5.SimObject import SimObject


class BaseReplacementPolicy(SimObject):
    type = "BaseReplacementPolicy"
    abstract = True
    cxx_class = "gem5::replacement_policy::Base"
    cxx_header = "mem/cache/replacement_policies/base.hh"


class DuelingRP(BaseReplacementPolicy):
    type = "DuelingRP"
    cxx_class = "gem5::replacement_policy::Dueling"
    cxx_header = "mem/cache/replacement_policies/dueling_rp.hh"

    constituency_size = Param.Unsigned(
        "The size of a region containing one sample"
    )
    team_size = Param.Unsigned(
        "Number of entries in a sampling set that belong to a team"
    )
    replacement_policy_a = Param.BaseReplacementPolicy(
        "Sub-replacement policy A"
    )
    replacement_policy_b = Param.BaseReplacementPolicy(
        "Sub-replacement policy B"
    )


class FIFORP(BaseReplacementPolicy):
    type = "FIFORP"
    cxx_class = "gem5::replacement_policy::FIFO"
    cxx_header = "mem/cache/replacement_policies/fifo_rp.hh"


class SecondChanceRP(FIFORP):
    type = "SecondChanceRP"
    cxx_class = "gem5::replacement_policy::SecondChance"
    cxx_header = "mem/cache/replacement_policies/second_chance_rp.hh"


class LFURP(BaseReplacementPolicy):
    type = "LFURP"
    cxx_class = "gem5::replacement_policy::LFU"
    cxx_header = "mem/cache/replacement_policies/lfu_rp.hh"


class LRURP(BaseReplacementPolicy):
    type = "LRURP"
    cxx_class = "gem5::replacement_policy::LRU"
    cxx_header = "mem/cache/replacement_policies/lru_rp.hh"


class BIPRP(LRURP):
    type = "BIPRP"
    cxx_class = "gem5::replacement_policy::BIP"
    cxx_header = "mem/cache/replacement_policies/bip_rp.hh"
    btp = Param.Percent(3, "Percentage of blocks to be inserted as MRU")


class LIPRP(BIPRP):
    btp = 0


class MRURP(BaseReplacementPolicy):
    type = "MRURP"
    cxx_class = "gem5::replacement_policy::MRU"
    cxx_header = "mem/cache/replacement_policies/mru_rp.hh"


class RandomRP(BaseReplacementPolicy):
    type = "RandomRP"
    cxx_class = "gem5::replacement_policy::Random"
    cxx_header = "mem/cache/replacement_policies/random_rp.hh"


class BRRIPRP(BaseReplacementPolicy):
    type = "BRRIPRP"
    cxx_class = "gem5::replacement_policy::BRRIP"
    cxx_header = "mem/cache/replacement_policies/brrip_rp.hh"
    num_bits = Param.Int(2, "Number of bits per RRPV")
    hit_priority = Param.Bool(
        False, "Prioritize evicting blocks that havent had a hit recently"
    )
    btp = Param.Percent(
        3, "Percentage of blocks to be inserted with long RRPV"
    )


class RRIPRP(BRRIPRP):
    btp = 100


class DRRIPRP(DuelingRP):
    # The constituency_size and the team_size must be manually provided, where:
    #     constituency_size = num_cache_entries /
    #         (num_dueling_sets * num_entries_per_set)
    # The paper assumes that:
    #     num_dueling_sets = 32
    #     team_size = num_entries_per_set
    replacement_policy_a = BRRIPRP()
    replacement_policy_b = RRIPRP()


class NRURP(BRRIPRP):
    btp = 100
    num_bits = 1


class SHiPRP(BRRIPRP):
    type = "SHiPRP"
    abstract = True
    cxx_class = "gem5::replacement_policy::SHiP"
    cxx_header = "mem/cache/replacement_policies/ship_rp.hh"

    shct_size = Param.Unsigned(16384, "Number of SHCT entries")
    # By default any value greater than 0 is enough to change insertion policy
    insertion_threshold = Param.Percent(
        1, "Percentage at which an entry changes insertion policy"
    )
    # Always make hits mark entries as last to be evicted
    hit_priority = True
    # Let the predictor decide when to change insertion policy
    btp = 0


class SHiPMemRP(SHiPRP):
    type = "SHiPMemRP"
    cxx_class = "gem5::replacement_policy::SHiPMem"
    cxx_header = "mem/cache/replacement_policies/ship_rp.hh"


class SHiPPCRP(SHiPRP):
    type = "SHiPPCRP"
    cxx_class = "gem5::replacement_policy::SHiPPC"
    cxx_header = "mem/cache/replacement_policies/ship_rp.hh"


class TreePLRURP(BaseReplacementPolicy):
    type = "TreePLRURP"
    cxx_class = "gem5::replacement_policy::TreePLRU"
    cxx_header = "mem/cache/replacement_policies/tree_plru_rp.hh"
    num_leaves = Param.Int(Parent.assoc, "Number of leaves in each tree")


class WeightedLRURP(LRURP):
    type = "WeightedLRURP"
    cxx_class = "gem5::replacement_policy::WeightedLRU"
    cxx_header = "mem/cache/replacement_policies/weighted_lru_rp.hh"