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from m5.defines import buildEnv
from m5.params import *
from m5.proxy import *

from m5.objects.BaseCPU import BaseCPU
from m5.objects.FUPool import *

# from m5.objects.O3Checker import O3Checker
from m5.objects.BranchPredictor import *


class SMTFetchPolicy(ScopedEnum):
    vals = ["RoundRobin", "Branch", "IQCount", "LSQCount"]


class SMTQueuePolicy(ScopedEnum):
    vals = ["Dynamic", "Partitioned", "Threshold"]


class CommitPolicy(ScopedEnum):
    vals = ["RoundRobin", "OldestReady"]


class BaseO3CPU(BaseCPU):
    type = "BaseO3CPU"
    cxx_class = "gem5::o3::CPU"
    cxx_header = "cpu/o3/dyn_inst.hh"

    @classmethod
    def memory_mode(cls):
        return "timing"

    @classmethod
    def require_caches(cls):
        return True

    @classmethod
    def support_take_over(cls):
        return True

    activity = Param.Unsigned(0, "Initial count")

    cacheStorePorts = Param.Unsigned(
        200, "Cache Ports. Constrains stores only."
    )
    cacheLoadPorts = Param.Unsigned(200, "Cache Ports. Constrains loads only.")

    decodeToFetchDelay = Param.Cycles(1, "Decode to fetch delay")
    renameToFetchDelay = Param.Cycles(1, "Rename to fetch delay")
    iewToFetchDelay = Param.Cycles(1, "Issue/Execute/Writeback to fetch delay")
    commitToFetchDelay = Param.Cycles(1, "Commit to fetch delay")
    fetchWidth = Param.Unsigned(8, "Fetch width")
    fetchBufferSize = Param.Unsigned(64, "Fetch buffer size in bytes")
    fetchQueueSize = Param.Unsigned(
        32, "Fetch queue size in micro-ops per-thread"
    )

    renameToDecodeDelay = Param.Cycles(1, "Rename to decode delay")
    iewToDecodeDelay = Param.Cycles(
        1, "Issue/Execute/Writeback to decode delay"
    )
    commitToDecodeDelay = Param.Cycles(1, "Commit to decode delay")
    fetchToDecodeDelay = Param.Cycles(1, "Fetch to decode delay")
    decodeWidth = Param.Unsigned(8, "Decode width")

    iewToRenameDelay = Param.Cycles(
        1, "Issue/Execute/Writeback to rename delay"
    )
    commitToRenameDelay = Param.Cycles(1, "Commit to rename delay")
    decodeToRenameDelay = Param.Cycles(1, "Decode to rename delay")
    renameWidth = Param.Unsigned(8, "Rename width")

    commitToIEWDelay = Param.Cycles(
        1, "Commit to Issue/Execute/Writeback delay"
    )
    renameToIEWDelay = Param.Cycles(
        2, "Rename to Issue/Execute/Writeback delay"
    )
    issueToExecuteDelay = Param.Cycles(
        1, "Issue to execute delay (internal to the IEW stage)"
    )
    dispatchWidth = Param.Unsigned(8, "Dispatch width")
    issueWidth = Param.Unsigned(8, "Issue width")
    wbWidth = Param.Unsigned(8, "Writeback width")
    fuPool = Param.FUPool(DefaultFUPool(), "Functional Unit pool")

    iewToCommitDelay = Param.Cycles(
        1, "Issue/Execute/Writeback to commit delay"
    )
    renameToROBDelay = Param.Cycles(1, "Rename to reorder buffer delay")
    commitWidth = Param.Unsigned(8, "Commit width")
    squashWidth = Param.Unsigned(8, "Squash width")
    trapLatency = Param.Cycles(13, "Trap latency")
    fetchTrapLatency = Param.Cycles(1, "Fetch trap latency")

    backComSize = Param.Unsigned(
        5, "Time buffer size for backwards communication"
    )
    forwardComSize = Param.Unsigned(
        5, "Time buffer size for forward communication"
    )

    LQEntries = Param.Unsigned(32, "Number of load queue entries")
    SQEntries = Param.Unsigned(32, "Number of store queue entries")
    LSQDepCheckShift = Param.Unsigned(
        4, "Number of places to shift addr before check"
    )
    LSQCheckLoads = Param.Bool(
        True,
        "Should dependency violations be checked for "
        "loads & stores or just stores",
    )
    store_set_clear_period = Param.Unsigned(
        250000,
        "Number of load/store insts before the dep predictor "
        "should be invalidated",
    )
    LFSTSize = Param.Unsigned(1024, "Last fetched store table size")
    SSITSize = Param.Unsigned(1024, "Store set ID table size")

    numRobs = Param.Unsigned(1, "Number of Reorder Buffers")

    numPhysIntRegs = Param.Unsigned(
        256, "Number of physical integer registers"
    )
    numPhysFloatRegs = Param.Unsigned(
        256, "Number of physical floating point registers"
    )
    numPhysVecRegs = Param.Unsigned(256, "Number of physical vector registers")
    numPhysVecPredRegs = Param.Unsigned(
        32, "Number of physical predicate registers"
    )
    numPhysMatRegs = Param.Unsigned(2, "Number of physical matrix registers")
    # most ISAs don't use condition-code regs, so default is 0
    numPhysCCRegs = Param.Unsigned(0, "Number of physical cc registers")
    numIQEntries = Param.Unsigned(64, "Number of instruction queue entries")
    numROBEntries = Param.Unsigned(192, "Number of reorder buffer entries")

    smtNumFetchingThreads = Param.Unsigned(1, "SMT Number of Fetching Threads")
    smtFetchPolicy = Param.SMTFetchPolicy("RoundRobin", "SMT Fetch policy")
    smtLSQPolicy = Param.SMTQueuePolicy(
        "Partitioned", "SMT LSQ Sharing Policy"
    )
    smtLSQThreshold = Param.Int(100, "SMT LSQ Threshold Sharing Parameter")
    smtIQPolicy = Param.SMTQueuePolicy("Partitioned", "SMT IQ Sharing Policy")
    smtIQThreshold = Param.Int(100, "SMT IQ Threshold Sharing Parameter")
    smtROBPolicy = Param.SMTQueuePolicy(
        "Partitioned", "SMT ROB Sharing Policy"
    )
    smtROBThreshold = Param.Int(100, "SMT ROB Threshold Sharing Parameter")
    smtCommitPolicy = Param.CommitPolicy("RoundRobin", "SMT Commit Policy")

    branchPred = Param.BranchPredictor(
        TournamentBP(numThreads=Parent.numThreads), "Branch Predictor"
    )
    needsTSO = Param.Bool(False, "Enable TSO Memory model")