# Copyright 2021 Google, Inc.
#
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from m5.proxy import Self

from m5.objects.BaseAtomicSimpleCPU import BaseAtomicSimpleCPU
from m5.objects.BaseNonCachingSimpleCPU import BaseNonCachingSimpleCPU
from m5.objects.BaseTimingSimpleCPU import BaseTimingSimpleCPU
from m5.objects.BaseO3CPU import BaseO3CPU
from m5.objects.BaseMinorCPU import BaseMinorCPU
from m5.objects.FuncUnit import *
from m5.objects.FUPool import *
from m5.objects.X86Decoder import X86Decoder
from m5.objects.X86MMU import X86MMU
from m5.objects.X86LocalApic import X86LocalApic
from m5.objects.X86ISA import X86ISA


class X86CPU:
    ArchDecoder = X86Decoder
    ArchMMU = X86MMU
    ArchInterrupts = X86LocalApic
    ArchISA = X86ISA


class X86AtomicSimpleCPU(BaseAtomicSimpleCPU, X86CPU):
    mmu = X86MMU()


class X86NonCachingSimpleCPU(BaseNonCachingSimpleCPU, X86CPU):
    mmu = X86MMU()


class X86TimingSimpleCPU(BaseTimingSimpleCPU, X86CPU):
    mmu = X86MMU()


class X86IntMultDiv(IntMultDiv):
    # DIV and IDIV instructions in x86 are implemented using a loop which
    # issues division microops.  The latency of these microops should really be
    # one (or a small number) cycle each since each of these computes one bit
    # of the quotient.
    opList = [
        OpDesc(opClass="IntMult", opLat=3),
        OpDesc(opClass="IntDiv", opLat=1, pipelined=False),
    ]

    count = 2


class DefaultX86FUPool(FUPool):
    FUList = [
        IntALU(),
        X86IntMultDiv(),
        FP_ALU(),
        FP_MultDiv(),
        ReadPort(),
        SIMD_Unit(),
        PredALU(),
        WritePort(),
        RdWrPort(),
        IprPort(),
    ]


class X86O3CPU(BaseO3CPU, X86CPU):
    mmu = X86MMU()
    needsTSO = True

    # For x86, each CC reg is used to hold only a subset of the
    # flags, so we need 4-5 times the number of CC regs as
    # physical integer regs to be sure we don't run out.  In
    # typical real machines, CC regs are not explicitly renamed
    # (it's a side effect of int reg renaming), so they should
    # never be the bottleneck here.
    numPhysCCRegs = Self.numPhysIntRegs * 5

    # DIV and IDIV instructions in x86 are implemented using a loop which
    # issues division microops.  The latency of these microops should really be
    # one (or a small number) cycle each since each of these computes one bit
    # of the quotient.
    fuPool = DefaultX86FUPool()


class X86MinorCPU(BaseMinorCPU, X86CPU):
    mmu = X86MMU()