# Copyright (c) 2012 The Regents of The University of Michigan
# Copyright (c) 2016 Centre National de la Recherche Scientifique
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from m5.objects import *

#-----------------------------------------------------------------------
#                ex5 LITTLE core (based on the ARM Cortex-A7)
#-----------------------------------------------------------------------

# Simple ALU Instructions have a latency of 3
class ex5_LITTLE_Simple_Int(MinorDefaultIntFU):
    opList = [ OpDesc(opClass='IntAlu', opLat=4) ]

# Complex ALU instructions have a variable latencies
class ex5_LITTLE_Complex_IntMul(MinorDefaultIntMulFU):
    opList = [ OpDesc(opClass='IntMult', opLat=7) ]

class ex5_LITTLE_Complex_IntDiv(MinorDefaultIntDivFU):
    opList = [ OpDesc(opClass='IntDiv', opLat=9) ]

# Floating point and SIMD instructions
class ex5_LITTLE_FP(MinorDefaultFloatSimdFU):
    opList = [ OpDesc(opClass='SimdAdd', opLat=6),
               OpDesc(opClass='SimdAddAcc', opLat=4),
               OpDesc(opClass='SimdAlu', opLat=4),
               OpDesc(opClass='SimdCmp', opLat=1),
               OpDesc(opClass='SimdCvt', opLat=3),
               OpDesc(opClass='SimdMisc', opLat=3),
               OpDesc(opClass='SimdMult',opLat=4),
               OpDesc(opClass='SimdMultAcc',opLat=5),
               OpDesc(opClass='SimdShift',opLat=3),
               OpDesc(opClass='SimdShiftAcc', opLat=3),
               OpDesc(opClass='SimdSqrt', opLat=9),
               OpDesc(opClass='SimdFloatAdd',opLat=8),
               OpDesc(opClass='SimdFloatAlu',opLat=6),
               OpDesc(opClass='SimdFloatCmp', opLat=6),
               OpDesc(opClass='SimdFloatCvt', opLat=6),
               OpDesc(opClass='SimdFloatDiv', opLat=20, pipelined=False),
               OpDesc(opClass='SimdFloatMisc', opLat=6),
               OpDesc(opClass='SimdFloatMult', opLat=15),
               OpDesc(opClass='SimdFloatMultAcc',opLat=6),
               OpDesc(opClass='SimdFloatSqrt', opLat=17),
               OpDesc(opClass='FloatAdd', opLat=8),
               OpDesc(opClass='FloatCmp', opLat=6),
               OpDesc(opClass='FloatCvt', opLat=6),
               OpDesc(opClass='FloatDiv', opLat=15, pipelined=False),
               OpDesc(opClass='FloatSqrt', opLat=33),
               OpDesc(opClass='FloatMult', opLat=6) ]

# Load/Store Units
class ex5_LITTLE_MemFU(MinorDefaultMemFU):
    opList = [ OpDesc(opClass='MemRead',opLat=1),
               OpDesc(opClass='MemWrite',opLat=1) ]

# Misc Unit
class ex5_LITTLE_MiscFU(MinorDefaultMiscFU):
    opList = [ OpDesc(opClass='IprAccess',opLat=1),
               OpDesc(opClass='InstPrefetch',opLat=1) ]

# Functional Units for this CPU
class ex5_LITTLE_FUP(MinorFUPool):
    funcUnits = [ex5_LITTLE_Simple_Int(), ex5_LITTLE_Simple_Int(),
        ex5_LITTLE_Complex_IntMul(), ex5_LITTLE_Complex_IntDiv(),
        ex5_LITTLE_FP(), ex5_LITTLE_MemFU(),
        ex5_LITTLE_MiscFU()]

class ex5_LITTLE(MinorCPU):
    executeFuncUnits = ex5_LITTLE_FUP()

class L1Cache(Cache):
    tag_latency = 2
    data_latency = 2
    response_latency = 2
    tgts_per_mshr = 8
    # Consider the L2 a victim cache also for clean lines
    writeback_clean = True

class L1I(L1Cache):
    mshrs = 2
    size = '32kB'
    assoc = 2
    is_read_only = True
    tgts_per_mshr = 20

class L1D(L1Cache):
    mshrs = 4
    size = '32kB'
    assoc = 4
    write_buffers = 4

# TLB Cache
# Use a cache as a L2 TLB
class WalkCache(Cache):
    tag_latency = 2
    data_latency = 2
    response_latency = 2
    mshrs = 6
    tgts_per_mshr = 8
    size = '1kB'
    assoc = 2
    write_buffers = 16
    is_read_only = True
    # Writeback clean lines as well
    writeback_clean = True

# L2 Cache
class L2(Cache):
    tag_latency = 9
    data_latency = 9
    response_latency = 9
    mshrs = 8
    tgts_per_mshr = 12
    size = '512kB'
    assoc = 8
    write_buffers = 16
    prefetch_on_access = True
    clusivity = 'mostly_excl'
    # Simple stride prefetcher
    prefetcher = StridePrefetcher(degree=1, latency = 1)
    tags = BaseSetAssoc()
    replacement_policy = RandomRP()
