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# Copyright (c) 2005 The Regents of The University of Michigan
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# this software without specific prior written permission.
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# 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
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# Authors: Ron Dreslinski
# Mitch Hayenga
from m5.SimObject import *
from m5.params import *
from m5.proxy import *
from m5.objects.BaseCPU import BaseCPU
from m5.objects.ClockedObject import ClockedObject
from m5.objects.IndexingPolicies import *
from m5.objects.ReplacementPolicies import *
class HWPProbeEvent(object):
def __init__(self, prefetcher, obj, *listOfNames):
self.obj = obj
self.prefetcher = prefetcher
self.names = listOfNames
def register(self):
if self.obj:
for name in self.names:
self.prefetcher.getCCObject().addEventProbe(
self.obj.getCCObject(), name)
class BasePrefetcher(ClockedObject):
type = 'BasePrefetcher'
abstract = True
cxx_header = "mem/cache/prefetch/base.hh"
cxx_exports = [
PyBindMethod("addEventProbe"),
]
sys = Param.System(Parent.any, "System this prefetcher belongs to")
# Get the block size from the parent (system)
block_size = Param.Int(Parent.cache_line_size, "Block size in bytes")
on_miss = Param.Bool(False, "Only notify prefetcher on misses")
on_read = Param.Bool(True, "Notify prefetcher on reads")
on_write = Param.Bool(True, "Notify prefetcher on writes")
on_data = Param.Bool(True, "Notify prefetcher on data accesses")
on_inst = Param.Bool(True, "Notify prefetcher on instruction accesses")
prefetch_on_access = Param.Bool(Parent.prefetch_on_access,
"Notify the hardware prefetcher on every access (not just misses)")
use_virtual_addresses = Param.Bool(False,
"Use virtual addresses for prefetching")
_events = []
def addEvent(self, newObject):
self._events.append(newObject)
# Override the normal SimObject::regProbeListeners method and
# register deferred event handlers.
def regProbeListeners(self):
for event in self._events:
event.register()
self.getCCObject().regProbeListeners()
def listenFromProbe(self, simObj, *probeNames):
if not isinstance(simObj, SimObject):
raise TypeError("argument must be of SimObject type")
if len(probeNames) <= 0:
raise TypeError("probeNames must have at least one element")
self.addEvent(HWPProbeEvent(self, simObj, *probeNames))
class QueuedPrefetcher(BasePrefetcher):
type = "QueuedPrefetcher"
abstract = True
cxx_class = "QueuedPrefetcher"
cxx_header = "mem/cache/prefetch/queued.hh"
latency = Param.Int(1, "Latency for generated prefetches")
queue_size = Param.Int(32, "Maximum number of queued prefetches")
queue_squash = Param.Bool(True, "Squash queued prefetch on demand access")
queue_filter = Param.Bool(True, "Don't queue redundant prefetches")
cache_snoop = Param.Bool(False, "Snoop cache to eliminate redundant request")
tag_prefetch = Param.Bool(True, "Tag prefetch with PC of generating access")
class StridePrefetcher(QueuedPrefetcher):
type = 'StridePrefetcher'
cxx_class = 'StridePrefetcher'
cxx_header = "mem/cache/prefetch/stride.hh"
# Do not consult stride prefetcher on instruction accesses
on_inst = False
max_conf = Param.Int(7, "Maximum confidence level")
thresh_conf = Param.Int(4, "Threshold confidence level")
min_conf = Param.Int(0, "Minimum confidence level")
start_conf = Param.Int(4, "Starting confidence for new entries")
table_sets = Param.Int(16, "Number of sets in PC lookup table")
table_assoc = Param.Int(4, "Associativity of PC lookup table")
use_master_id = Param.Bool(True, "Use master id based history")
degree = Param.Int(4, "Number of prefetches to generate")
# Get replacement policy
replacement_policy = Param.BaseReplacementPolicy(RandomRP(),
"Replacement policy")
class TaggedPrefetcher(QueuedPrefetcher):
type = 'TaggedPrefetcher'
cxx_class = 'TaggedPrefetcher'
cxx_header = "mem/cache/prefetch/tagged.hh"
degree = Param.Int(2, "Number of prefetches to generate")
class IndirectMemoryPrefetcher(QueuedPrefetcher):
type = 'IndirectMemoryPrefetcher'
cxx_class = 'IndirectMemoryPrefetcher'
cxx_header = "mem/cache/prefetch/indirect_memory.hh"
pt_table_entries = Param.MemorySize("16",
"Number of entries of the Prefetch Table")
pt_table_assoc = Param.Unsigned(16, "Associativity of the Prefetch Table")
pt_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.pt_table_assoc,
size = Parent.pt_table_entries),
"Indexing policy of the pattern table")
pt_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the pattern table")
max_prefetch_distance = Param.Unsigned(16, "Maximum prefetch distance")
max_indirect_counter_value = Param.Unsigned(8,
"Maximum value of the indirect counter")
ipd_table_entries = Param.MemorySize("4",
"Number of entries of the Indirect Pattern Detector")
ipd_table_assoc = Param.Unsigned(4,
"Associativity of the Indirect Pattern Detector")
ipd_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.ipd_table_assoc,
size = Parent.ipd_table_entries),
"Indexing policy of the Indirect Pattern Detector")
ipd_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the Indirect Pattern Detector")
shift_values = VectorParam.Int([2, 3, 4, -3], "Shift values to evaluate")
addr_array_len = Param.Unsigned(4, "Number of misses tracked")
prefetch_threshold = Param.Unsigned(2,
"Counter threshold to start the indirect prefetching")
stream_counter_threshold = Param.Unsigned(4,
"Counter threshold to enable the stream prefetcher")
streaming_distance = Param.Unsigned(4,
"Number of prefetches to generate when using the stream prefetcher")
class SignaturePathPrefetcher(QueuedPrefetcher):
type = 'SignaturePathPrefetcher'
cxx_class = 'SignaturePathPrefetcher'
cxx_header = "mem/cache/prefetch/signature_path.hh"
signature_shift = Param.UInt8(3,
"Number of bits to shift when calculating a new signature");
signature_bits = Param.UInt16(12,
"Size of the signature, in bits");
signature_table_entries = Param.MemorySize("1024",
"Number of entries of the signature table")
signature_table_assoc = Param.Unsigned(2,
"Associativity of the signature table")
signature_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.signature_table_assoc,
size = Parent.signature_table_entries),
"Indexing policy of the signature table")
signature_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the signature table")
max_counter_value = Param.UInt8(7, "Maximum pattern counter value")
pattern_table_entries = Param.MemorySize("4096",
"Number of entries of the pattern table")
pattern_table_assoc = Param.Unsigned(1,
"Associativity of the pattern table")
strides_per_pattern_entry = Param.Unsigned(4,
"Number of strides stored in each pattern entry")
pattern_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.pattern_table_assoc,
size = Parent.pattern_table_entries),
"Indexing policy of the pattern table")
pattern_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the pattern table")
prefetch_confidence_threshold = Param.Float(0.5,
"Minimum confidence to issue prefetches")
lookahead_confidence_threshold = Param.Float(0.75,
"Minimum confidence to continue exploring lookahead entries")
class SignaturePathPrefetcherV2(SignaturePathPrefetcher):
type = 'SignaturePathPrefetcherV2'
cxx_class = 'SignaturePathPrefetcherV2'
cxx_header = "mem/cache/prefetch/signature_path_v2.hh"
signature_table_entries = "256"
signature_table_assoc = 1
pattern_table_entries = "512"
pattern_table_assoc = 1
max_counter_value = 15
prefetch_confidence_threshold = 0.25
lookahead_confidence_threshold = 0.25
global_history_register_entries = Param.MemorySize("8",
"Number of entries of global history register")
global_history_register_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1,
assoc = Parent.global_history_register_entries,
size = Parent.global_history_register_entries),
"Indexing policy of the global history register")
global_history_register_replacement_policy = Param.BaseReplacementPolicy(
LRURP(), "Replacement policy of the global history register")
class AccessMapPatternMatching(ClockedObject):
type = 'AccessMapPatternMatching'
cxx_class = 'AccessMapPatternMatching'
cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"
block_size = Param.Unsigned(Parent.block_size,
"Cacheline size used by the prefetcher using this object")
limit_stride = Param.Unsigned(0,
"Limit the strides checked up to -X/X, if 0, disable the limit")
start_degree = Param.Unsigned(4,
"Initial degree (Maximum number of prefetches generated")
hot_zone_size = Param.MemorySize("2kB", "Memory covered by a hot zone")
access_map_table_entries = Param.MemorySize("256",
"Number of entries in the access map table")
access_map_table_assoc = Param.Unsigned(8,
"Associativity of the access map table")
access_map_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.access_map_table_assoc,
size = Parent.access_map_table_entries),
"Indexing policy of the access map table")
access_map_table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the access map table")
high_coverage_threshold = Param.Float(0.25,
"A prefetch coverage factor bigger than this is considered high")
low_coverage_threshold = Param.Float(0.125,
"A prefetch coverage factor smaller than this is considered low")
high_accuracy_threshold = Param.Float(0.5,
"A prefetch accuracy factor bigger than this is considered high")
low_accuracy_threshold = Param.Float(0.25,
"A prefetch accuracy factor smaller than this is considered low")
high_cache_hit_threshold = Param.Float(0.875,
"A cache hit ratio bigger than this is considered high")
low_cache_hit_threshold = Param.Float(0.75,
"A cache hit ratio smaller than this is considered low")
epoch_cycles = Param.Cycles(256000, "Cycles in an epoch period")
offchip_memory_latency = Param.Latency("30ns",
"Memory latency used to compute the required memory bandwidth")
class AMPMPrefetcher(QueuedPrefetcher):
type = 'AMPMPrefetcher'
cxx_class = 'AMPMPrefetcher'
cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"
ampm = Param.AccessMapPatternMatching( AccessMapPatternMatching(),
"Access Map Pattern Matching object")
class DeltaCorrelatingPredictionTables(SimObject):
type = 'DeltaCorrelatingPredictionTables'
cxx_class = 'DeltaCorrelatingPredictionTables'
cxx_header = "mem/cache/prefetch/delta_correlating_prediction_tables.hh"
deltas_per_entry = Param.Unsigned(20,
"Number of deltas stored in each table entry")
delta_bits = Param.Unsigned(12, "Bits per delta")
delta_mask_bits = Param.Unsigned(8,
"Lower bits to mask when comparing deltas")
table_entries = Param.MemorySize("128",
"Number of entries in the table")
table_assoc = Param.Unsigned(128,
"Associativity of the table")
table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.table_assoc,
size = Parent.table_entries),
"Indexing policy of the table")
table_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the table")
class DCPTPrefetcher(QueuedPrefetcher):
type = 'DCPTPrefetcher'
cxx_class = 'DCPTPrefetcher'
cxx_header = "mem/cache/prefetch/delta_correlating_prediction_tables.hh"
dcpt = Param.DeltaCorrelatingPredictionTables(
DeltaCorrelatingPredictionTables(),
"Delta Correlating Prediction Tables object")
class IrregularStreamBufferPrefetcher(QueuedPrefetcher):
type = "IrregularStreamBufferPrefetcher"
cxx_class = "IrregularStreamBufferPrefetcher"
cxx_header = "mem/cache/prefetch/irregular_stream_buffer.hh"
max_counter_value = Param.Unsigned(3,
"Maximum value of the confidence counter")
chunk_size = Param.Unsigned(256,
"Maximum number of addresses in a temporal stream")
degree = Param.Unsigned(4, "Number of prefetches to generate")
training_unit_assoc = Param.Unsigned(128,
"Associativity of the training unit")
training_unit_entries = Param.MemorySize("128",
"Number of entries of the training unit")
training_unit_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.training_unit_assoc,
size = Parent.training_unit_entries),
"Indexing policy of the training unit")
training_unit_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the training unit")
prefetch_candidates_per_entry = Param.Unsigned(16,
"Number of prefetch candidates stored in a SP-AMC entry")
address_map_cache_assoc = Param.Unsigned(128,
"Associativity of the PS/SP AMCs")
address_map_cache_entries = Param.MemorySize("128",
"Number of entries of the PS/SP AMCs")
ps_address_map_cache_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1,
assoc = Parent.address_map_cache_assoc,
size = Parent.address_map_cache_entries),
"Indexing policy of the Physical-to-Structural Address Map Cache")
ps_address_map_cache_replacement_policy = Param.BaseReplacementPolicy(
LRURP(),
"Replacement policy of the Physical-to-Structural Address Map Cache")
sp_address_map_cache_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1,
assoc = Parent.address_map_cache_assoc,
size = Parent.address_map_cache_entries),
"Indexing policy of the Structural-to-Physical Address Mao Cache")
sp_address_map_cache_replacement_policy = Param.BaseReplacementPolicy(
LRURP(),
"Replacement policy of the Structural-to-Physical Address Map Cache")
class SlimAccessMapPatternMatching(AccessMapPatternMatching):
start_degree = 2
limit_stride = 4
class SlimDeltaCorrelatingPredictionTables(DeltaCorrelatingPredictionTables):
table_entries = "256"
table_assoc = 256
deltas_per_entry = 9
class SlimAMPMPrefetcher(QueuedPrefetcher):
type = 'SlimAMPMPrefetcher'
cxx_class = 'SlimAMPMPrefetcher'
cxx_header = "mem/cache/prefetch/slim_ampm.hh"
ampm = Param.AccessMapPatternMatching(SlimAccessMapPatternMatching(),
"Access Map Pattern Matching object")
dcpt = Param.DeltaCorrelatingPredictionTables(
SlimDeltaCorrelatingPredictionTables(),
"Delta Correlating Prediction Tables object")
class BOPPrefetcher(QueuedPrefetcher):
type = "BOPPrefetcher"
cxx_class = "BOPPrefetcher"
cxx_header = "mem/cache/prefetch/bop.hh"
score_max = Param.Unsigned(31, "Max. score to update the best offset")
round_max = Param.Unsigned(100, "Max. round to update the best offset")
bad_score = Param.Unsigned(10, "Score at which the HWP is disabled")
rr_size = Param.Unsigned(64, "Number of entries of each RR bank")
tag_bits = Param.Unsigned(12, "Bits used to store the tag")
offset_list_size = Param.Unsigned(46,
"Number of entries in the offsets list")
negative_offsets_enable = Param.Bool(True,
"Initialize the offsets list also with negative values \
(i.e. the table will have half of the entries with positive \
offsets and the other half with negative ones)")
delay_queue_enable = Param.Bool(True, "Enable the delay queue")
delay_queue_size = Param.Unsigned(15,
"Number of entries in the delay queue")
delay_queue_cycles = Param.Cycles(60,
"Cycles to delay a write in the left RR table from the delay \
queue")
class SBOOEPrefetcher(QueuedPrefetcher):
type = 'SBOOEPrefetcher'
cxx_class = 'SBOOEPrefetcher'
cxx_header = "mem/cache/prefetch/sbooe.hh"
latency_buffer_size = Param.Int(32, "Entries in the latency buffer")
sequential_prefetchers = Param.Int(9, "Number of sequential prefetchers")
sandbox_entries = Param.Int(1024, "Size of the address buffer")
score_threshold_pct = Param.Percent(25, "Min. threshold to issue a \
prefetch. The value is the percentage of sandbox entries to use")
class STeMSPrefetcher(QueuedPrefetcher):
type = "STeMSPrefetcher"
cxx_class = "STeMSPrefetcher"
cxx_header = "mem/cache/prefetch/spatio_temporal_memory_streaming.hh"
spatial_region_size = Param.MemorySize("2kB",
"Memory covered by a hot zone")
active_generation_table_entries = Param.MemorySize("64",
"Number of entries in the active generation table")
active_generation_table_assoc = Param.Unsigned(64,
"Associativity of the active generation table")
active_generation_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1,
assoc = Parent.active_generation_table_assoc,
size = Parent.active_generation_table_entries),
"Indexing policy of the active generation table")
active_generation_table_replacement_policy = Param.BaseReplacementPolicy(
LRURP(), "Replacement policy of the active generation table")
pattern_sequence_table_entries = Param.MemorySize("16384",
"Number of entries in the pattern sequence table")
pattern_sequence_table_assoc = Param.Unsigned(16384,
"Associativity of the pattern sequence table")
pattern_sequence_table_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1,
assoc = Parent.pattern_sequence_table_assoc,
size = Parent.pattern_sequence_table_entries),
"Indexing policy of the pattern sequence table")
pattern_sequence_table_replacement_policy = Param.BaseReplacementPolicy(
LRURP(), "Replacement policy of the pattern sequence table")
region_miss_order_buffer_entries = Param.Unsigned(131072,
"Number of entries of the Region Miss Order Buffer")
reconstruction_entries = Param.Unsigned(256,
"Number of reconstruction entries")
class HWPProbeEventRetiredInsts(HWPProbeEvent):
def register(self):
if self.obj:
for name in self.names:
self.prefetcher.getCCObject().addEventProbeRetiredInsts(
self.obj.getCCObject(), name)
class PIFPrefetcher(QueuedPrefetcher):
type = 'PIFPrefetcher'
cxx_class = 'PIFPrefetcher'
cxx_header = "mem/cache/prefetch/pif.hh"
cxx_exports = [
PyBindMethod("addEventProbeRetiredInsts"),
]
prec_spatial_region_bits = Param.Unsigned(2,
"Number of preceding addresses in the spatial region")
succ_spatial_region_bits = Param.Unsigned(8,
"Number of subsequent addresses in the spatial region")
compactor_entries = Param.Unsigned(2, "Entries in the temp. compactor")
stream_address_buffer_entries = Param.Unsigned(7, "Entries in the SAB")
history_buffer_size = Param.Unsigned(16, "Entries in the history buffer")
index_entries = Param.MemorySize("64",
"Number of entries in the index")
index_assoc = Param.Unsigned(64,
"Associativity of the index")
index_indexing_policy = Param.BaseIndexingPolicy(
SetAssociative(entry_size = 1, assoc = Parent.index_assoc,
size = Parent.index_entries),
"Indexing policy of the index")
index_replacement_policy = Param.BaseReplacementPolicy(LRURP(),
"Replacement policy of the index")
def listenFromProbeRetiredInstructions(self, simObj):
if not isinstance(simObj, BaseCPU):
raise TypeError("argument must be of BaseCPU type")
self.addEvent(HWPProbeEventRetiredInsts(self, simObj,"RetiredInstsPC"))