# Copyright (c) 2012, 2014 ARM Limited # All rights reserved. # # The license below extends only to copyright in the software and shall # not be construed as granting a license to any other intellectual # property including but not limited to intellectual property relating # to a hardware implementation of the functionality of the software # licensed hereunder. You may use the software subject to the license # terms below provided that you ensure that this notice is replicated # unmodified and in its entirety in all distributions of the software, # modified or unmodified, in source code or in binary form. # # Copyright (c) 2005 The Regents of The University of Michigan # All rights reserved. # # Redistribution and use in source and binary forms, with or without # modification, are permitted provided that the following conditions are # met: redistributions of source code must retain the above copyright # notice, this list of conditions and the following disclaimer; # redistributions in binary form must reproduce the above copyright # notice, this list of conditions and the following disclaimer in the # documentation and/or other materials provided with the distribution; # neither the name of the copyright holders nor the names of its # contributors may be used to endorse or promote products derived from # this software without specific prior written permission. # # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT # 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 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. # # Authors: Ron Dreslinski # Mitch Hayenga from m5.SimObject import * from m5.params import * from m5.proxy import * 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 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")