text: # Copyright (c) 2012, 2014 ARM Limited
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  #
  # 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 AccessMapPatternMatchingPrefetcher(QueuedPrefetcher):
      type = 'AccessMapPatternMatchingPrefetcher'
      cxx_class = 'AccessMapPatternMatchingPrefetcher'
      cxx_header = "mem/cache/prefetch/access_map_pattern_matching.hh"
  
      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 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")
  