src/mem/cache/prefetch/Prefetcher.py

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  13 # Copyright (c) 2005 The Regents of The University of Michigan
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  38 #
  39 # Authors: Ron Dreslinski
  40 #          Mitch Hayenga
  41
  42 from ClockedObject import ClockedObject
  43 from m5.params import *
  44 from m5.proxy import *
  45
  46 class BasePrefetcher(ClockedObject):
  47     type = 'BasePrefetcher'
  48     abstract = True
  49     cxx_header = "mem/cache/prefetch/base.hh"
  50     sys = Param.System(Parent.any, "System this prefetcher belongs to")
  51
  52     on_miss = Param.Bool(False, "Only notify prefetcher on misses")
  53     on_read = Param.Bool(True, "Notify prefetcher on reads")
  54     on_write = Param.Bool(True, "Notify prefetcher on writes")
  55     on_data  = Param.Bool(True, "Notify prefetcher on data accesses")
  56     on_inst  = Param.Bool(True, "Notify prefetcher on instruction accesses")
  57
  58 class QueuedPrefetcher(BasePrefetcher):
  59     type = "QueuedPrefetcher"
  60     abstract = True
  61     cxx_class = "QueuedPrefetcher"
  62     cxx_header = "mem/cache/prefetch/queued.hh"
  63     latency = Param.Int(1, "Latency for generated prefetches")
  64     queue_size = Param.Int(32, "Maximum number of queued prefetches")
  65     queue_squash = Param.Bool(True, "Squash queued prefetch on demand access")
  66     queue_filter = Param.Bool(True, "Don't queue redundant prefetches")
  67     cache_snoop = Param.Bool(False, "Snoop cache to eliminate redundant request")
  68
  69     tag_prefetch = Param.Bool(True, "Tag prefetch with PC of generating access")
  70
  71 class StridePrefetcher(QueuedPrefetcher):
  72     type = 'StridePrefetcher'
  73     cxx_class = 'StridePrefetcher'
  74     cxx_header = "mem/cache/prefetch/stride.hh"
  75
  76     max_conf = Param.Int(7, "Maximum confidence level")
  77     thresh_conf = Param.Int(4, "Threshold confidence level")
  78     min_conf = Param.Int(0, "Minimum confidence level")
  79     start_conf = Param.Int(4, "Starting confidence for new entries")
  80
  81     table_sets = Param.Int(16, "Number of sets in PC lookup table")
  82     table_assoc = Param.Int(4, "Associativity of PC lookup table")
  83     use_master_id = Param.Bool(True, "Use master id based history")
  84
  85     degree = Param.Int(4, "Number of prefetches to generate")
  86
  87 class TaggedPrefetcher(QueuedPrefetcher):
  88     type = 'TaggedPrefetcher'
  89     cxx_class = 'TaggedPrefetcher'
  90     cxx_header = "mem/cache/prefetch/tagged.hh"
  91
  92     degree = Param.Int(2, "Number of prefetches to generate")