Prefetcher.py revision 10623 
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13# Copyright (c) 2005 The Regents of The University of Michigan
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39# Authors: Ron Dreslinski
40#          Mitch Hayenga
41
42from ClockedObject import ClockedObject
43from m5.params import *
44from m5.proxy import *
45
46class 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
58class 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
71class 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
87class 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")
93