src/mem/cache/compressors/Compressors.py

   1 # Copyright (c) 2018-2020 Inria
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   4 # Redistribution and use in source and binary forms, with or without
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  14 #
  15 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  25 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26
  27 from m5.params import *
  28 from m5.proxy import *
  29 from m5.SimObject import SimObject
  30
  31 class BaseCacheCompressor(SimObject):
  32     type = 'BaseCacheCompressor'
  33     abstract = True
  34     cxx_class = 'Compressor::Base'
  35     cxx_header = "mem/cache/compressors/base.hh"
  36
  37     block_size = Param.Int(Parent.cache_line_size, "Block size in bytes")
  38     size_threshold = Param.Unsigned(Parent.cache_line_size, "Minimum size, "
  39         "in bytes, in which a block must be compressed to. Otherwise it is "
  40         "stored in its uncompressed state")
  41
  42 class BaseDictionaryCompressor(BaseCacheCompressor):
  43     type = 'BaseDictionaryCompressor'
  44     abstract = True
  45     cxx_class = 'Compressor::BaseDictionaryCompressor'
  46     cxx_header = "mem/cache/compressors/dictionary_compressor.hh"
  47
  48     dictionary_size = Param.Int(Parent.cache_line_size,
  49         "Number of dictionary entries")
  50
  51 class Base64Delta8(BaseDictionaryCompressor):
  52     type = 'Base64Delta8'
  53     cxx_class = 'Compressor::Base64Delta8'
  54     cxx_header = "mem/cache/compressors/base_delta.hh"
  55
  56 class Base64Delta16(BaseDictionaryCompressor):
  57     type = 'Base64Delta16'
  58     cxx_class = 'Compressor::Base64Delta16'
  59     cxx_header = "mem/cache/compressors/base_delta.hh"
  60
  61 class Base64Delta32(BaseDictionaryCompressor):
  62     type = 'Base64Delta32'
  63     cxx_class = 'Compressor::Base64Delta32'
  64     cxx_header = "mem/cache/compressors/base_delta.hh"
  65
  66 class Base32Delta8(BaseDictionaryCompressor):
  67     type = 'Base32Delta8'
  68     cxx_class = 'Compressor::Base32Delta8'
  69     cxx_header = "mem/cache/compressors/base_delta.hh"
  70
  71 class Base32Delta16(BaseDictionaryCompressor):
  72     type = 'Base32Delta16'
  73     cxx_class = 'Compressor::Base32Delta16'
  74     cxx_header = "mem/cache/compressors/base_delta.hh"
  75
  76 class Base16Delta8(BaseDictionaryCompressor):
  77     type = 'Base16Delta8'
  78     cxx_class = 'Compressor::Base16Delta8'
  79     cxx_header = "mem/cache/compressors/base_delta.hh"
  80
  81 class CPack(BaseDictionaryCompressor):
  82     type = 'CPack'
  83     cxx_class = 'Compressor::CPack'
  84     cxx_header = "mem/cache/compressors/cpack.hh"
  85
  86 class FPCD(BaseDictionaryCompressor):
  87     type = 'FPCD'
  88     cxx_class = 'Compressor::FPCD'
  89     cxx_header = "mem/cache/compressors/fpcd.hh"
  90
  91     dictionary_size = 2
  92
  93 class MultiCompressor(BaseCacheCompressor):
  94     type = 'MultiCompressor'
  95     cxx_class = 'Compressor::Multi'
  96     cxx_header = "mem/cache/compressors/multi.hh"
  97
  98     # Dummy default compressor list. This might not be an optimal choice,
  99     # since these compressors have many overlapping patterns
 100     compressors = VectorParam.BaseCacheCompressor([CPack(), FPCD()],
 101         "Array of compressors")
 102
 103 class PerfectCompressor(BaseCacheCompressor):
 104     type = 'PerfectCompressor'
 105     cxx_class = 'Compressor::Perfect'
 106     cxx_header = "mem/cache/compressors/perfect.hh"
 107
 108     max_compression_ratio = Param.Int(2,
 109         "Maximum compression ratio allowed")
 110     compression_latency = Param.Cycles(1,
 111         "Number of cycles to perform data compression")
 112     decompression_latency = Param.Cycles(1,
 113         "Number of cycles to perform data decompression")
 114
 115 class RepeatedQwordsCompressor(BaseDictionaryCompressor):
 116     type = 'RepeatedQwordsCompressor'
 117     cxx_class = 'Compressor::RepeatedQwords'
 118     cxx_header = "mem/cache/compressors/repeated_qwords.hh"
 119
 120 class ZeroCompressor(BaseDictionaryCompressor):
 121     type = 'ZeroCompressor'
 122     cxx_class = 'Compressor::Zero'
 123     cxx_header = "mem/cache/compressors/zero.hh"
 124
 125 class BDI(MultiCompressor):
 126     compressors = [ZeroCompressor(), RepeatedQwordsCompressor(),
 127         Base64Delta8(), Base64Delta16(), Base64Delta32(), Base32Delta8(),
 128         Base32Delta16(), Base16Delta8()]