src/mem/cache/compressors/Compressors.py

   1 # Copyright (c) 2018-2020 Inria
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  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     chunk_size_bits = Param.Unsigned(32,
  39         "Size of a parsing data chunk (in bits)")
  40     size_threshold = Param.Unsigned(Parent.cache_line_size, "Minimum size, "
  41         "in bytes, in which a block must be compressed to. Otherwise it is "
  42         "stored in its uncompressed state")
  43
  44 class BaseDictionaryCompressor(BaseCacheCompressor):
  45     type = 'BaseDictionaryCompressor'
  46     abstract = True
  47     cxx_class = 'Compressor::BaseDictionaryCompressor'
  48     cxx_header = "mem/cache/compressors/dictionary_compressor.hh"
  49
  50     dictionary_size = Param.Int(Parent.cache_line_size,
  51         "Number of dictionary entries")
  52
  53 class Base64Delta8(BaseDictionaryCompressor):
  54     type = 'Base64Delta8'
  55     cxx_class = 'Compressor::Base64Delta8'
  56     cxx_header = "mem/cache/compressors/base_delta.hh"
  57
  58     chunk_size_bits = 64
  59
  60 class Base64Delta16(BaseDictionaryCompressor):
  61     type = 'Base64Delta16'
  62     cxx_class = 'Compressor::Base64Delta16'
  63     cxx_header = "mem/cache/compressors/base_delta.hh"
  64
  65     chunk_size_bits = 64
  66
  67 class Base64Delta32(BaseDictionaryCompressor):
  68     type = 'Base64Delta32'
  69     cxx_class = 'Compressor::Base64Delta32'
  70     cxx_header = "mem/cache/compressors/base_delta.hh"
  71
  72     chunk_size_bits = 64
  73
  74 class Base32Delta8(BaseDictionaryCompressor):
  75     type = 'Base32Delta8'
  76     cxx_class = 'Compressor::Base32Delta8'
  77     cxx_header = "mem/cache/compressors/base_delta.hh"
  78
  79     chunk_size_bits = 32
  80
  81 class Base32Delta16(BaseDictionaryCompressor):
  82     type = 'Base32Delta16'
  83     cxx_class = 'Compressor::Base32Delta16'
  84     cxx_header = "mem/cache/compressors/base_delta.hh"
  85
  86     chunk_size_bits = 32
  87
  88 class Base16Delta8(BaseDictionaryCompressor):
  89     type = 'Base16Delta8'
  90     cxx_class = 'Compressor::Base16Delta8'
  91     cxx_header = "mem/cache/compressors/base_delta.hh"
  92
  93     chunk_size_bits = 16
  94
  95 class CPack(BaseDictionaryCompressor):
  96     type = 'CPack'
  97     cxx_class = 'Compressor::CPack'
  98     cxx_header = "mem/cache/compressors/cpack.hh"
  99
 100 class FPCD(BaseDictionaryCompressor):
 101     type = 'FPCD'
 102     cxx_class = 'Compressor::FPCD'
 103     cxx_header = "mem/cache/compressors/fpcd.hh"
 104
 105     dictionary_size = 2
 106
 107 class MultiCompressor(BaseCacheCompressor):
 108     type = 'MultiCompressor'
 109     cxx_class = 'Compressor::Multi'
 110     cxx_header = "mem/cache/compressors/multi.hh"
 111
 112     # Dummy default compressor list. This might not be an optimal choice,
 113     # since these compressors have many overlapping patterns
 114     compressors = VectorParam.BaseCacheCompressor([CPack(), FPCD()],
 115         "Array of compressors")
 116     encoding_in_tags = Param.Bool(False, "If set the bits to inform which "
 117         "sub-compressor compressed some data are added to its corresponding "
 118         "tag entry.")
 119
 120 class PerfectCompressor(BaseCacheCompressor):
 121     type = 'PerfectCompressor'
 122     cxx_class = 'Compressor::Perfect'
 123     cxx_header = "mem/cache/compressors/perfect.hh"
 124
 125     chunk_size_bits = 64
 126     max_compression_ratio = Param.Int(2,
 127         "Maximum compression ratio allowed")
 128     compression_latency = Param.Cycles(1,
 129         "Number of cycles to perform data compression")
 130     decompression_latency = Param.Cycles(1,
 131         "Number of cycles to perform data decompression")
 132
 133 class RepeatedQwordsCompressor(BaseDictionaryCompressor):
 134     type = 'RepeatedQwordsCompressor'
 135     cxx_class = 'Compressor::RepeatedQwords'
 136     cxx_header = "mem/cache/compressors/repeated_qwords.hh"
 137
 138     chunk_size_bits = 64
 139
 140 class ZeroCompressor(BaseDictionaryCompressor):
 141     type = 'ZeroCompressor'
 142     cxx_class = 'Compressor::Zero'
 143     cxx_header = "mem/cache/compressors/zero.hh"
 144
 145     chunk_size_bits = 64
 146
 147 class BDI(MultiCompressor):
 148     encoding_in_tags=True
 149     compressors = [ZeroCompressor(), RepeatedQwordsCompressor(),
 150         Base64Delta8(), Base64Delta16(), Base64Delta32(), Base32Delta8(),
 151         Base32Delta16(), Base16Delta8()]