src/mem/cache/compressors/cpack.cc

   1 /*
   2  * Copyright (c) 2018-2020 Inria
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
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   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @file
  30  * Implementation of the CPack cache compressor.
  31  */
  32
  33 #include "mem/cache/compressors/cpack.hh"
  34
  35 #include "mem/cache/compressors/dictionary_compressor_impl.hh"
  36 #include "params/CPack.hh"
  37
  38 namespace Compressor {
  39
  40 CPack::CPack(const Params *p)
  41     : DictionaryCompressor<uint32_t>(p)
  42 {
  43 }
  44
  45 void
  46 CPack::addToDictionary(DictionaryEntry data)
  47 {
  48     assert(numEntries < dictionarySize);
  49     dictionary[numEntries++] = data;
  50 }
  51
  52 std::unique_ptr<Base::CompressionData>
  53 CPack::compress(const std::vector<Chunk>& chunks,
  54     Cycles& comp_lat, Cycles& decomp_lat)
  55 {
  56     std::unique_ptr<Base::CompressionData> comp_data =
  57         DictionaryCompressor<uint32_t>::compress(chunks);
  58
  59     // Set compression latency (Accounts for pattern matching, length
  60     // generation, packaging and shifting)
  61     comp_lat = Cycles(blkSize/8+5);
  62
  63     // Set decompression latency (1 qword per cycle)
  64     decomp_lat = Cycles(blkSize/8);
  65
  66     // Return compressed line
  67     return comp_data;
  68 }
  69
  70 } // namespace Compressor
  71
  72 Compressor::CPack*
  73 CPackParams::create()
  74 {
  75     return new Compressor::CPack(this);
  76 }