src/mem/cache/compressors/cpack.cc

/*
 * Copyright (c) 2018-2019 Inria
 * All rights reserved.
 *
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 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
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 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Daniel Carvalho
 */

/** @file
 * Implementation of the CPack cache compressor.
 */

#include "mem/cache/compressors/cpack.hh"

#include "mem/cache/compressors/dictionary_compressor_impl.hh"
#include "params/CPack.hh"

CPack::CPack(const Params *p)
    : DictionaryCompressor<uint32_t>(p)
{
}

void
CPack::addToDictionary(DictionaryEntry data)
{
    assert(numEntries < dictionarySize);
    dictionary[numEntries++] = data;
}

std::unique_ptr<BaseCacheCompressor::CompressionData>
CPack::compress(const uint64_t* data, Cycles& comp_lat, Cycles& decomp_lat)
{
    std::unique_ptr<BaseCacheCompressor::CompressionData> comp_data =
        DictionaryCompressor<uint32_t>::compress(data);

    // Set compression latency (Accounts for pattern matching, length
    // generation, packaging and shifting)
    comp_lat = Cycles(blkSize/8+5);

    // Set decompression latency (1 qword per cycle)
    decomp_lat = Cycles(blkSize/8);

    // Return compressed line
    return std::move(comp_data);
}

CPack*
CPackParams::create()
{
    return new CPack(this);
}