--- /dev/null
+/*
+ * Copyright (c) 2019 Inria
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * 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
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Daniel Carvalho
+ */
+
+/** @file
+ * Implementation of a zero compressor, which compressed data if it is entirely
+ * composed of zero bits.
+ */
+
+#include "mem/cache/compressors/zero.hh"
+
+#include "debug/CacheComp.hh"
+#include "mem/cache/compressors/dictionary_compressor_impl.hh"
+#include "params/ZeroCompressor.hh"
+
+ZeroCompressor::ZeroCompressor(const Params *p)
+ : DictionaryCompressor<uint64_t>(p)
+{
+}
+
+void
+ZeroCompressor::addToDictionary(DictionaryEntry data)
+{
+ assert(numEntries < dictionarySize);
+ dictionary[numEntries++] = data;
+}
+
+std::unique_ptr<BaseCacheCompressor::CompressionData>
+ZeroCompressor::compress(const uint64_t* data, Cycles& comp_lat,
+ Cycles& decomp_lat)
+{
+ std::unique_ptr<BaseCacheCompressor::CompressionData> comp_data =
+ DictionaryCompressor::compress(data);
+
+ // If there is any non-zero entry, the compressor failed
+ if (numEntries > 0) {
+ comp_data->setSizeBits(blkSize * 8);
+ DPRINTF(CacheComp, "Zero compression failed\n");
+ }
+
+ // Set compression latency (Assumes full line zero comparison)
+ comp_lat = Cycles(1);
+
+ // Set decompression latency
+ decomp_lat = Cycles(1);
+
+ // Return compressed line
+ return comp_data;
+}
+
+ZeroCompressor*
+ZeroCompressorParams::create()
+{
+ return new ZeroCompressor(this);
+}
--- /dev/null
+/*
+ * Copyright (c) 2019 Inria
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * 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
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Daniel Carvalho
+ */
+
+/** @file
+ * Definition of a zero compressor, which compressed data if it is entirely
+ * composed of zero bits.
+ */
+
+#ifndef __MEM_CACHE_COMPRESSORS_ZERO_HH__
+#define __MEM_CACHE_COMPRESSORS_ZERO_HH__
+
+#include <array>
+#include <cstdint>
+#include <map>
+#include <memory>
+
+#include "mem/cache/compressors/dictionary_compressor.hh"
+
+struct ZeroCompressorParams;
+
+class ZeroCompressor : public DictionaryCompressor<uint64_t>
+{
+ protected:
+ using DictionaryEntry = DictionaryCompressor<uint64_t>::DictionaryEntry;
+
+ // Forward declaration of all possible patterns
+ class PatternX;
+ class PatternZ;
+
+ /**
+ * The patterns proposed in the paper. Each letter represents a byte:
+ * Z is a null byte, M is a dictionary match, X is a new value.
+ * These are used as indexes to reference the pattern data. If a new
+ * pattern is added, it must be done before NUM_PATTERNS.
+ */
+ typedef enum {
+ X, Z, NUM_PATTERNS
+ } PatternNumber;
+
+ /**
+ * Convenience factory declaration. The templates must be organized by
+ * size, with the smallest first, and "no-match" last.
+ */
+ using PatternFactory = Factory<PatternZ, PatternX>;
+
+ uint64_t getNumPatterns() const override { return NUM_PATTERNS; }
+
+ std::string
+ getName(int number) const override
+ {
+ static std::map<int, std::string> pattern_names = {
+ {X, "X"}, {Z, "Z"}
+ };
+
+ return pattern_names[number];
+ };
+
+ std::unique_ptr<Pattern>
+ getPattern(const DictionaryEntry& bytes, const DictionaryEntry& dict_bytes,
+ const int match_location) const override
+ {
+ return PatternFactory::getPattern(bytes, dict_bytes, match_location);
+ }
+
+ void addToDictionary(DictionaryEntry data) override;
+
+ std::unique_ptr<BaseCacheCompressor::CompressionData> compress(
+ const uint64_t* data, Cycles& comp_lat, Cycles& decomp_lat) override;
+
+ public:
+ typedef ZeroCompressorParams Params;
+ ZeroCompressor(const Params *p);
+ ~ZeroCompressor() = default;
+};
+
+class ZeroCompressor::PatternX
+ : public DictionaryCompressor::UncompressedPattern
+{
+ public:
+ PatternX(const DictionaryEntry bytes, const int match_location)
+ : DictionaryCompressor::UncompressedPattern(X, 0, 1, match_location,
+ bytes)
+ {
+ }
+};
+
+class ZeroCompressor::PatternZ
+ : public DictionaryCompressor::MaskedValuePattern<0, 0xFFFFFFFFFFFFFFFF>
+{
+ public:
+ PatternZ(const DictionaryEntry bytes, const int match_location)
+ : DictionaryCompressor::MaskedValuePattern<0, 0xFFFFFFFFFFFFFFFF>(
+ Z, 1, 1, match_location, bytes)
+ {
+ }
+};
+
+#endif //__MEM_CACHE_COMPRESSORS_ZERO_HH__
projects / gem5.git / commitdiff