Daniel Carvalho has submitted this change. (
https://gem5-review.googlesource.com/c/public/gem5/+/21155 )
Change subject: mem-cache: Implement a zero compressor
......................................................................
mem-cache: Implement a zero compressor
The zero compressor can only compress data composed solely of zero
bits.
Change-Id: I8b359c03776a8748abd144a178bda944b5a1b766
Signed-off-by: Daniel R. Carvalho <oda...@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/21155
Tested-by: kokoro <noreply+kok...@google.com>
Reviewed-by: Bobby R. Bruce <bbr...@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbr...@ucdavis.edu>
---
M src/mem/cache/compressors/Compressors.py
M src/mem/cache/compressors/SConscript
A src/mem/cache/compressors/zero.cc
A src/mem/cache/compressors/zero.hh
4 files changed, 212 insertions(+), 0 deletions(-)
Approvals:
Bobby R. Bruce: Looks good to me, approved; Looks good to me, approved
kokoro: Regressions pass
diff --git a/src/mem/cache/compressors/Compressors.py
b/src/mem/cache/compressors/Compressors.py
index 4db6d43..a8e51a5 100644
--- a/src/mem/cache/compressors/Compressors.py
+++ b/src/mem/cache/compressors/Compressors.py
@@ -68,3 +68,8 @@
cxx_header = "mem/cache/compressors/fpcd.hh"
dictionary_size = 2
+
+class ZeroCompressor(BaseDictionaryCompressor):
+ type = 'ZeroCompressor'
+ cxx_class = 'ZeroCompressor'
+ cxx_header = "mem/cache/compressors/zero.hh"
diff --git a/src/mem/cache/compressors/SConscript
b/src/mem/cache/compressors/SConscript
index 4df20d2..27d852d 100644
--- a/src/mem/cache/compressors/SConscript
+++ b/src/mem/cache/compressors/SConscript
@@ -37,3 +37,4 @@
Source('bdi.cc')
Source('cpack.cc')
Source('fpcd.cc')
+Source('zero.cc')
diff --git a/src/mem/cache/compressors/zero.cc
b/src/mem/cache/compressors/zero.cc
new file mode 100644
index 0000000..3fdf5f1
--- /dev/null
+++ b/src/mem/cache/compressors/zero.cc
@@ -0,0 +1,81 @@
+/*
+ * 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);
+}
diff --git a/src/mem/cache/compressors/zero.hh
b/src/mem/cache/compressors/zero.hh
new file mode 100644
index 0000000..62b3633
--- /dev/null
+++ b/src/mem/cache/compressors/zero.hh
@@ -0,0 +1,125 @@
+/*
+ * 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__
--
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Gerrit-Project: public/gem5
Gerrit-Branch: master
Gerrit-Change-Id: I8b359c03776a8748abd144a178bda944b5a1b766
Gerrit-Change-Number: 21155
Gerrit-PatchSet: 8
Gerrit-Owner: Daniel Carvalho <oda...@yahoo.com.br>
Gerrit-Reviewer: Bobby R. Bruce <bbr...@ucdavis.edu>
Gerrit-Reviewer: Daniel Carvalho <oda...@yahoo.com.br>
Gerrit-Reviewer: Jason Lowe-Power <ja...@lowepower.com>
Gerrit-Reviewer: Nikos Nikoleris <nikos.nikole...@arm.com>
Gerrit-Reviewer: kokoro <noreply+kok...@google.com>
Gerrit-MessageType: merged
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