| /* |
| * Copyright (c) 2019-2020 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. |
| */ |
| |
| /** @file |
| * Implementation of a base delta immediate compressor. @see BDI |
| */ |
| |
| #ifndef __MEM_CACHE_COMPRESSORS_BASE_DELTA_IMPL_HH__ |
| #define __MEM_CACHE_COMPRESSORS_BASE_DELTA_IMPL_HH__ |
| |
| #include "debug/CacheComp.hh" |
| #include "mem/cache/compressors/base_delta.hh" |
| #include "mem/cache/compressors/dictionary_compressor_impl.hh" |
| |
| namespace Compressor { |
| |
| template <class BaseType, std::size_t DeltaSizeBits> |
| BaseDelta<BaseType, DeltaSizeBits>::BaseDelta(const Params &p) |
| : DictionaryCompressor<BaseType>(p) |
| { |
| } |
| |
| template <class BaseType, std::size_t DeltaSizeBits> |
| void |
| BaseDelta<BaseType, DeltaSizeBits>::resetDictionary() |
| { |
| DictionaryCompressor<BaseType>::resetDictionary(); |
| |
| // Add zero base for the immediate values |
| addToDictionary(DictionaryCompressor<BaseType>::toDictionaryEntry(0)); |
| } |
| |
| template <class BaseType, std::size_t DeltaSizeBits> |
| void |
| BaseDelta<BaseType, DeltaSizeBits>::addToDictionary(DictionaryEntry data) |
| { |
| assert(DictionaryCompressor<BaseType>::numEntries < |
| DictionaryCompressor<BaseType>::dictionarySize); |
| DictionaryCompressor<BaseType>::dictionary[ |
| DictionaryCompressor<BaseType>::numEntries++] = data; |
| } |
| |
| template <class BaseType, std::size_t DeltaSizeBits> |
| std::unique_ptr<Base::CompressionData> |
| BaseDelta<BaseType, DeltaSizeBits>::compress( |
| const std::vector<Base::Chunk>& chunks, Cycles& comp_lat, |
| Cycles& decomp_lat) |
| { |
| std::unique_ptr<Base::CompressionData> comp_data = |
| DictionaryCompressor<BaseType>::compress(chunks); |
| |
| // If there are more bases than the maximum, the compressor failed. |
| // Otherwise, we have to take into account all bases that have not |
| // been used, considering that there is an implicit zero base that |
| // does not need to be added to the final size. |
| const int diff = DEFAULT_MAX_NUM_BASES - |
| DictionaryCompressor<BaseType>::numEntries; |
| if (diff < 0) { |
| comp_data->setSizeBits(DictionaryCompressor<BaseType>::blkSize * 8); |
| DPRINTF(CacheComp, "Base%dDelta%d compression failed\n", |
| 8 * sizeof(BaseType), DeltaSizeBits); |
| } else if (diff > 0) { |
| comp_data->setSizeBits(comp_data->getSizeBits() + |
| 8 * sizeof(BaseType) * diff); |
| } |
| |
| // Set compression latency (Assumes 1 cycle per entry and 1 cycle for |
| // packing) |
| comp_lat = Cycles(1 + (DictionaryCompressor<BaseType>::blkSize / |
| sizeof(BaseType))); |
| |
| // Set decompression latency |
| decomp_lat = Cycles(1); |
| |
| // Return compressed line |
| return comp_data; |
| } |
| |
| } // namespace Compressor |
| |
| #endif //__MEM_CACHE_COMPRESSORS_BASE_DELTA_IMPL_HH__ |