| /** |
| * Copyright (c) 2018 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 simple superblock class. Each superblock consists of a |
| * number of compressed cache blocks limited by the maximum compression factor |
| * that may or may not be present in the cache. |
| */ |
| |
| #include "mem/cache/tags/super_blk.hh" |
| |
| #include "base/logging.hh" |
| |
| CompressionBlk::CompressionBlk() |
| : SectorSubBlk(), _size(0), _decompressionLatency(0) |
| { |
| } |
| |
| bool |
| CompressionBlk::isCompressed() const |
| { |
| return (status & BlkCompressed) != 0; |
| } |
| |
| void |
| CompressionBlk::setCompressed() |
| { |
| status |= BlkCompressed; |
| } |
| |
| void |
| CompressionBlk::setUncompressed() |
| { |
| status &= ~BlkCompressed; |
| } |
| |
| std::size_t |
| CompressionBlk::getSizeBits() const |
| { |
| return _size; |
| } |
| |
| void |
| CompressionBlk::setSizeBits(const std::size_t size) |
| { |
| _size = size; |
| } |
| |
| Cycles |
| CompressionBlk::getDecompressionLatency() const |
| { |
| return _decompressionLatency; |
| } |
| |
| void |
| CompressionBlk::setDecompressionLatency(const Cycles lat) |
| { |
| _decompressionLatency = lat; |
| } |
| |
| std::string |
| CompressionBlk::print() const |
| { |
| return csprintf("%s compressed: %d size: %llu decompression latency: %d", |
| SectorSubBlk::print(), isCompressed(), getSizeBits(), |
| getDecompressionLatency()); |
| } |
| |
| bool |
| SuperBlk::isCompressed(const CompressionBlk* ignored_blk) const |
| { |
| for (const auto& blk : blks) { |
| if (blk->isValid() && (blk != ignored_blk)) { |
| return static_cast<CompressionBlk*>(blk)->isCompressed(); |
| } |
| } |
| |
| // An invalid block is seen as compressed |
| return true; |
| } |
| |
| bool |
| SuperBlk::canCoAllocate(const std::size_t compressed_size) const |
| { |
| // Simple co-allocation function: at most numBlocksPerSector blocks that |
| // compress at least to (100/numBlocksPerSector)% of their original size |
| // can share a superblock |
| return (compressed_size <= (blkSize * 8) / blks.size()); |
| } |
| |
| void |
| SuperBlk::setBlkSize(const std::size_t blk_size) |
| { |
| assert(blkSize == 0); |
| blkSize = blk_size; |
| } |