1/** 2 * Copyright (c) 2018 Inria 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are 7 * met: redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer; 9 * redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution; 12 * neither the name of the copyright holders nor the names of its 13 * contributors may be used to endorse or promote products derived from 14 * this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * Authors: Daniel Carvalho 29 */ 30 31/** @file 32 * Implementation of a simple superblock class. Each superblock consists of a 33 * number of compressed cache blocks limited by the maximum compression factor 34 * that may or may not be present in the cache. 35 */ 36 37#include "mem/cache/tags/super_blk.hh" 38 39#include "base/logging.hh" 40 41CompressionBlk::CompressionBlk() 42 : SectorSubBlk(), _size(0), _decompressionLatency(0) 43{ 44} 45 46bool 47CompressionBlk::isCompressed() const 48{ 49 return (status & BlkCompressed) != 0; 50} 51 52void 53CompressionBlk::setCompressed() 54{ 55 status |= BlkCompressed; 56} 57 58void 59CompressionBlk::setUncompressed() 60{ 61 status &= ~BlkCompressed; 62} 63 64std::size_t 65CompressionBlk::getSizeBits() const 66{ 67 return _size; 68} 69 70void 71CompressionBlk::setSizeBits(const std::size_t size) 72{ 73 _size = size; 74} 75 76Cycles 77CompressionBlk::getDecompressionLatency() const 78{ 79 return _decompressionLatency; 80} 81 82void 83CompressionBlk::setDecompressionLatency(const Cycles lat) 84{ 85 _decompressionLatency = lat; 86} 87 88std::string 89CompressionBlk::print() const 90{ 91 return csprintf("%s compressed: %d size: %llu decompression latency: %d", 92 SectorSubBlk::print(), isCompressed(), getSizeBits(), 93 getDecompressionLatency()); 94} 95 96bool 97SuperBlk::isCompressed(const CompressionBlk* ignored_blk) const 98{ 99 for (const auto& blk : blks) { 100 if (blk->isValid() && (blk != ignored_blk)) { 101 return static_cast<CompressionBlk*>(blk)->isCompressed(); 102 } 103 } 104 105 // An invalid block is seen as compressed 106 return true; 107} 108 109bool 110SuperBlk::canCoAllocate(const std::size_t compressed_size) const 111{ 112 // Simple co-allocation function: at most numBlocksPerSector blocks that 113 // compress at least to (100/numBlocksPerSector)% of their original size 114 // can share a superblock 115 return (compressed_size <= (blkSize * 8) / blks.size()); 116} 117 118void 119SuperBlk::setBlkSize(const std::size_t blk_size) 120{ 121 assert(blkSize == 0); 122 blkSize = blk_size; 123} 124