src/mem/cache/tags/compressed_tags.cc

   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 /**
  32  * @file
  33  * Definitions of a base set associative compressed superblocks tag store.
  34  */
  35
  36 #include "mem/cache/tags/compressed_tags.hh"
  37
  38 #include "mem/cache/replacement_policies/base.hh"
  39 #include "mem/cache/tags/indexing_policies/base.hh"
  40 #include "params/CompressedTags.hh"
  41
  42 CompressedTags::CompressedTags(const Params *p)
  43     : SectorTags(p)
  44 {
  45 }
  46
  47 void
  48 CompressedTags::tagsInit()
  49 {
  50     // Create blocks and superblocks
  51     blks = std::vector<CompressionBlk>(numBlocks);
  52     superBlks = std::vector<SuperBlk>(numSectors);
  53
  54     // Initialize all blocks
  55     unsigned blk_index = 0;          // index into blks array
  56     for (unsigned superblock_index = 0; superblock_index < numSectors;
  57          superblock_index++)
  58     {
  59         // Locate next cache superblock
  60         SuperBlk* superblock = &superBlks[superblock_index];
  61
  62         // Link block to indexing policy
  63         indexingPolicy->setEntry(superblock, superblock_index);
  64
  65         // Associate a replacement data entry to the block
  66         superblock->replacementData = replacementPolicy->instantiateEntry();
  67
  68         // Initialize all blocks in this superblock
  69         superblock->blks.resize(numBlocksPerSector, nullptr);
  70         for (unsigned k = 0; k < numBlocksPerSector; ++k){
  71             // Select block within the set to be linked
  72             SectorSubBlk*& blk = superblock->blks[k];
  73
  74             // Locate next cache block
  75             blk = &blks[blk_index];
  76
  77             // Associate a data chunk to the block
  78             blk->data = &dataBlks[blkSize*blk_index];
  79
  80             // Associate superblock to this block
  81             blk->setSectorBlock(superblock);
  82
  83             // Associate the superblock replacement data to this block
  84             blk->replacementData = superblock->replacementData;
  85
  86             // Set its index and sector offset
  87             blk->setSectorOffset(k);
  88
  89             // Update block index
  90             ++blk_index;
  91         }
  92     }
  93 }
  94
  95 void
  96 CompressedTags::forEachBlk(std::function<void(CacheBlk &)> visitor)
  97 {
  98     for (CompressionBlk& blk : blks) {
  99         visitor(blk);
 100     }
 101 }
 102
 103 bool
 104 CompressedTags::anyBlk(std::function<bool(CacheBlk &)> visitor)
 105 {
 106     for (CompressionBlk& blk : blks) {
 107         if (visitor(blk)) {
 108             return true;
 109         }
 110     }
 111     return false;
 112 }
 113
 114 CompressedTags *
 115 CompressedTagsParams::create()
 116 {
 117     return new CompressedTags(this);
 118 }