compressed_tags.cc revision 13938:14f80b6b37c1 
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
42CompressedTags::CompressedTags(const Params *p)
43    : SectorTags(p)
44{
45}
46
47void
48CompressedTags::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
95void
96CompressedTags::forEachBlk(std::function<void(CacheBlk &)> visitor)
97{
98    for (CompressionBlk& blk : blks) {
99        visitor(blk);
100    }
101}
102
103bool
104CompressedTags::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
114CompressedTags *
115CompressedTagsParams::create()
116{
117    return new CompressedTags(this);
118}
119