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#include "mem/cache/replacement_policies/fifo_rp.hh"
32
33#include <cassert>
34#include <memory>
35
36#include "params/FIFORP.hh"
37
38FIFORP::FIFORP(const Params *p)
39    : BaseReplacementPolicy(p)
40{
41}
42
43void
44FIFORP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
45const
46{
47    // Reset insertion tick
48    std::static_pointer_cast<FIFOReplData>(
49        replacement_data)->tickInserted = Tick(0);
50}
51
52void
53FIFORP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const
54{
55    // A touch does not modify the insertion tick
56}
57
58void
59FIFORP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const
60{
61    // Set insertion tick
62    std::static_pointer_cast<FIFOReplData>(
63        replacement_data)->tickInserted = curTick();
64}
65
66ReplaceableEntry*
67FIFORP::getVictim(const ReplacementCandidates& candidates) const
68{
69    // There must be at least one replacement candidate
70    assert(candidates.size() > 0);
71
72    // Visit all candidates to find victim
73    ReplaceableEntry* victim = candidates[0];
74    for (const auto& candidate : candidates) {
75        // Update victim entry if necessary
76        if (std::static_pointer_cast<FIFOReplData>(
77                    candidate->replacementData)->tickInserted <
78                std::static_pointer_cast<FIFOReplData>(
79                    victim->replacementData)->tickInserted) {
80            victim = candidate;
81        }
82    }
83
84    return victim;
85}
86
87std::shared_ptr<ReplacementData>
88FIFORP::instantiateEntry()
89{
90    return std::shared_ptr<ReplacementData>(new FIFOReplData());
91}
92
93FIFORP*
94FIFORPParams::create()
95{
96    return new FIFORP(this);
97}
98