LRUPolicy.cc revision 11061:25b53a7195f7 
1/*
2 * Copyright (c) 2013 Advanced Micro Devices, Inc
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 * Author: Derek Hower
29 */
30
31#include "mem/ruby/structures/LRUPolicy.hh"
32
33
34
35LRUPolicy::LRUPolicy(const Params * p)
36    : AbstractReplacementPolicy(p)
37{
38}
39
40
41LRUPolicy::~LRUPolicy()
42{
43}
44
45LRUPolicy *
46LRUReplacementPolicyParams::create()
47{
48    return new LRUPolicy(this);
49}
50
51
52void
53LRUPolicy::touch(int64_t set, int64_t index, Tick time)
54{
55    assert(index >= 0 && index < m_assoc);
56    assert(set >= 0 && set < m_num_sets);
57
58    m_last_ref_ptr[set][index] = time;
59}
60
61int64_t
62LRUPolicy::getVictim(int64_t set) const
63{
64    Tick time, smallest_time;
65    int64_t smallest_index = 0;
66    smallest_time = m_last_ref_ptr[set][0];
67
68    for (unsigned i = 0; i < m_assoc; i++) {
69        time = m_last_ref_ptr[set][i];
70
71        if (time < smallest_time) {
72            smallest_index = i;
73            smallest_time = time;
74        }
75    }
76
77    return smallest_index;
78}
79