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/brrip_rp.hh"
32
| 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/brrip_rp.hh"
32
|
37
38BRRIPRP::BRRIPRP(const Params *p)
39 : BaseReplacementPolicy(p),
40 maxRRPV(p->max_RRPV), hitPriority(p->hit_priority), btp(p->btp)
41{
42 fatal_if(maxRRPV <= 0, "max_RRPV should be greater than zero.\n");
43}
44
45void
46BRRIPRP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
47const
48{
49 std::shared_ptr<BRRIPReplData> casted_replacement_data =
50 std::static_pointer_cast<BRRIPReplData>(replacement_data);
51
52 // Set RRPV to an invalid distance
53 casted_replacement_data->rrpv = maxRRPV + 1;
54}
55
56void
57BRRIPRP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const
58{
59 std::shared_ptr<BRRIPReplData> casted_replacement_data =
60 std::static_pointer_cast<BRRIPReplData>(replacement_data);
61
62 // Update RRPV if not 0 yet
63 // Every hit in HP mode makes the entry the last to be evicted, while
64 // in FP mode a hit makes the entry less likely to be evicted
65 if (hitPriority) {
66 casted_replacement_data->rrpv = 0;
67 } else if (casted_replacement_data->rrpv > 0) {
68 casted_replacement_data->rrpv--;
69 }
70}
71
72void
73BRRIPRP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const
74{
75 std::shared_ptr<BRRIPReplData> casted_replacement_data =
76 std::static_pointer_cast<BRRIPReplData>(replacement_data);
77
78 // Reset RRPV
79 // Replacement data is inserted as "long re-reference" if lower than btp,
80 // "distant re-reference" otherwise
81 if (random_mt.random<unsigned>(1, 100) <= btp) {
82 casted_replacement_data->rrpv = maxRRPV-1;
83 } else {
84 casted_replacement_data->rrpv = maxRRPV;
85 }
86}
87
88ReplaceableEntry*
89BRRIPRP::getVictim(const ReplacementCandidates& candidates) const
90{
91 // There must be at least one replacement candidate
92 assert(candidates.size() > 0);
93
94 // Use first candidate as dummy victim
95 ReplaceableEntry* victim = candidates[0];
96
97 // Store victim->rrpv in a variable to improve code readability
98 int victim_RRPV = std::static_pointer_cast<BRRIPReplData>(
99 victim->replacementData)->rrpv;
100
101 // Visit all candidates to find victim
102 for (const auto& candidate : candidates) {
103 // Get candidate's rrpv
104 int candidate_RRPV = std::static_pointer_cast<BRRIPReplData>(
105 candidate->replacementData)->rrpv;
106
107 // Stop searching for victims if an invalid entry is found
108 if (candidate_RRPV == maxRRPV + 1) {
109 return candidate;
110 // Update victim entry if necessary
111 } else if (candidate_RRPV > victim_RRPV) {
112 victim = candidate;
113 victim_RRPV = candidate_RRPV;
114 }
115 }
116
117 // Get difference of victim's RRPV to the highest possible RRPV in
118 // order to update the RRPV of all the other entries accordingly
119 int diff = maxRRPV - victim_RRPV;
120
121 // No need to update RRPV if there is no difference
122 if (diff > 0){
123 // Update RRPV of all candidates
124 for (const auto& candidate : candidates) {
125 std::static_pointer_cast<BRRIPReplData>(
126 candidate->replacementData)->rrpv += diff;
127 }
128 }
129
130 return victim;
131}
132
133std::shared_ptr<ReplacementData>
134BRRIPRP::instantiateEntry()
135{
136 return std::shared_ptr<ReplacementData>(new BRRIPReplData(maxRRPV));
137}
138
139BRRIPRP*
140BRRIPRPParams::create()
141{
142 return new BRRIPRP(this);
143}
| 39
40BRRIPRP::BRRIPRP(const Params *p)
41 : BaseReplacementPolicy(p),
42 maxRRPV(p->max_RRPV), hitPriority(p->hit_priority), btp(p->btp)
43{
44 fatal_if(maxRRPV <= 0, "max_RRPV should be greater than zero.\n");
45}
46
47void
48BRRIPRP::invalidate(const std::shared_ptr<ReplacementData>& replacement_data)
49const
50{
51 std::shared_ptr<BRRIPReplData> casted_replacement_data =
52 std::static_pointer_cast<BRRIPReplData>(replacement_data);
53
54 // Set RRPV to an invalid distance
55 casted_replacement_data->rrpv = maxRRPV + 1;
56}
57
58void
59BRRIPRP::touch(const std::shared_ptr<ReplacementData>& replacement_data) const
60{
61 std::shared_ptr<BRRIPReplData> casted_replacement_data =
62 std::static_pointer_cast<BRRIPReplData>(replacement_data);
63
64 // Update RRPV if not 0 yet
65 // Every hit in HP mode makes the entry the last to be evicted, while
66 // in FP mode a hit makes the entry less likely to be evicted
67 if (hitPriority) {
68 casted_replacement_data->rrpv = 0;
69 } else if (casted_replacement_data->rrpv > 0) {
70 casted_replacement_data->rrpv--;
71 }
72}
73
74void
75BRRIPRP::reset(const std::shared_ptr<ReplacementData>& replacement_data) const
76{
77 std::shared_ptr<BRRIPReplData> casted_replacement_data =
78 std::static_pointer_cast<BRRIPReplData>(replacement_data);
79
80 // Reset RRPV
81 // Replacement data is inserted as "long re-reference" if lower than btp,
82 // "distant re-reference" otherwise
83 if (random_mt.random<unsigned>(1, 100) <= btp) {
84 casted_replacement_data->rrpv = maxRRPV-1;
85 } else {
86 casted_replacement_data->rrpv = maxRRPV;
87 }
88}
89
90ReplaceableEntry*
91BRRIPRP::getVictim(const ReplacementCandidates& candidates) const
92{
93 // There must be at least one replacement candidate
94 assert(candidates.size() > 0);
95
96 // Use first candidate as dummy victim
97 ReplaceableEntry* victim = candidates[0];
98
99 // Store victim->rrpv in a variable to improve code readability
100 int victim_RRPV = std::static_pointer_cast<BRRIPReplData>(
101 victim->replacementData)->rrpv;
102
103 // Visit all candidates to find victim
104 for (const auto& candidate : candidates) {
105 // Get candidate's rrpv
106 int candidate_RRPV = std::static_pointer_cast<BRRIPReplData>(
107 candidate->replacementData)->rrpv;
108
109 // Stop searching for victims if an invalid entry is found
110 if (candidate_RRPV == maxRRPV + 1) {
111 return candidate;
112 // Update victim entry if necessary
113 } else if (candidate_RRPV > victim_RRPV) {
114 victim = candidate;
115 victim_RRPV = candidate_RRPV;
116 }
117 }
118
119 // Get difference of victim's RRPV to the highest possible RRPV in
120 // order to update the RRPV of all the other entries accordingly
121 int diff = maxRRPV - victim_RRPV;
122
123 // No need to update RRPV if there is no difference
124 if (diff > 0){
125 // Update RRPV of all candidates
126 for (const auto& candidate : candidates) {
127 std::static_pointer_cast<BRRIPReplData>(
128 candidate->replacementData)->rrpv += diff;
129 }
130 }
131
132 return victim;
133}
134
135std::shared_ptr<ReplacementData>
136BRRIPRP::instantiateEntry()
137{
138 return std::shared_ptr<ReplacementData>(new BRRIPReplData(maxRRPV));
139}
140
141BRRIPRP*
142BRRIPRPParams::create()
143{
144 return new BRRIPRP(this);
145}
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