gem5  v21.1.0.2
multiperspective_perceptron_tage_64KB.cc
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1 /*
2  * Copyright 2019 Texas A&M University
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are met:
6  *
7  * 1. Redistributions of source code must retain the above copyright notice,
8  * this list of conditions and the following disclaimer.
9  *
10  * 2. Redistributions in binary form must reproduce the above copyright notice,
11  * this list of conditions and the following disclaimer in the documentation
12  * and/or other materials provided with the distribution.
13  *
14  * 3. Neither the name of the copyright holder nor the names of its
15  * contributors may be used to endorse or promote products derived from this
16  * software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  *
30  * Author: Daniel A. Jiménez
31  * Adapted to gem5 by: Javier Bueno Hedo
32  *
33  */
34 
35 /*
36  * Multiperspective Perceptron Predictor with TAGE (by Daniel A. Jiménez)
37  * 64 KB version
38  */
39 
41 
42 namespace gem5
43 {
44 
45 namespace branch_prediction
46 {
47 
49  const MPP_StatisticalCorrector_64KBParams &p)
51  numEntriesSecondLocalHistories(p.numEntriesSecondLocalHistories),
52  numEntriesThirdLocalHistories(p.numEntriesThirdLocalHistories),
53  snb(p.snb),
54  logSnb(p.logSnb),
55  sm(p.sm),
56  tnb(p.tnb),
57  logTnb(p.logTnb),
58  tm(p.tm)
59 {
60  initGEHLTable(snb, sm, sgehl, logSnb, ws, -1);
61  initGEHLTable(tnb, tm, tgehl, logTnb, wt, -1);
62 }
63 
66 {
68 
69  sh->setNumOrdinalHistories(3);
70  sh->initLocalHistory(1, numEntriesFirstLocalHistories, 4);
71  sh->initLocalHistory(2, numEntriesSecondLocalHistories, 5);
72  sh->initLocalHistory(3, numEntriesThirdLocalHistories, 3);
73 
74  return sh;
75 }
76 
77 
78 void
80  StatisticalCorrector::BranchInfo* bi, int &lsum) const
81 {
82  int8_t ctr = bias[getIndBias(branch_pc, bi, false /* unused */)];
83  lsum += 2.09 * ctr;
84  ctr = biasSK[getIndBiasSK(branch_pc, bi)];
85  lsum += 2.08 * ctr;
86 }
87 
88 int
90  StatisticalCorrector::BranchInfo* bi, int & lsum, int64_t phist)
91 {
93  unsigned int pc = branch_pc;
94  lsum += gPredict((pc << 1) + bi->predBeforeSC, sh->globalHist << 11,
95  gm, ggehl, gnb, logGnb, wg);
96 
97  // Local History #1
98  lsum += 2.02 * gPredict(branch_pc, sh->getLocalHistory(1, branch_pc),
99  lm, lgehl, lnb, logLnb, wl);
100  if (sh->getLocalHistory(1, branch_pc) == 2047) lsum += 4;
101  if (sh->getLocalHistory(1, branch_pc) == 0) lsum -= 4;
102 
103  // Local History #3
104  lsum += gPredict(branch_pc, sh->getLocalHistory(3, branch_pc) << 11,
105  tm, tgehl, tnb, logTnb, wt);
106 
107  // Local History #2
108  lsum += gPredict(branch_pc, sh->getLocalHistory(2, branch_pc),
109  sm, sgehl, snb, logSnb, ws);
110 
111  lsum += gPredict(branch_pc, sh->getHistoryStackEntry(),
112  pm, pgehl, pnb, logPnb, wp);
113 
114  int thres = pUpdateThreshold[getIndUpd(branch_pc)];
115 
116  return thres;
117 }
118 
119 void
121  StatisticalCorrector::BranchInfo* bi, int64_t phist)
122 {
124 
125  gUpdate((pc << 1) + bi->predBeforeSC, taken, sh->globalHist << 11,
126  gm, ggehl, gnb, logGnb, wg, bi);
127 
128  gUpdate(pc, taken, sh->getLocalHistory(1, pc),
129  lm, lgehl, lnb, logLnb, wl, bi);
130 
131  gUpdate(pc, taken, sh->getLocalHistory(2, pc),
132  sm, sgehl, snb, logSnb, ws, bi);
133 
134  gUpdate(pc, taken, sh->getLocalHistory(3, pc) << 11,
135  tm, tgehl, tnb, logTnb, wt, bi);
136 
137  gUpdate(pc, taken, sh->getHistoryStackEntry(),
138  pm, pgehl, pnb, logPnb, wp, bi);
139 }
140 
141 void
143  const StaticInstPtr &inst, bool taken,
145 {
146  int brtype = inst->isDirectCtrl() ? 0 : 2;
147  if (! inst->isUncondCtrl()) {
148  ++brtype;
149  }
150 
152 
153  if (brtype & 1) {
154  sh->globalHist = (sh->globalHist << 1) + taken;
155  sh->updateLocalHistory(2, branch_pc, taken,
156  (branch_pc ^ (branch_pc >> 4)) & 15);
157  sh->updateLocalHistory(3, branch_pc, taken);
158  }
159  sh->updateHistoryStack(corrTarget, taken, inst->isCall(),
160  inst->isReturn());
161 
162  StatisticalCorrector::scHistoryUpdate(branch_pc, inst, taken, bi,
163  corrTarget);
164 }
165 
166 size_t
168 {
169  size_t bits = 16; //global histories
170 
172 
173  bits += scCountersWidth * 2 * (1 << logBias); //2 bias arrays
174 
175  bits += (gnb - 2) * (1 << logGnb) * (scCountersWidth - 1) +
176  (1 << (logGnb - 1)) * (2 * scCountersWidth - 1);
177 
178  bits += (pnb - 2) * (1 << logPnb) * (scCountersWidth - 1) +
179  (1 << (logPnb - 1)) * (2 * scCountersWidth - 1);
180 
181  bits += (lnb - 2) * (1 << logLnb) * (scCountersWidth - 1) +
182  (1 << (logLnb - 1)) * (2 * scCountersWidth - 1);
183 
185 
186  bits += (snb - 2) * (1 << logSnb) * (scCountersWidth - 1) +
187  (1 << (logSnb - 1)) * (2 * scCountersWidth - 1);
188 
190 
191  bits += (tnb - 2) * (1 << logTnb) * (scCountersWidth - 1) +
192  (1 << (logTnb - 1)) * (2 * scCountersWidth - 1);
193 
194  /* tm[0] is artificially increased by 11 to accomodate IMLI */
195  bits += numEntriesThirdLocalHistories * (tm[0] - 11);
196 
197  bits += 16 * 16; // History stack
198  bits += 4; // History stack pointer
199 
200  bits += 3 * chooserConfWidth; // 3 chooser counters
201 
202  return bits;
203 }
204 
206  const MultiperspectivePerceptronTAGE64KBParams &p)
208 {
209 }
210 
211 void
213 {
214  addSpec(new BLURRYPATH(5, 15, -1, 2.25, 0, 6, *this));
215  addSpec(new BLURRYPATH(8, 10, -1, 2.25, 0, 6, *this));
216  addSpec(new RECENCYPOS(31, 3.5, 0, 6, *this));
217  addSpec(new GHISTMODPATH(3, 7, 1, 2.24, 0, 6, *this));
218  addSpec(new MODPATH(3, 20, 3, 2.24, 0, 6, *this));
219  addSpec(new IMLI(1, 2.23, 0, 6, *this));
220  addSpec(new IMLI(4, 1.98, 0, 6, *this));
221  addSpec(new RECENCY(9, 3, -1, 2.51, 0, 6, *this));
222  addSpec(new ACYCLIC(12, -1, -1, 2.0, 0, 6, *this));
223 }
224 
225 } // namespace branch_prediction
226 } // namespace gem5
gem5::branch_prediction::StatisticalCorrector::scHistory
SCThreadHistory * scHistory
Definition: statistical_corrector.hh:139
gem5::branch_prediction::StatisticalCorrector::scHistoryUpdate
virtual void scHistoryUpdate(Addr branch_pc, const StaticInstPtr &inst, bool taken, BranchInfo *tage_bi, Addr corrTarget)
Definition: statistical_corrector.cc:295
gem5::branch_prediction::StatisticalCorrector::lm
std::vector< int > lm
Definition: statistical_corrector.hh:158
gem5::branch_prediction::MPP_StatisticalCorrector::getIndBias
unsigned getIndBias(Addr branch_pc, StatisticalCorrector::BranchInfo *bi, bool bias) const override
Definition: multiperspective_perceptron_tage.cc:291
gem5::branch_prediction::MultiperspectivePerceptron::GHISTMODPATH
Definition: multiperspective_perceptron.hh:877
gem5::branch_prediction::StatisticalCorrector::biasSK
std::vector< int8_t > biasSK
Definition: statistical_corrector.hh:170
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::logSnb
const unsigned logSnb
Definition: multiperspective_perceptron_tage_64KB.hh:59
gem5::branch_prediction::StatisticalCorrector::wl
std::vector< int8_t > wl
Definition: statistical_corrector.hh:160
gem5::branch_prediction::MPP_StatisticalCorrector::logGnb
const unsigned logGnb
Definition: multiperspective_perceptron_tage.hh:116
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::logTnb
const unsigned logTnb
Definition: multiperspective_perceptron_tage_64KB.hh:66
gem5::branch_prediction::MultiperspectivePerceptronTAGE64KB::MultiperspectivePerceptronTAGE64KB
MultiperspectivePerceptronTAGE64KB(const MultiperspectivePerceptronTAGE64KBParams &p)
Definition: multiperspective_perceptron_tage_64KB.cc:205
gem5::branch_prediction::MultiperspectivePerceptron::ACYCLIC
Definition: multiperspective_perceptron.hh:546
gem5::branch_prediction::MultiperspectivePerceptron::addSpec
void addSpec(HistorySpec *spec)
Add a table spec to the prefetcher.
Definition: multiperspective_perceptron.hh:487
gem5::branch_prediction::MultiperspectivePerceptron::MODPATH
Definition: multiperspective_perceptron.hh:776
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::wt
std::vector< int8_t > wt
Definition: multiperspective_perceptron_tage_64KB.hh:69
gem5::branch_prediction::StatisticalCorrector::lnb
const unsigned lnb
Definition: statistical_corrector.hh:156
gem5::branch_prediction::StatisticalCorrector::initGEHLTable
void initGEHLTable(unsigned numLenghts, std::vector< int > lengths, std::vector< int8_t > *&table, unsigned logNumEntries, std::vector< int8_t > &w, int8_t wInitValue)
Definition: statistical_corrector.cc:134
gem5::PowerISA::bi
Bitfield< 20, 16 > bi
Definition: types.hh:80
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::ws
std::vector< int8_t > ws
Definition: multiperspective_perceptron_tage_64KB.hh:62
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::numEntriesSecondLocalHistories
const unsigned numEntriesSecondLocalHistories
Definition: multiperspective_perceptron_tage_64KB.hh:54
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::numEntriesThirdLocalHistories
const unsigned numEntriesThirdLocalHistories
Definition: multiperspective_perceptron_tage_64KB.hh:55
gem5::RefCountingPtr< StaticInst >
gem5::branch_prediction::MPP_StatisticalCorrector
Definition: multiperspective_perceptron_tage.hh:103
gem5::branch_prediction::MPP_StatisticalCorrector::gnb
const unsigned gnb
Definition: multiperspective_perceptron_tage.hh:115
gem5::StaticInst::isReturn
bool isReturn() const
Definition: static_inst.hh:184
gem5::branch_prediction::MPP_StatisticalCorrector::getIndBiasSK
unsigned getIndBiasSK(Addr branch_pc, StatisticalCorrector::BranchInfo *bi) const override
Definition: multiperspective_perceptron_tage.cc:299
gem5::branch_prediction::StatisticalCorrector::logSizeUp
const unsigned logSizeUp
Definition: statistical_corrector.hh:143
gem5::branch_prediction::StatisticalCorrector::logBias
const unsigned logBias
Definition: statistical_corrector.hh:141
gem5::branch_prediction::MPP_StatisticalCorrector::wg
std::vector< int8_t > wg
Definition: multiperspective_perceptron_tage.hh:119
gem5::branch_prediction::StatisticalCorrector::scCountersWidth
const unsigned scCountersWidth
Definition: statistical_corrector.hh:187
gem5::MipsISA::p
Bitfield< 0 > p
Definition: pra_constants.hh:326
gem5::branch_prediction::StatisticalCorrector::pUpdateThreshold
std::vector< int > pUpdateThreshold
Definition: statistical_corrector.hh:176
gem5::branch_prediction::StatisticalCorrector::numEntriesFirstLocalHistories
const unsigned numEntriesFirstLocalHistories
Definition: statistical_corrector.hh:146
gem5::branch_prediction::StatisticalCorrector::pUpdateThresholdWidth
const unsigned pUpdateThresholdWidth
Definition: statistical_corrector.hh:183
gem5::branch_prediction::MultiperspectivePerceptron::IMLI
Definition: multiperspective_perceptron.hh:684
gem5::branch_prediction::MultiperspectivePerceptronTAGE64KB::createSpecs
void createSpecs() override
Creates the tables of the predictor.
Definition: multiperspective_perceptron_tage_64KB.cc:212
gem5::bits
constexpr T bits(T val, unsigned first, unsigned last)
Extract the bitfield from position 'first' to 'last' (inclusive) from 'val' and right justify it.
Definition: bitfield.hh:76
multiperspective_perceptron_tage_64KB.hh
gem5::StaticInst::isDirectCtrl
bool isDirectCtrl() const
Definition: static_inst.hh:185
gem5::branch_prediction::MPP_StatisticalCorrector::gm
std::vector< int > gm
Definition: multiperspective_perceptron_tage.hh:117
gem5::PowerISA::tm
Bitfield< 32 > tm
Definition: misc.hh:107
gem5::Addr
uint64_t Addr
Address type This will probably be moved somewhere else in the near future.
Definition: types.hh:147
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::tm
std::vector< int > tm
Definition: multiperspective_perceptron_tage_64KB.hh:67
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::gUpdates
void gUpdates(ThreadID tid, Addr pc, bool taken, StatisticalCorrector::BranchInfo *bi, int64_t phist) override
Definition: multiperspective_perceptron_tage_64KB.cc:120
gem5::branch_prediction::StatisticalCorrector::BranchInfo
Definition: statistical_corrector.hh:200
gem5::branch_prediction::MPP_StatisticalCorrector::pnb
const unsigned pnb
Definition: multiperspective_perceptron_tage.hh:108
gem5::ArmISA::sh
Bitfield< 8, 7 > sh
Definition: misc_types.hh:660
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::getBiasLSUM
void getBiasLSUM(Addr branch_pc, StatisticalCorrector::BranchInfo *bi, int &lsum) const override
Definition: multiperspective_perceptron_tage_64KB.cc:79
gem5::branch_prediction::MPP_StatisticalCorrector::pm
std::vector< int > pm
Definition: multiperspective_perceptron_tage.hh:110
gem5::branch_prediction::StatisticalCorrector::lgehl
std::vector< int8_t > * lgehl
Definition: statistical_corrector.hh:159
gem5::branch_prediction::MPP_StatisticalCorrector::getIndUpd
unsigned getIndUpd(Addr branch_pc) const override
Definition: multiperspective_perceptron_tage.cc:320
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::gPredictions
int gPredictions(ThreadID tid, Addr branch_pc, StatisticalCorrector::BranchInfo *bi, int &lsum, int64_t phist) override
Definition: multiperspective_perceptron_tage_64KB.cc:89
gem5::branch_prediction::MPP_StatisticalCorrector::ggehl
std::vector< int8_t > * ggehl
Definition: multiperspective_perceptron_tage.hh:118
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::sm
std::vector< int > sm
Definition: multiperspective_perceptron_tage_64KB.hh:60
gem5::branch_prediction::MPP_StatisticalCorrector::wp
std::vector< int8_t > wp
Definition: multiperspective_perceptron_tage.hh:112
gem5::branch_prediction::MultiperspectivePerceptron::RECENCYPOS
Definition: multiperspective_perceptron.hh:957
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::makeThreadHistory
StatisticalCorrector::SCThreadHistory * makeThreadHistory() override
Definition: multiperspective_perceptron_tage_64KB.cc:65
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::tgehl
std::vector< int8_t > * tgehl
Definition: multiperspective_perceptron_tage_64KB.hh:68
gem5::branch_prediction::MPP_StatisticalCorrector::MPP_SCThreadHistory
Definition: multiperspective_perceptron_tage.hh:121
gem5::branch_prediction::StatisticalCorrector::bias
std::vector< int8_t > bias
Definition: statistical_corrector.hh:169
gem5::branch_prediction::MultiperspectivePerceptronTAGE
Definition: multiperspective_perceptron_tage.hh:193
gem5::MipsISA::pc
Bitfield< 4 > pc
Definition: pra_constants.hh:243
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::sgehl
std::vector< int8_t > * sgehl
Definition: multiperspective_perceptron_tage_64KB.hh:61
gem5::StaticInst::isCall
bool isCall() const
Definition: static_inst.hh:183
gem5::branch_prediction::MPP_StatisticalCorrector::gUpdate
void gUpdate(Addr branch_pc, bool taken, int64_t hist, std::vector< int > &length, std::vector< int8_t > *tab, int nbr, int logs, std::vector< int8_t > &w, StatisticalCorrector::BranchInfo *bi) override
Definition: multiperspective_perceptron_tage.cc:326
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::getSizeInBits
size_t getSizeInBits() const override
Definition: multiperspective_perceptron_tage_64KB.cc:167
gem5::branch_prediction::StatisticalCorrector::SCThreadHistory
Definition: statistical_corrector.hh:75
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::tnb
const unsigned tnb
Definition: multiperspective_perceptron_tage_64KB.hh:65
gem5::branch_prediction::StatisticalCorrector::logLnb
const unsigned logLnb
Definition: statistical_corrector.hh:157
gem5::StaticInst::isUncondCtrl
bool isUncondCtrl() const
Definition: static_inst.hh:188
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::scHistoryUpdate
void scHistoryUpdate(Addr branch_pc, const StaticInstPtr &inst, bool taken, StatisticalCorrector::BranchInfo *bi, Addr corrTarget) override
Definition: multiperspective_perceptron_tage_64KB.cc:142
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::MPP_StatisticalCorrector_64KB
MPP_StatisticalCorrector_64KB(const MPP_StatisticalCorrector_64KBParams &p)
Definition: multiperspective_perceptron_tage_64KB.cc:48
gem5::branch_prediction::MPP_StatisticalCorrector::logPnb
const unsigned logPnb
Definition: multiperspective_perceptron_tage.hh:109
gem5
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Definition: decoder.cc:40
gem5::branch_prediction::MultiperspectivePerceptron::RECENCY
Definition: multiperspective_perceptron.hh:641
gem5::branch_prediction::MPP_StatisticalCorrector_64KB::snb
const unsigned snb
Definition: multiperspective_perceptron_tage_64KB.hh:58
gem5::branch_prediction::MultiperspectivePerceptron::BLURRYPATH
Definition: multiperspective_perceptron.hh:910
gem5::branch_prediction::MPP_StatisticalCorrector::pgehl
std::vector< int8_t > * pgehl
Definition: multiperspective_perceptron_tage.hh:111
gem5::branch_prediction::StatisticalCorrector::chooserConfWidth
const unsigned chooserConfWidth
Definition: statistical_corrector.hh:180
gem5::MipsISA::sm
Bitfield< 1 > sm
Definition: pra_constants.hh:273
gem5::branch_prediction::StatisticalCorrector::gPredict
int gPredict(Addr branch_pc, int64_t hist, std::vector< int > &length, std::vector< int8_t > *tab, int nbr, int logs, std::vector< int8_t > &w)
Definition: statistical_corrector.cc:193
gem5::ThreadID
int16_t ThreadID
Thread index/ID type.
Definition: types.hh:242

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