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
40#include "cpu/pred/multiperspective_perceptron_tage_64KB.hh"
41
42MPP_StatisticalCorrector_64KB::MPP_StatisticalCorrector_64KB(
43    const MPP_StatisticalCorrector_64KBParams *p)
44  : MPP_StatisticalCorrector(p),
45    numEntriesSecondLocalHistories(p->numEntriesSecondLocalHistories),
46    numEntriesThirdLocalHistories(p->numEntriesThirdLocalHistories),
47    snb(p->snb),
48    logSnb(p->logSnb),
49    sm(p->sm),
50    tnb(p->tnb),
51    logTnb(p->logTnb),
52    tm(p->tm)
53{
54    initGEHLTable(snb, sm, sgehl, logSnb, ws, -1);
55    initGEHLTable(tnb, tm, tgehl, logTnb, wt, -1);
56}
57
58MPP_StatisticalCorrector_64KB::SCThreadHistory*
59MPP_StatisticalCorrector_64KB::makeThreadHistory()
60{
61    MPP_SCThreadHistory *sh = new MPP_SCThreadHistory();
62
63    sh->setNumOrdinalHistories(3);
64    sh->initLocalHistory(1, numEntriesFirstLocalHistories, 4);
65    sh->initLocalHistory(2, numEntriesSecondLocalHistories, 5);
66    sh->initLocalHistory(3, numEntriesThirdLocalHistories, 3);
67
68    return sh;
69}
70
71
72void
73MPP_StatisticalCorrector_64KB::getBiasLSUM(Addr branch_pc,
74        StatisticalCorrector::BranchInfo* bi, int &lsum) const
75{
76    int8_t ctr = bias[getIndBias(branch_pc, bi, false /* unused */)];
77    lsum += 2.09 * ctr;
78    ctr = biasSK[getIndBiasSK(branch_pc, bi)];
79    lsum += 2.08 * ctr;
80}
81
82int
83MPP_StatisticalCorrector_64KB::gPredictions(ThreadID tid, Addr branch_pc,
84        StatisticalCorrector::BranchInfo* bi, int & lsum, int64_t phist)
85{
86    MPP_SCThreadHistory *sh = static_cast<MPP_SCThreadHistory *>(scHistory);
87    unsigned int pc = branch_pc;
88    lsum += gPredict((pc << 1) + bi->predBeforeSC, sh->globalHist << 11,
89                      gm, ggehl, gnb, logGnb, wg);
90
91    // Local History #1
92    lsum += 2.02 * gPredict(branch_pc, sh->getLocalHistory(1, branch_pc),
93                            lm, lgehl, lnb, logLnb, wl);
94    if (sh->getLocalHistory(1, branch_pc) == 2047) lsum += 4;
95    if (sh->getLocalHistory(1, branch_pc) == 0) lsum -= 4;
96
97    // Local History #3
98    lsum += gPredict(branch_pc, sh->getLocalHistory(3, branch_pc) << 11,
99                     tm, tgehl, tnb, logTnb, wt);
100
101    // Local History #2
102    lsum += gPredict(branch_pc, sh->getLocalHistory(2, branch_pc),
103                     sm, sgehl, snb, logSnb, ws);
104
105    lsum += gPredict(branch_pc, sh->getHistoryStackEntry(),
106                     pm, pgehl, pnb, logPnb, wp);
107
108    int thres = pUpdateThreshold[getIndUpd(branch_pc)];
109
110    return thres;
111}
112
113void
114MPP_StatisticalCorrector_64KB::gUpdates(ThreadID tid, Addr pc, bool taken,
115        StatisticalCorrector::BranchInfo* bi, int64_t phist)
116{
117    MPP_SCThreadHistory *sh = static_cast<MPP_SCThreadHistory *>(scHistory);
118
119    gUpdate((pc << 1) + bi->predBeforeSC, taken, sh->globalHist << 11,
120            gm, ggehl, gnb, logGnb, wg, bi);
121
122    gUpdate(pc, taken, sh->getLocalHistory(1, pc),
123            lm, lgehl, lnb, logLnb, wl, bi);
124
125    gUpdate(pc, taken, sh->getLocalHistory(2, pc),
126            sm, sgehl, snb, logSnb, ws, bi);
127
128    gUpdate(pc, taken, sh->getLocalHistory(3, pc) << 11,
129            tm, tgehl, tnb, logTnb, wt, bi);
130
131    gUpdate(pc, taken, sh->getHistoryStackEntry(),
132            pm, pgehl, pnb, logPnb, wp, bi);
133}
134
135void
136MPP_StatisticalCorrector_64KB::scHistoryUpdate(Addr branch_pc,
137        const StaticInstPtr &inst, bool taken,
138        StatisticalCorrector::BranchInfo *bi, Addr corrTarget)
139{
140    int brtype = inst->isDirectCtrl() ? 0 : 2;
141    if (! inst->isUncondCtrl()) {
142        ++brtype;
143    }
144
145    MPP_SCThreadHistory *sh = static_cast<MPP_SCThreadHistory *>(scHistory);
146
147    if (brtype & 1) {
148        sh->globalHist = (sh->globalHist << 1) + taken;
149        sh->updateLocalHistory(2, branch_pc, taken,
150                              (branch_pc ^ (branch_pc >> 4)) & 15);
151        sh->updateLocalHistory(3, branch_pc, taken);
152    }
153    sh->updateHistoryStack(corrTarget, taken, inst->isCall(),
154                           inst->isReturn());
155
156    StatisticalCorrector::scHistoryUpdate(branch_pc, inst, taken, bi,
157                                          corrTarget);
158}
159
160size_t
161MPP_StatisticalCorrector_64KB::getSizeInBits() const
162{
163    size_t bits = 16; //global histories
164
165    bits += (1 << logSizeUp) * pUpdateThresholdWidth;
166
167    bits += scCountersWidth * 2 * (1 << logBias); //2 bias arrays
168
169    bits += (gnb - 2) * (1 << logGnb) * (scCountersWidth - 1) +
170            (1 << (logGnb - 1)) * (2 * scCountersWidth - 1);
171
172    bits += (pnb - 2) * (1 << logPnb) * (scCountersWidth - 1) +
173            (1 << (logPnb - 1)) * (2 * scCountersWidth - 1);
174
175    bits += (lnb - 2) * (1 << logLnb) * (scCountersWidth - 1) +
176            (1 << (logLnb - 1)) * (2 * scCountersWidth - 1);
177
178    bits += numEntriesFirstLocalHistories * lm[0];
179
180    bits += (snb - 2) * (1 << logSnb) * (scCountersWidth - 1) +
181            (1 << (logSnb - 1)) * (2 * scCountersWidth - 1);
182
183    bits += numEntriesSecondLocalHistories * sm[0];
184
185    bits += (tnb - 2) * (1 << logTnb) * (scCountersWidth - 1) +
186            (1 << (logTnb - 1)) * (2 * scCountersWidth - 1);
187
188    /* tm[0] is artificially increased by 11 to accomodate IMLI */
189    bits += numEntriesThirdLocalHistories * (tm[0] - 11);
190
191    bits += 16 * 16; // History stack
192    bits += 4;       // History stack pointer
193
194    bits += 3 * chooserConfWidth; // 3 chooser counters
195
196    return bits;
197}
198
199MPP_StatisticalCorrector_64KB*
200MPP_StatisticalCorrector_64KBParams::create()
201{
202    return new MPP_StatisticalCorrector_64KB(this);
203}
204
205
206MultiperspectivePerceptronTAGE64KB::MultiperspectivePerceptronTAGE64KB(
207        const MultiperspectivePerceptronTAGE64KBParams *p)
208    : MultiperspectivePerceptronTAGE(p)
209{
210}
211
212void
213MultiperspectivePerceptronTAGE64KB::createSpecs()
214{
215    addSpec(new BLURRYPATH(5, 15, -1, 2.25, 0, 6, *this));
216    addSpec(new BLURRYPATH(8, 10, -1, 2.25, 0, 6, *this));
217    addSpec(new RECENCYPOS(31, 3.5, 0, 6, *this));
218    addSpec(new GHISTMODPATH(3, 7, 1, 2.24, 0, 6, *this));
219    addSpec(new MODPATH(3, 20, 3, 2.24, 0, 6, *this));
220    addSpec(new IMLI(1, 2.23, 0, 6, *this));
221    addSpec(new IMLI(4, 1.98, 0, 6, *this));
222    addSpec(new RECENCY(9, 3, -1, 2.51, 0, 6, *this));
223    addSpec(new ACYCLIC(12, -1, -1, 2.0, 0, 6, *this));
224}
225
226MultiperspectivePerceptronTAGE64KB*
227MultiperspectivePerceptronTAGE64KBParams::create()
228{
229    return new MultiperspectivePerceptronTAGE64KB(this);
230}
231