src/cpu/pred/multiperspective_perceptron_tage_64KB.cc - public/gem5 - Git at Google

 /*
  * Copyright 2019 Texas A&M University
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright notice,
  *    this list of conditions and the following disclaimer.
  *
  * 2. Redistributions in binary form must reproduce the above copyright notice,
  *    this list of conditions and the following disclaimer in the documentation
  *    and/or other materials provided with the distribution.
  *
  * 3. Neither the name of the copyright holder nor the names of its
  *    contributors may be used to endorse or promote products derived from this
  *    software without specific prior written permission.
  *
  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  *  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  *  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  *  A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  *  HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  *  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  *  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  *  THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  *  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  *  Author: Daniel A. Jiménez
  *  Adapted to gem5 by: Javier Bueno Hedo
  *
  */

 /*
  * Multiperspective Perceptron Predictor with TAGE (by Daniel A. Jiménez)
  * 64 KB version
  */

 #include "cpu/pred/multiperspective_perceptron_tage_64KB.hh"

 namespace gem5
 {

 namespace branch_prediction
 {

 MPP_StatisticalCorrector_64KB::MPP_StatisticalCorrector_64KB(
     const MPP_StatisticalCorrector_64KBParams &p)
   : MPP_StatisticalCorrector(p),
     numEntriesSecondLocalHistories(p.numEntriesSecondLocalHistories),
     numEntriesThirdLocalHistories(p.numEntriesThirdLocalHistories),
     snb(p.snb),
     logSnb(p.logSnb),
     sm(p.sm),
     tnb(p.tnb),
     logTnb(p.logTnb),
     tm(p.tm)
 {
     initGEHLTable(snb, sm, sgehl, logSnb, ws, -1);
     initGEHLTable(tnb, tm, tgehl, logTnb, wt, -1);
 }

 MPP_StatisticalCorrector_64KB::SCThreadHistory*
 MPP_StatisticalCorrector_64KB::makeThreadHistory()
 {
     MPP_SCThreadHistory *sh = new MPP_SCThreadHistory();

     sh->setNumOrdinalHistories(3);
     sh->initLocalHistory(1, numEntriesFirstLocalHistories, 4);
     sh->initLocalHistory(2, numEntriesSecondLocalHistories, 5);
     sh->initLocalHistory(3, numEntriesThirdLocalHistories, 3);

     return sh;
 }


 void
 MPP_StatisticalCorrector_64KB::getBiasLSUM(Addr branch_pc,
         StatisticalCorrector::BranchInfo* bi, int &lsum) const
 {
     int8_t ctr = bias[getIndBias(branch_pc, bi, false /* unused */)];
     lsum += 2.09 * ctr;
     ctr = biasSK[getIndBiasSK(branch_pc, bi)];
     lsum += 2.08 * ctr;
 }

 int
 MPP_StatisticalCorrector_64KB::gPredictions(ThreadID tid, Addr branch_pc,
         StatisticalCorrector::BranchInfo* bi, int & lsum, int64_t phist)
 {
     MPP_SCThreadHistory *sh = static_cast<MPP_SCThreadHistory *>(scHistory);
     unsigned int pc = branch_pc;
     lsum += gPredict((pc << 1) + bi->predBeforeSC, sh->globalHist << 11,
                       gm, ggehl, gnb, logGnb, wg);

     // Local History #1
     lsum += 2.02 * gPredict(branch_pc, sh->getLocalHistory(1, branch_pc),
                             lm, lgehl, lnb, logLnb, wl);
     if (sh->getLocalHistory(1, branch_pc) == 2047) lsum += 4;
     if (sh->getLocalHistory(1, branch_pc) == 0) lsum -= 4;

     // Local History #3
     lsum += gPredict(branch_pc, sh->getLocalHistory(3, branch_pc) << 11,
                      tm, tgehl, tnb, logTnb, wt);

     // Local History #2
     lsum += gPredict(branch_pc, sh->getLocalHistory(2, branch_pc),
                      sm, sgehl, snb, logSnb, ws);

     lsum += gPredict(branch_pc, sh->getHistoryStackEntry(),
                      pm, pgehl, pnb, logPnb, wp);

     int thres = pUpdateThreshold[getIndUpd(branch_pc)];

     return thres;
 }

 void
 MPP_StatisticalCorrector_64KB::gUpdates(ThreadID tid, Addr pc, bool taken,
         StatisticalCorrector::BranchInfo* bi, int64_t phist)
 {
     MPP_SCThreadHistory *sh = static_cast<MPP_SCThreadHistory *>(scHistory);

     gUpdate((pc << 1) + bi->predBeforeSC, taken, sh->globalHist << 11,
             gm, ggehl, gnb, logGnb, wg, bi);

     gUpdate(pc, taken, sh->getLocalHistory(1, pc),
             lm, lgehl, lnb, logLnb, wl, bi);

     gUpdate(pc, taken, sh->getLocalHistory(2, pc),
             sm, sgehl, snb, logSnb, ws, bi);

     gUpdate(pc, taken, sh->getLocalHistory(3, pc) << 11,
             tm, tgehl, tnb, logTnb, wt, bi);

     gUpdate(pc, taken, sh->getHistoryStackEntry(),
             pm, pgehl, pnb, logPnb, wp, bi);
 }

 void
 MPP_StatisticalCorrector_64KB::scHistoryUpdate(Addr branch_pc,
         const StaticInstPtr &inst, bool taken,
         StatisticalCorrector::BranchInfo *bi, Addr corrTarget)
 {
     int brtype = inst->isDirectCtrl() ? 0 : 2;
     if (! inst->isUncondCtrl()) {
         ++brtype;
     }

     MPP_SCThreadHistory *sh = static_cast<MPP_SCThreadHistory *>(scHistory);

     if (brtype & 1) {
         sh->globalHist = (sh->globalHist << 1) + taken;
         sh->updateLocalHistory(2, branch_pc, taken,
                               (branch_pc ^ (branch_pc >> 4)) & 15);
         sh->updateLocalHistory(3, branch_pc, taken);
     }
     sh->updateHistoryStack(corrTarget, taken, inst->isCall(),
                            inst->isReturn());

     StatisticalCorrector::scHistoryUpdate(branch_pc, inst, taken, bi,
                                           corrTarget);
 }

 size_t
 MPP_StatisticalCorrector_64KB::getSizeInBits() const
 {
     size_t bits = 16; //global histories

     bits += (1 << logSizeUp) * pUpdateThresholdWidth;

     bits += scCountersWidth * 2 * (1 << logBias); //2 bias arrays

     bits += (gnb - 2) * (1 << logGnb) * (scCountersWidth - 1) +
             (1 << (logGnb - 1)) * (2 * scCountersWidth - 1);

     bits += (pnb - 2) * (1 << logPnb) * (scCountersWidth - 1) +
             (1 << (logPnb - 1)) * (2 * scCountersWidth - 1);

     bits += (lnb - 2) * (1 << logLnb) * (scCountersWidth - 1) +
             (1 << (logLnb - 1)) * (2 * scCountersWidth - 1);

     bits += numEntriesFirstLocalHistories * lm[0];

     bits += (snb - 2) * (1 << logSnb) * (scCountersWidth - 1) +
             (1 << (logSnb - 1)) * (2 * scCountersWidth - 1);

     bits += numEntriesSecondLocalHistories * sm[0];

     bits += (tnb - 2) * (1 << logTnb) * (scCountersWidth - 1) +
             (1 << (logTnb - 1)) * (2 * scCountersWidth - 1);

     /* tm[0] is artificially increased by 11 to accomodate IMLI */
     bits += numEntriesThirdLocalHistories * (tm[0] - 11);

     bits += 16 * 16; // History stack
     bits += 4;       // History stack pointer

     bits += 3 * chooserConfWidth; // 3 chooser counters

     return bits;
 }

 MultiperspectivePerceptronTAGE64KB::MultiperspectivePerceptronTAGE64KB(
         const MultiperspectivePerceptronTAGE64KBParams &p)
     : MultiperspectivePerceptronTAGE(p)
 {
 }

 void
 MultiperspectivePerceptronTAGE64KB::createSpecs()
 {
     addSpec(new BLURRYPATH(5, 15, -1, 2.25, 0, 6, *this));
     addSpec(new BLURRYPATH(8, 10, -1, 2.25, 0, 6, *this));
     addSpec(new RECENCYPOS(31, 3.5, 0, 6, *this));
     addSpec(new GHISTMODPATH(3, 7, 1, 2.24, 0, 6, *this));
     addSpec(new MODPATH(3, 20, 3, 2.24, 0, 6, *this));
     addSpec(new IMLI(1, 2.23, 0, 6, *this));
     addSpec(new IMLI(4, 1.98, 0, 6, *this));
     addSpec(new RECENCY(9, 3, -1, 2.51, 0, 6, *this));
     addSpec(new ACYCLIC(12, -1, -1, 2.0, 0, 6, *this));
 }

 } // namespace branch_prediction
 } // namespace gem5
	/*
	* Copyright 2019 Texas A&M University
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions are met:
	*
	* 1. Redistributions of source code must retain the above copyright notice,
	* this list of conditions and the following disclaimer.
	*
	* 2. Redistributions in binary form must reproduce the above copyright notice,
	* this list of conditions and the following disclaimer in the documentation
	* and/or other materials provided with the distribution.
	*
	* 3. Neither the name of the copyright holder nor the names of its
	* contributors may be used to endorse or promote products derived from this
	* software without specific prior written permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	* Author: Daniel A. Jiménez
	* Adapted to gem5 by: Javier Bueno Hedo
	*
	*/

	/*
	* Multiperspective Perceptron Predictor with TAGE (by Daniel A. Jiménez)
	* 64 KB version
	*/

	#include "cpu/pred/multiperspective_perceptron_tage_64KB.hh"

	namespace gem5
	{

	namespace branch_prediction
	{

	MPP_StatisticalCorrector_64KB::MPP_StatisticalCorrector_64KB(
	const MPP_StatisticalCorrector_64KBParams &p)
	: MPP_StatisticalCorrector(p),
	numEntriesSecondLocalHistories(p.numEntriesSecondLocalHistories),
	numEntriesThirdLocalHistories(p.numEntriesThirdLocalHistories),
	snb(p.snb),
	logSnb(p.logSnb),
	sm(p.sm),
	tnb(p.tnb),
	logTnb(p.logTnb),
	tm(p.tm)
	{
	initGEHLTable(snb, sm, sgehl, logSnb, ws, -1);
	initGEHLTable(tnb, tm, tgehl, logTnb, wt, -1);
	}

	MPP_StatisticalCorrector_64KB::SCThreadHistory*
	MPP_StatisticalCorrector_64KB::makeThreadHistory()
	{
	MPP_SCThreadHistory *sh = new MPP_SCThreadHistory();

	sh->setNumOrdinalHistories(3);
	sh->initLocalHistory(1, numEntriesFirstLocalHistories, 4);
	sh->initLocalHistory(2, numEntriesSecondLocalHistories, 5);
	sh->initLocalHistory(3, numEntriesThirdLocalHistories, 3);

	return sh;
	}


	void
	MPP_StatisticalCorrector_64KB::getBiasLSUM(Addr branch_pc,
	StatisticalCorrector::BranchInfo* bi, int &lsum) const
	{
	int8_t ctr = bias[getIndBias(branch_pc, bi, false /* unused */)];
	lsum += 2.09 * ctr;
	ctr = biasSK[getIndBiasSK(branch_pc, bi)];
	lsum += 2.08 * ctr;
	}

	int
	MPP_StatisticalCorrector_64KB::gPredictions(ThreadID tid, Addr branch_pc,
	StatisticalCorrector::BranchInfo* bi, int & lsum, int64_t phist)
	{
	MPP_SCThreadHistory sh = static_cast<MPP_SCThreadHistory >(scHistory);
	unsigned int pc = branch_pc;
	lsum += gPredict((pc << 1) + bi->predBeforeSC, sh->globalHist << 11,
	gm, ggehl, gnb, logGnb, wg);

	// Local History #1
	lsum += 2.02 * gPredict(branch_pc, sh->getLocalHistory(1, branch_pc),
	lm, lgehl, lnb, logLnb, wl);
	if (sh->getLocalHistory(1, branch_pc) == 2047) lsum += 4;
	if (sh->getLocalHistory(1, branch_pc) == 0) lsum -= 4;

	// Local History #3
	lsum += gPredict(branch_pc, sh->getLocalHistory(3, branch_pc) << 11,
	tm, tgehl, tnb, logTnb, wt);

	// Local History #2
	lsum += gPredict(branch_pc, sh->getLocalHistory(2, branch_pc),
	sm, sgehl, snb, logSnb, ws);

	lsum += gPredict(branch_pc, sh->getHistoryStackEntry(),
	pm, pgehl, pnb, logPnb, wp);

	int thres = pUpdateThreshold[getIndUpd(branch_pc)];

	return thres;
	}

	void
	MPP_StatisticalCorrector_64KB::gUpdates(ThreadID tid, Addr pc, bool taken,
	StatisticalCorrector::BranchInfo* bi, int64_t phist)
	{
	MPP_SCThreadHistory sh = static_cast<MPP_SCThreadHistory >(scHistory);

	gUpdate((pc << 1) + bi->predBeforeSC, taken, sh->globalHist << 11,
	gm, ggehl, gnb, logGnb, wg, bi);

	gUpdate(pc, taken, sh->getLocalHistory(1, pc),
	lm, lgehl, lnb, logLnb, wl, bi);

	gUpdate(pc, taken, sh->getLocalHistory(2, pc),
	sm, sgehl, snb, logSnb, ws, bi);

	gUpdate(pc, taken, sh->getLocalHistory(3, pc) << 11,
	tm, tgehl, tnb, logTnb, wt, bi);

	gUpdate(pc, taken, sh->getHistoryStackEntry(),
	pm, pgehl, pnb, logPnb, wp, bi);
	}

	void
	MPP_StatisticalCorrector_64KB::scHistoryUpdate(Addr branch_pc,
	const StaticInstPtr &inst, bool taken,
	StatisticalCorrector::BranchInfo *bi, Addr corrTarget)
	{
	int brtype = inst->isDirectCtrl() ? 0 : 2;
	if (! inst->isUncondCtrl()) {
	++brtype;
	}

	MPP_SCThreadHistory sh = static_cast<MPP_SCThreadHistory >(scHistory);

	if (brtype & 1) {
	sh->globalHist = (sh->globalHist << 1) + taken;
	sh->updateLocalHistory(2, branch_pc, taken,
	(branch_pc ^ (branch_pc >> 4)) & 15);
	sh->updateLocalHistory(3, branch_pc, taken);
	}
	sh->updateHistoryStack(corrTarget, taken, inst->isCall(),
	inst->isReturn());

	StatisticalCorrector::scHistoryUpdate(branch_pc, inst, taken, bi,
	corrTarget);
	}

	size_t
	MPP_StatisticalCorrector_64KB::getSizeInBits() const
	{
	size_t bits = 16; //global histories

	bits += (1 << logSizeUp) * pUpdateThresholdWidth;

	bits += scCountersWidth * 2 * (1 << logBias); //2 bias arrays

	bits += (gnb - 2) * (1 << logGnb) * (scCountersWidth - 1) +
	(1 << (logGnb - 1)) * (2 * scCountersWidth - 1);

	bits += (pnb - 2) * (1 << logPnb) * (scCountersWidth - 1) +
	(1 << (logPnb - 1)) * (2 * scCountersWidth - 1);

	bits += (lnb - 2) * (1 << logLnb) * (scCountersWidth - 1) +
	(1 << (logLnb - 1)) * (2 * scCountersWidth - 1);

	bits += numEntriesFirstLocalHistories * lm[0];

	bits += (snb - 2) * (1 << logSnb) * (scCountersWidth - 1) +
	(1 << (logSnb - 1)) * (2 * scCountersWidth - 1);

	bits += numEntriesSecondLocalHistories * sm[0];

	bits += (tnb - 2) * (1 << logTnb) * (scCountersWidth - 1) +
	(1 << (logTnb - 1)) * (2 * scCountersWidth - 1);

	/* tm[0] is artificially increased by 11 to accomodate IMLI */
	bits += numEntriesThirdLocalHistories * (tm[0] - 11);

	bits += 16 * 16; // History stack
	bits += 4; // History stack pointer

	bits += 3 * chooserConfWidth; // 3 chooser counters

	return bits;
	}

	MultiperspectivePerceptronTAGE64KB::MultiperspectivePerceptronTAGE64KB(
	const MultiperspectivePerceptronTAGE64KBParams &p)
	: MultiperspectivePerceptronTAGE(p)
	{
	}

	void
	MultiperspectivePerceptronTAGE64KB::createSpecs()
	{
	addSpec(new BLURRYPATH(5, 15, -1, 2.25, 0, 6, *this));
	addSpec(new BLURRYPATH(8, 10, -1, 2.25, 0, 6, *this));
	addSpec(new RECENCYPOS(31, 3.5, 0, 6, *this));
	addSpec(new GHISTMODPATH(3, 7, 1, 2.24, 0, 6, *this));
	addSpec(new MODPATH(3, 20, 3, 2.24, 0, 6, *this));
	addSpec(new IMLI(1, 2.23, 0, 6, *this));
	addSpec(new IMLI(4, 1.98, 0, 6, *this));
	addSpec(new RECENCY(9, 3, -1, 2.51, 0, 6, *this));
	addSpec(new ACYCLIC(12, -1, -1, 2.0, 0, 6, *this));
	}

	} // namespace branch_prediction
	} // namespace gem5