| /* |
| * 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) |
| */ |
| |
| #ifndef __CPU_PRED_MULTIPERSPECTIVE_PERCEPTRON_TAGE_HH__ |
| #define __CPU_PRED_MULTIPERSPECTIVE_PERCEPTRON_TAGE_HH__ |
| |
| #include "cpu/pred/loop_predictor.hh" |
| #include "cpu/pred/multiperspective_perceptron.hh" |
| #include "cpu/pred/statistical_corrector.hh" |
| #include "cpu/pred/tage_base.hh" |
| #include "params/MPP_LoopPredictor.hh" |
| #include "params/MPP_StatisticalCorrector.hh" |
| #include "params/MPP_TAGE.hh" |
| #include "params/MultiperspectivePerceptronTAGE.hh" |
| |
| class MPP_TAGE : public TAGEBase { |
| std::vector<unsigned int> tunedHistoryLengths; |
| public: |
| struct BranchInfo : public TAGEBase::BranchInfo { |
| BranchInfo(TAGEBase &tage) : TAGEBase::BranchInfo(tage) |
| {} |
| virtual ~BranchInfo() |
| {} |
| }; |
| |
| MPP_TAGE(const MPP_TAGEParams *p) : TAGEBase(p), |
| tunedHistoryLengths(p->tunedHistoryLengths) |
| {} |
| |
| void calculateParameters() override; |
| void handleTAGEUpdate(Addr branch_pc, bool taken, TAGEBase::BranchInfo* bi) |
| override; |
| void handleAllocAndUReset(bool alloc, bool taken, TAGEBase::BranchInfo* bi, |
| int nrand) override; |
| void handleUReset() override; |
| void resetUctr(uint8_t &u) override; |
| int bindex(Addr pc_in) const override; |
| bool isHighConfidence(TAGEBase::BranchInfo *bi) const override; |
| |
| unsigned getUseAltIdx(TAGEBase::BranchInfo* bi, Addr branch_pc) override; |
| void adjustAlloc(bool & alloc, bool taken, bool pred_taken) override; |
| void updateHistories(ThreadID tid, Addr branch_pc, bool taken, |
| TAGEBase::BranchInfo* b, bool speculative, |
| const StaticInstPtr &inst, Addr target) override; |
| |
| void updatePathAndGlobalHistory(ThreadHistory& tHist, int brtype, |
| bool taken, Addr branch_pc, Addr target); |
| }; |
| |
| class MPP_LoopPredictor : public LoopPredictor { |
| public: |
| MPP_LoopPredictor(MPP_LoopPredictorParams *p) : LoopPredictor(p) |
| {} |
| |
| bool calcConf(int index) const override; |
| bool optionalAgeInc() const override; |
| }; |
| |
| class MPP_StatisticalCorrector : public StatisticalCorrector { |
| protected: |
| int8_t thirdH; |
| // global branch history variation GEHL |
| const unsigned pnb; |
| const unsigned logPnb; |
| std::vector<int> pm; |
| std::vector<int8_t> * pgehl; |
| std::vector<int8_t> wp; |
| |
| // global branch history GEHL |
| const unsigned gnb; |
| const unsigned logGnb; |
| std::vector<int> gm; |
| std::vector<int8_t> * ggehl; |
| std::vector<int8_t> wg; |
| |
| struct MPP_SCThreadHistory : public StatisticalCorrector::SCThreadHistory |
| { |
| MPP_SCThreadHistory() : globalHist(0), historyStack(16, 0), |
| historyStackPointer(0) {} |
| int64_t globalHist; // global history |
| std::vector<int64_t> historyStack; |
| unsigned int historyStackPointer; |
| |
| int64_t getHistoryStackEntry() const |
| { |
| return historyStack[historyStackPointer]; |
| } |
| |
| void updateHistoryStack(Addr target, bool taken, bool is_call, |
| bool is_return) |
| { |
| unsigned int truncated_target = target; |
| historyStack[historyStackPointer] = |
| (historyStack[historyStackPointer] << 1) ^ (truncated_target ^ |
| (truncated_target >> 5) ^ taken); |
| if (is_return) { |
| historyStackPointer = (historyStackPointer - 1) % |
| historyStack.size(); |
| } |
| if (is_call) { |
| int index = (historyStackPointer + 1) % historyStack.size(); |
| historyStack[index] = historyStack[historyStackPointer]; |
| historyStackPointer = index; |
| } |
| } |
| unsigned int getPointer() const { return historyStackPointer; } |
| }; |
| |
| public: |
| struct BranchInfo : public StatisticalCorrector::BranchInfo { |
| virtual ~BranchInfo() |
| {} |
| }; |
| MPP_StatisticalCorrector(const MPP_StatisticalCorrectorParams *p); |
| |
| void initBias() override; |
| unsigned getIndBias(Addr branch_pc, StatisticalCorrector::BranchInfo* bi, |
| bool bias) const override; |
| unsigned getIndBiasSK(Addr branch_pc, StatisticalCorrector::BranchInfo* bi) |
| const override; |
| unsigned getIndBiasBank(Addr branch_pc, |
| StatisticalCorrector::BranchInfo* bi, int hitBank, |
| int altBank) const override; |
| unsigned getIndUpd(Addr branch_pc) const override; |
| int gIndexLogsSubstr(int nbr, int i) override; |
| |
| bool scPredict(ThreadID tid, Addr branch_pc, bool cond_branch, |
| StatisticalCorrector::BranchInfo* bi, bool prev_pred_taken, |
| bool bias_bit, bool use_conf_ctr, int8_t conf_ctr, |
| unsigned conf_bits, int hitBank, int altBank, int64_t phist, |
| int init_lsum) override; |
| |
| void condBranchUpdate(ThreadID tid, Addr branch_pc, bool taken, |
| StatisticalCorrector::BranchInfo *bi, |
| Addr corrTarget, bool b, int hitBank, int altBank, |
| int64_t phist) override; |
| |
| virtual void getBiasLSUM(Addr branch_pc, |
| StatisticalCorrector::BranchInfo *bi, int &lsum) const = 0; |
| |
| 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; |
| }; |
| |
| class MultiperspectivePerceptronTAGE : public MultiperspectivePerceptron |
| { |
| TAGEBase *tage; |
| LoopPredictor *loopPredictor; |
| StatisticalCorrector *statisticalCorrector; |
| |
| /** |
| * Branch information data type |
| */ |
| struct MPPTAGEBranchInfo : public MPPBranchInfo |
| { |
| TAGEBase::BranchInfo *tageBranchInfo; |
| LoopPredictor::BranchInfo *lpBranchInfo; |
| StatisticalCorrector::BranchInfo *scBranchInfo; |
| bool predictedTaken; |
| MPPTAGEBranchInfo(Addr pc, int pcshift, bool cond, TAGEBase &tage, |
| LoopPredictor &loopPredictor, |
| StatisticalCorrector &statisticalCorrector) |
| : MPPBranchInfo(pc, pcshift, cond), |
| tageBranchInfo(tage.makeBranchInfo()), |
| lpBranchInfo(loopPredictor.makeBranchInfo()), |
| scBranchInfo(statisticalCorrector.makeBranchInfo()), |
| predictedTaken(false) |
| {} |
| virtual ~MPPTAGEBranchInfo() |
| { |
| delete tageBranchInfo; |
| delete lpBranchInfo; |
| delete scBranchInfo; |
| } |
| }; |
| |
| unsigned int getIndex(ThreadID tid, MPPTAGEBranchInfo &bi, |
| const HistorySpec &spec, int index) const; |
| int computePartialSum(ThreadID tid, MPPTAGEBranchInfo &bi) const; |
| void updatePartial(ThreadID tid, MPPTAGEBranchInfo &bi, bool taken); |
| void updateHistories(ThreadID tid, MPPTAGEBranchInfo &bi, bool taken); |
| |
| public: |
| MultiperspectivePerceptronTAGE( |
| const MultiperspectivePerceptronTAGEParams *p); |
| |
| void init() override; |
| |
| bool lookup(ThreadID tid, Addr instPC, void * &bp_history) override; |
| |
| void update(ThreadID tid, Addr instPC, bool taken, |
| void *bp_history, bool squashed, |
| const StaticInstPtr & inst, |
| Addr corrTarget = MaxAddr) override; |
| void uncondBranch(ThreadID tid, Addr pc, void * &bp_history) override; |
| void squash(ThreadID tid, void *bp_history) override; |
| |
| }; |
| #endif//__CPU_PRED_MULTIPERSPECTIVE_PERCEPTRON_TAGE_HH__ |
