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/*
* Copyright (c) 2018 Metempsy Technology Consulting
* All rights reserved.
*
* Copyright (c) 2006 INRIA (Institut National de Recherche en
* Informatique et en Automatique / French National Research Institute
* for Computer Science and Applied Mathematics)
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* 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;
* neither the name of the copyright holders 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
* OWNER 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: André Seznec, Pau Cabre, Javier Bueno
*
*/
/*
* TAGE-SC-L branch predictor base class (devised by Andre Seznec)
* It consits of a TAGE + a statistical corrector (SC) + a loop predictor (L)
*/
#ifndef __CPU_PRED_TAGE_SC_L
#define __CPU_PRED_TAGE_SC_L
#include "cpu/pred/ltage.hh"
#include "cpu/pred/statistical_corrector.hh"
#include "params/TAGE_SC_L.hh"
#include "params/TAGE_SC_L_LoopPredictor.hh"
#include "params/TAGE_SC_L_TAGE.hh"
class TAGE_SC_L_TAGE : public TAGEBase {
const unsigned firstLongTagTable;
const unsigned longTagsSize;
const unsigned shortTagsSize;
const unsigned logTagTableSize;
const unsigned shortTagsTageFactor;
const unsigned longTagsTageFactor;
const bool truncatePathHist;
public:
struct BranchInfo : public TAGEBase::BranchInfo {
bool lowConf;
bool highConf;
bool altConf;
bool medConf;
BranchInfo(TAGEBase &tage) : TAGEBase::BranchInfo(tage),
lowConf(false), highConf(false), altConf(false), medConf(false)
{}
virtual ~BranchInfo()
{}
};
virtual TAGEBase::BranchInfo *makeBranchInfo() override;
TAGE_SC_L_TAGE(const TAGE_SC_L_TAGEParams *p)
: TAGEBase(p),
firstLongTagTable(p->firstLongTagTable),
longTagsSize(p->longTagsSize),
shortTagsSize(p->shortTagsSize),
logTagTableSize(p->logTagTableSize),
shortTagsTageFactor(p->shortTagsTageFactor),
longTagsTageFactor(p->longTagsTageFactor),
truncatePathHist(p->truncatePathHist)
{}
void calculateParameters() override;
void buildTageTables() override;
void calculateIndicesAndTags(
ThreadID tid, Addr branch_pc, TAGEBase::BranchInfo* bi) override;
unsigned getUseAltIdx(TAGEBase::BranchInfo* bi, Addr branch_pc) override;
void updateHistories(
ThreadID tid, Addr branch_pc, bool taken, TAGEBase::BranchInfo* b,
bool speculative, const StaticInstPtr &inst,
Addr target) override;
int bindex(Addr pc_in) const override;
int gindex(ThreadID tid, Addr pc, int bank) const override;
virtual int gindex_ext(int index, int bank) const = 0;
int F(int phist, int size, int bank) const override;
virtual uint16_t gtag(ThreadID tid, Addr pc, int bank) const override = 0;
void squash(ThreadID tid, bool taken, TAGEBase::BranchInfo *bi,
Addr target) override;
void updatePathAndGlobalHistory(
ThreadHistory & tHist, int brtype, bool taken,
Addr branch_pc, Addr target);
void adjustAlloc(bool & alloc, bool taken, bool pred_taken) override;
virtual void handleAllocAndUReset(bool alloc, bool taken,
TAGEBase::BranchInfo* bi, int nrand) override = 0;
void handleUReset() override;
virtual void handleTAGEUpdate(
Addr branch_pc, bool taken, TAGEBase::BranchInfo* bi) override = 0;
int calcDep(TAGEBase::BranchInfo* bi);
bool getBimodePred(Addr branch_pc,
TAGEBase::BranchInfo* tage_bi) const override;
void extraAltCalc(TAGEBase::BranchInfo* bi) override;
};
class TAGE_SC_L_LoopPredictor : public LoopPredictor
{
public:
TAGE_SC_L_LoopPredictor(TAGE_SC_L_LoopPredictorParams *p)
: LoopPredictor(p)
{}
virtual bool calcConf(int index) const override;
virtual bool optionalAgeInc() const override;
};
class TAGE_SC_L: public LTAGE
{
StatisticalCorrector *statisticalCorrector;
public:
TAGE_SC_L(const TAGE_SC_LParams *params);
bool predict(
ThreadID tid, Addr branch_pc, bool cond_branch, void* &b) override;
void regStats() override;
void update(ThreadID tid, Addr branch_addr, bool taken, void *bp_history,
bool squashed, const StaticInstPtr & inst,
Addr corrTarget = MaxAddr) override;
protected:
struct TageSCLBranchInfo : public LTageBranchInfo
{
StatisticalCorrector::BranchInfo *scBranchInfo;
TageSCLBranchInfo(TAGEBase &tage, StatisticalCorrector &sc,
LoopPredictor &lp)
: LTageBranchInfo(tage, lp), scBranchInfo(sc.makeBranchInfo())
{}
virtual ~TageSCLBranchInfo()
{
delete scBranchInfo;
}
};
// more provider types
enum {
SC = LAST_LTAGE_PROVIDER_TYPE + 1
};
};
#endif // __CPU_PRED_TAGE_SC_L
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