gem5  v21.1.0.2
Public Member Functions | List of all members
gem5::branch_prediction::TAGE_SC_L_TAGE_8KB Class Reference

#include <tage_sc_l_8KB.hh>

Inheritance diagram for gem5::branch_prediction::TAGE_SC_L_TAGE_8KB:
gem5::branch_prediction::TAGE_SC_L_TAGE gem5::branch_prediction::TAGEBase gem5::SimObject gem5::EventManager gem5::Serializable gem5::Drainable gem5::statistics::Group gem5::Named

Public Member Functions

 TAGE_SC_L_TAGE_8KB (const TAGE_SC_L_TAGE_8KBParams &p)
 
void initFoldedHistories (ThreadHistory &history) override
 Initialization of the folded histories. More...
 
int gindex_ext (int index, int bank) const override
 
uint16_t gtag (ThreadID tid, Addr pc, int bank) const override
 Computes the partial tag of a tagged table. More...
 
void handleAllocAndUReset (bool alloc, bool taken, TAGEBase::BranchInfo *bi, int nrand) override
 Handles Allocation and U bits reset on an update. More...
 
void handleTAGEUpdate (Addr branch_pc, bool taken, TAGEBase::BranchInfo *bi) override
 Handles the update of the TAGE entries. More...
 
void resetUctr (uint8_t &u) override
 Algorithm for resetting a single U counter. More...
 
- Public Member Functions inherited from gem5::branch_prediction::TAGE_SC_L_TAGE
virtual TAGEBase::BranchInfomakeBranchInfo () override
 
 TAGE_SC_L_TAGE (const TAGE_SC_L_TAGEParams &p)
 
void calculateParameters () override
 Calculates the history lengths and some other paramters in derived classes. More...
 
void buildTageTables () override
 Instantiates the TAGE table entries. More...
 
void calculateIndicesAndTags (ThreadID tid, Addr branch_pc, TAGEBase::BranchInfo *bi) override
 On a prediction, calculates the TAGE indices and tags for all the different history lengths. More...
 
unsigned getUseAltIdx (TAGEBase::BranchInfo *bi, Addr branch_pc) override
 Calculation of the index for useAltPredForNewlyAllocated On this base TAGE implementation it is always 0. More...
 
void updateHistories (ThreadID tid, Addr branch_pc, bool taken, TAGEBase::BranchInfo *b, bool speculative, const StaticInstPtr &inst, Addr target) override
 (Speculatively) updates global histories (path and direction). More...
 
int bindex (Addr pc_in) const override
 Computes the index used to access the bimodal table. More...
 
int gindex (ThreadID tid, Addr pc, int bank) const override
 Computes the index used to access a partially tagged table. More...
 
int F (int phist, int size, int bank) const override
 Utility function to shuffle the path history depending on which tagged table we are accessing. More...
 
void squash (ThreadID tid, bool taken, TAGEBase::BranchInfo *bi, Addr target) override
 Restores speculatively updated path and direction histories. More...
 
void updatePathAndGlobalHistory (ThreadHistory &tHist, int brtype, bool taken, Addr branch_pc, Addr target)
 
void adjustAlloc (bool &alloc, bool taken, bool pred_taken) override
 Extra calculation to tell whether TAGE allocaitons may happen or not on an update For this base TAGE implementation it does nothing. More...
 
void handleUReset () override
 Handles the U bits reset. More...
 
int calcDep (TAGEBase::BranchInfo *bi)
 
bool getBimodePred (Addr branch_pc, TAGEBase::BranchInfo *tage_bi) const override
 Get a branch prediction from the bimodal predictor. More...
 
void extraAltCalc (TAGEBase::BranchInfo *bi) override
 Extra steps for calculating altTaken For this base TAGE class it does nothing. More...
 
- Public Member Functions inherited from gem5::branch_prediction::TAGEBase
 TAGEBase (const TAGEBaseParams &p)
 
void init () override
 init() is called after all C++ SimObjects have been created and all ports are connected. More...
 
void baseUpdate (Addr pc, bool taken, BranchInfo *bi)
 Updates the bimodal predictor. More...
 
void updateGHist (uint8_t *&h, bool dir, uint8_t *tab, int &PT)
 (Speculatively) updates the global branch history. More...
 
void update (ThreadID tid, Addr branch_pc, bool taken, BranchInfo *bi)
 Update TAGE. More...
 
virtual void condBranchUpdate (ThreadID tid, Addr branch_pc, bool taken, BranchInfo *bi, int nrand, Addr corrTarget, bool pred, bool preAdjustAlloc=false)
 Update TAGE for conditional branches. More...
 
bool tagePredict (ThreadID tid, Addr branch_pc, bool cond_branch, BranchInfo *bi)
 TAGE prediction called from TAGE::predict. More...
 
virtual void updateStats (bool taken, BranchInfo *bi)
 Update the stats. More...
 
virtual bool isHighConfidence (BranchInfo *bi) const
 
void btbUpdate (ThreadID tid, Addr branch_addr, BranchInfo *&bi)
 
unsigned getGHR (ThreadID tid, BranchInfo *bi) const
 
int8_t getCtr (int hitBank, int hitBankIndex) const
 
unsigned getTageCtrBits () const
 
int getPathHist (ThreadID tid) const
 
bool isSpeculativeUpdateEnabled () const
 
size_t getSizeInBits () const
 
- Public Member Functions inherited from gem5::SimObject
const Paramsparams () const
 
 SimObject (const Params &p)
 
virtual ~SimObject ()
 
virtual void loadState (CheckpointIn &cp)
 loadState() is called on each SimObject when restoring from a checkpoint. More...
 
virtual void initState ()
 initState() is called on each SimObject when not restoring from a checkpoint. More...
 
virtual void regProbePoints ()
 Register probe points for this object. More...
 
virtual void regProbeListeners ()
 Register probe listeners for this object. More...
 
ProbeManagergetProbeManager ()
 Get the probe manager for this object. More...
 
virtual PortgetPort (const std::string &if_name, PortID idx=InvalidPortID)
 Get a port with a given name and index. More...
 
virtual void startup ()
 startup() is the final initialization call before simulation. More...
 
DrainState drain () override
 Provide a default implementation of the drain interface for objects that don't need draining. More...
 
virtual void memWriteback ()
 Write back dirty buffers to memory using functional writes. More...
 
virtual void memInvalidate ()
 Invalidate the contents of memory buffers. More...
 
void serialize (CheckpointOut &cp) const override
 Serialize an object. More...
 
void unserialize (CheckpointIn &cp) override
 Unserialize an object. More...
 
- Public Member Functions inherited from gem5::EventManager
EventQueueeventQueue () const
 
void schedule (Event &event, Tick when)
 
void deschedule (Event &event)
 
void reschedule (Event &event, Tick when, bool always=false)
 
void schedule (Event *event, Tick when)
 
void deschedule (Event *event)
 
void reschedule (Event *event, Tick when, bool always=false)
 
void wakeupEventQueue (Tick when=(Tick) -1)
 This function is not needed by the usual gem5 event loop but may be necessary in derived EventQueues which host gem5 on other schedulers. More...
 
void setCurTick (Tick newVal)
 
 EventManager (EventManager &em)
 Event manger manages events in the event queue. More...
 
 EventManager (EventManager *em)
 
 EventManager (EventQueue *eq)
 
- Public Member Functions inherited from gem5::Serializable
 Serializable ()
 
virtual ~Serializable ()
 
void serializeSection (CheckpointOut &cp, const char *name) const
 Serialize an object into a new section. More...
 
void serializeSection (CheckpointOut &cp, const std::string &name) const
 
void unserializeSection (CheckpointIn &cp, const char *name)
 Unserialize an a child object. More...
 
void unserializeSection (CheckpointIn &cp, const std::string &name)
 
- Public Member Functions inherited from gem5::Drainable
DrainState drainState () const
 Return the current drain state of an object. More...
 
virtual void notifyFork ()
 Notify a child process of a fork. More...
 
- Public Member Functions inherited from gem5::statistics::Group
 Group (Group *parent, const char *name=nullptr)
 Construct a new statistics group. More...
 
virtual ~Group ()
 
virtual void regStats ()
 Callback to set stat parameters. More...
 
virtual void resetStats ()
 Callback to reset stats. More...
 
virtual void preDumpStats ()
 Callback before stats are dumped. More...
 
void addStat (statistics::Info *info)
 Register a stat with this group. More...
 
const std::map< std::string, Group * > & getStatGroups () const
 Get all child groups associated with this object. More...
 
const std::vector< Info * > & getStats () const
 Get all stats associated with this object. More...
 
void addStatGroup (const char *name, Group *block)
 Add a stat block as a child of this block. More...
 
const InforesolveStat (std::string name) const
 Resolve a stat by its name within this group. More...
 
void mergeStatGroup (Group *block)
 Merge the contents (stats & children) of a block to this block. More...
 
 Group ()=delete
 
 Group (const Group &)=delete
 
Groupoperator= (const Group &)=delete
 
- Public Member Functions inherited from gem5::Named
 Named (const std::string &name_)
 
virtual ~Named ()=default
 
virtual std::string name () const
 

Additional Inherited Members

- Public Types inherited from gem5::branch_prediction::TAGEBase
enum  {
  BIMODAL_ONLY = 0, TAGE_LONGEST_MATCH, BIMODAL_ALT_MATCH, TAGE_ALT_MATCH,
  LAST_TAGE_PROVIDER_TYPE = TAGE_ALT_MATCH
}
 
- Public Types inherited from gem5::SimObject
typedef SimObjectParams Params
 
- Static Public Member Functions inherited from gem5::branch_prediction::TAGEBase
template<typename T >
static void ctrUpdate (T &ctr, bool taken, int nbits)
 Updates a direction counter based on the actual branch outcome. More...
 
static void unsignedCtrUpdate (uint8_t &ctr, bool up, unsigned nbits)
 Updates an unsigned counter based on up/down parameter. More...
 
- Static Public Member Functions inherited from gem5::SimObject
static void serializeAll (const std::string &cpt_dir)
 Create a checkpoint by serializing all SimObjects in the system. More...
 
static SimObjectfind (const char *name)
 Find the SimObject with the given name and return a pointer to it. More...
 
static void setSimObjectResolver (SimObjectResolver *resolver)
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
static SimObjectResolvergetSimObjectResolver ()
 There is a single object name resolver, and it is only set when simulation is restoring from checkpoints. More...
 
- Static Public Member Functions inherited from gem5::Serializable
static const std::string & currentSection ()
 Gets the fully-qualified name of the active section. More...
 
static void generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
 Generate a checkpoint file so that the serialization can be routed to it. More...
 
- Protected Member Functions inherited from gem5::Drainable
 Drainable ()
 
virtual ~Drainable ()
 
virtual void drainResume ()
 Resume execution after a successful drain. More...
 
void signalDrainDone () const
 Signal that an object is drained. More...
 
- Protected Attributes inherited from gem5::branch_prediction::TAGEBase
const unsigned logRatioBiModalHystEntries
 
const unsigned nHistoryTables
 
const unsigned tagTableCounterBits
 
const unsigned tagTableUBits
 
const unsigned histBufferSize
 
const unsigned minHist
 
const unsigned maxHist
 
const unsigned pathHistBits
 
std::vector< unsigned > tagTableTagWidths
 
std::vector< int > logTagTableSizes
 
std::vector< bool > btablePrediction
 
std::vector< bool > btableHysteresis
 
TageEntry ** gtable
 
std::vector< ThreadHistorythreadHistory
 
int * histLengths
 
int * tableIndices
 
int * tableTags
 
std::vector< int8_t > useAltPredForNewlyAllocated
 
int64_t tCounter
 
uint64_t logUResetPeriod
 
const int64_t initialTCounterValue
 
unsigned numUseAltOnNa
 
unsigned useAltOnNaBits
 
unsigned maxNumAlloc
 
std::vector< bool > noSkip
 
const bool speculativeHistUpdate
 
const unsigned instShiftAmt
 
bool initialized
 
gem5::branch_prediction::TAGEBase::TAGEBaseStats stats
 
- Protected Attributes inherited from gem5::SimObject
const SimObjectParams & _params
 Cached copy of the object parameters. More...
 
- Protected Attributes inherited from gem5::EventManager
EventQueueeventq
 A pointer to this object's event queue. More...
 

Detailed Description

Definition at line 56 of file tage_sc_l_8KB.hh.

Constructor & Destructor Documentation

◆ TAGE_SC_L_TAGE_8KB()

gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::TAGE_SC_L_TAGE_8KB ( const TAGE_SC_L_TAGE_8KBParams &  p)
inline

Definition at line 59 of file tage_sc_l_8KB.hh.

Member Function Documentation

◆ gindex_ext()

int gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::gindex_ext ( int  index,
int  bank 
) const
overridevirtual

◆ gtag()

uint16_t gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::gtag ( ThreadID  tid,
Addr  pc,
int  bank 
) const
overridevirtual

Computes the partial tag of a tagged table.

Parameters
tidthe thread ID used to select the global histories to use.
pcThe unshifted branch PC.
bankThe partially tagged table to access.

Implements gem5::branch_prediction::TAGE_SC_L_TAGE.

Definition at line 171 of file tage_sc_l_8KB.cc.

References gem5::branch_prediction::TAGE_SC_L_TAGE::F(), gem5::branch_prediction::TAGEBase::histLengths, gem5::branch_prediction::TAGEBase::instShiftAmt, gem5::branch_prediction::TAGEBase::pathHistBits, gem5::MipsISA::pc, gem5::branch_prediction::TAGEBase::tagTableTagWidths, and gem5::branch_prediction::TAGEBase::threadHistory.

◆ handleAllocAndUReset()

void gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::handleAllocAndUReset ( bool  alloc,
bool  taken,
TAGEBase::BranchInfo bi,
int  nrand 
)
overridevirtual

◆ handleTAGEUpdate()

void gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::handleTAGEUpdate ( Addr  branch_pc,
bool  taken,
TAGEBase::BranchInfo bi 
)
overridevirtual

◆ initFoldedHistories()

void gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::initFoldedHistories ( ThreadHistory history)
overridevirtual

◆ resetUctr()

void gem5::branch_prediction::TAGE_SC_L_TAGE_8KB::resetUctr ( uint8_t &  u)
overridevirtual

Algorithm for resetting a single U counter.

Reimplemented from gem5::branch_prediction::TAGEBase.

Definition at line 249 of file tage_sc_l_8KB.cc.

References gem5::ArmISA::u.


The documentation for this class was generated from the following files:

Generated on Tue Sep 21 2021 12:28:49 for gem5 by doxygen 1.8.17