#include <multiperspective_perceptron.hh>

Inheritance diagram for gem5::branch_prediction::MultiperspectivePerceptron:

Classes
class	ACYCLIC

class	BIAS

class	BLURRYPATH

struct	FilterEntry
	Entry of the branch filter. More...

class	GHIST
	Available features. More...

class	GHISTMODPATH

class	GHISTPATH

struct	HistorySpec
	Base class to implement the predictor tables. More...

class	IMLI

class	LOCAL

class	LocalHistories
	Local history entries, each enty contains the history of directions taken by a given branch. More...

class	MODHIST

class	MODPATH

class	MPPBranchInfo
	Branch information data. More...

class	PATH

class	RECENCY

class	RECENCYPOS

class	SGHISTPATH

struct	ThreadData
	History data is kept for each thread. More...

Public Member Functions
	MultiperspectivePerceptron (const MultiperspectivePerceptronParams &params)

void	setExtraBits (int bits)
	Sets the starting number of storage bits to compute the number of table entries.

void	init () override
	init() is called after all C++ SimObjects have been created and all ports are connected.

bool	lookup (ThreadID tid, Addr branch_addr, void *&bp_history) override
	Looks up a given conditional branch PC of in the BP to see if it is taken or not taken.

void	updateHistories (ThreadID tid, Addr pc, bool uncond, bool taken, Addr target, void *&bp_history) override
	Ones done with the prediction this function updates the path and global history.

void	update (ThreadID tid, Addr pc, bool taken, void *&bp_history, bool squashed, const StaticInstPtr &inst, Addr target) override
	Updates the BP with taken/not taken information.

void	squash (ThreadID tid, void *&bp_history) override

Public Member Functions inherited from gem5::branch_prediction::BPredUnit
	BPredUnit (const Params &p)
	Branch Predictor Unit (BPU) interface functions.

void	regProbePoints () override
	Register probe points for this object.

void	drainSanityCheck () const
	Perform sanity checks after a drain.

bool	predict (const StaticInstPtr &inst, const InstSeqNum &seqNum, PCStateBase &pc, ThreadID tid)
	Predicts whether or not the instruction is a taken branch, and the target of the branch if it is taken.

void	update (const InstSeqNum &done_sn, ThreadID tid)
	Tells the branch predictor to commit any updates until the given sequence number.

void	squash (const InstSeqNum &squashed_sn, ThreadID tid)
	Squashes all outstanding updates until a given sequence number.

void	squash (const InstSeqNum &squashed_sn, const PCStateBase &corr_target, bool actually_taken, ThreadID tid, bool from_commit=true)
	Squashes all outstanding updates until a given sequence number, and corrects that sn's update with the proper address and taken/not taken.

Public Member Functions inherited from gem5::SimObject
const Params &	params () const

	SimObject (const Params &p)

virtual	~SimObject ()

virtual void	loadState (CheckpointIn &cp)
	loadState() is called on each SimObject when restoring from a checkpoint.

virtual void	initState ()
	initState() is called on each SimObject when not restoring from a checkpoint.

virtual void	regProbeListeners ()
	Register probe listeners for this object.

ProbeManager *	getProbeManager ()
	Get the probe manager for this object.

virtual Port &	getPort (const std::string &if_name, PortID idx=InvalidPortID)
	Get a port with a given name and index.

virtual void	startup ()
	startup() is the final initialization call before simulation.

DrainState	drain () override
	Provide a default implementation of the drain interface for objects that don't need draining.

virtual void	memWriteback ()
	Write back dirty buffers to memory using functional writes.

virtual void	memInvalidate ()
	Invalidate the contents of memory buffers.

void	serialize (CheckpointOut &cp) const override
	Serialize an object.

void	unserialize (CheckpointIn &cp) override
	Unserialize an object.

Public Member Functions inherited from gem5::EventManager
EventQueue *	eventQueue () 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.

void	setCurTick (Tick newVal)

	EventManager (EventManager &em)
	Event manger manages events in the event queue.

	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.

void	serializeSection (CheckpointOut &cp, const std::string &name) const

void	unserializeSection (CheckpointIn &cp, const char *name)
	Unserialize an a child object.

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.

virtual void	notifyFork ()
	Notify a child process of a fork.

Public Member Functions inherited from gem5::statistics::Group
	Group (Group parent, const char name=nullptr)
	Construct a new statistics group.

virtual	~Group ()

virtual void	regStats ()
	Callback to set stat parameters.

virtual void	resetStats ()
	Callback to reset stats.

virtual void	preDumpStats ()
	Callback before stats are dumped.

void	addStat (statistics::Info *info)
	Register a stat with this group.

const std::map< std::string, Group * > &	getStatGroups () const
	Get all child groups associated with this object.

const std::vector< Info * > &	getStats () const
	Get all stats associated with this object.

void	addStatGroup (const char name, Group block)
	Add a stat block as a child of this block.

const Info *	resolveStat (std::string name) const
	Resolve a stat by its name within this group.

void	mergeStatGroup (Group *block)
	Merge the contents (stats & children) of a block to this block.

	Group ()=delete

	Group (const Group &)=delete

Group &	operator= (const Group &)=delete

Public Member Functions inherited from gem5::Named
	Named (const std::string &name_)

virtual	~Named ()=default

virtual std::string	name () const

Protected Member Functions
void	insertModhistSpec (int p1, int p2)
	Auxiliary function for MODHIST and GHISTMODPATH features.

void	insertModpathSpec (int p1, int p2)
	Auxiliary function for MODPATH and GHISTMODPATH features.

int	insert (std::vector< int > &v, int x)
	Auxiliary function used by insertModhistSpec and insertModpathSpec.

void	computeBits (int num_filter_entries, int nlocal_histories, int local_history_length, bool ignore_path_size)
	Computes the size in bits of the structures needed to keep track of the history and the predictor tables and assigns the sizes of those tables that did not had their size specified.

virtual void	createSpecs ()=0
	Creates the tables of the predictor.

unsigned int	getIndex (ThreadID tid, const MPPBranchInfo &bi, const HistorySpec &spec, int index) const
	Get the position index of a predictor table.

void	findBest (ThreadID tid, std::vector< int > &best_preds) const
	Finds the best subset of features to use in case of a low-confidence branch, returns the result as an ordered vector of the indices to the predictor tables.

int	computeOutput (ThreadID tid, MPPBranchInfo &bi)
	Computes the output of the predictor for a given branch and the resulting best value in case the prediction has low confidence.

void	train (ThreadID tid, MPPBranchInfo &bi, bool taken)
	Trains the branch predictor with the given branch and direction.

void	satIncDec (bool taken, bool &sign, int &c, int max_weight) const
	Auxiliary function to increase a table counter depending on the direction of the branch.

void	addSpec (HistorySpec *spec)
	Add a table spec to the prefetcher.

Protected Member Functions inherited from gem5::branch_prediction::BPredUnit
bool	BTBValid (ThreadID tid, Addr instPC)
	Looks up a given PC in the BTB to see if a matching entry exists.

const PCStateBase *	BTBLookup (ThreadID tid, PCStateBase &instPC)
	Looks up a given PC in the BTB to get the predicted target.

const StaticInstPtr	BTBGetInst (ThreadID tid, Addr instPC)
	Looks up a given PC in the BTB to get current static instruction information.

void	BTBUpdate (ThreadID tid, Addr instPC, const PCStateBase &target)
	Updates the BTB with the target of a branch.

void	dump ()

probing::PMUUPtr	pmuProbePoint (const char *name)
	Helper method to instantiate probe points belonging to this object.

Protected Member Functions inherited from gem5::Drainable
	Drainable ()

virtual	~Drainable ()

virtual void	drainResume ()
	Resume execution after a successful drain.

void	signalDrainDone () const
	Signal that an object is drained.

Protected Attributes
const int	blockSize
	Predictor parameters.

const int	pcshift

const int	threshold

const int	bias0

const int	bias1

const int	biasmostly0

const int	biasmostly1

const int	nbest

const int	tunebits

const int	hshift

const unsigned long long int	imli_mask1

const unsigned long long int	imli_mask4

const unsigned long long int	recencypos_mask

const double	fudge

const int	n_sign_bits

const int	pcbit

const int	decay

const unsigned int	record_mask

const bool	hash_taken

const bool	tuneonly

const int	extra_rounds

const int	speed

const int	budgetbits

const bool	speculative_update

std::vector< ThreadData * >	threadData

std::vector< HistorySpec * >	specs
	Predictor tables.

std::vector< int >	table_sizes

bool	doing_local
	runtime values and data used to count the size in bits

bool	doing_recency

int	assoc

int	ghist_length

int	modghist_length

int	path_length

int	thresholdCounter

int	theta

int	extrabits

std::vector< int >	imli_counter_bits

std::vector< int >	modhist_indices

std::vector< int >	modhist_lengths

std::vector< int >	modpath_indices

std::vector< int >	modpath_lengths

std::vector< std::vector< int > >	blurrypath_bits

std::vector< std::vector< std::vector< bool > > >	acyclic_bits

Protected Attributes inherited from gem5::branch_prediction::BPredUnit
const unsigned	numThreads
	Number of the threads for which the branch history is maintained.

const bool	requiresBTBHit
	Requires the BTB to hit for returns and indirect branches.

const unsigned	instShiftAmt
	Number of bits to shift instructions by for predictor addresses.

std::vector< History >	predHist
	The per-thread predictor history.

BranchTargetBuffer *	btb
	The BTB.

ReturnAddrStack *	ras
	The return address stack.

IndirectPredictor *	iPred
	The indirect target predictor.

gem5::branch_prediction::BPredUnit::BPredUnitStats	stats

probing::PMUUPtr	ppBranches
	Branches seen by the branch predictor.

probing::PMUUPtr	ppMisses
	Miss-predicted branches.

Protected Attributes inherited from gem5::SimObject
const SimObjectParams &	_params
	Cached copy of the object parameters.

Protected Attributes inherited from gem5::EventManager
EventQueue *	eventq
	A pointer to this object's event queue.

Static Protected Attributes
static int	xlat []
	Transfer function for 6-width tables.

static int	xlat4 []
	Transfer function for 5-width tables.

Additional Inherited Members
Public Types inherited from gem5::SimObject
typedef SimObjectParams	Params

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.

static SimObject *	find (const char *name)
	Find the SimObject with the given name and return a pointer to it.

static void	setSimObjectResolver (SimObjectResolver *resolver)
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

static SimObjectResolver *	getSimObjectResolver ()
	There is a single object name resolver, and it is only set when simulation is restoring from checkpoints.

Static Public Member Functions inherited from gem5::Serializable
static const std::string &	currentSection ()
	Gets the fully-qualified name of the active section.

static void	generateCheckpointOut (const std::string &cpt_dir, std::ofstream &outstream)
	Generate a checkpoint file so that the serialization can be routed to it.

Detailed Description

Definition at line 66 of file multiperspective_perceptron.hh.

Constructor & Destructor Documentation

◆ MultiperspectivePerceptron()

gem5::branch_prediction::MultiperspectivePerceptron::MultiperspectivePerceptron ( const MultiperspectivePerceptronParams & params )

Definition at line 131 of file multiperspective_perceptron.cc.

References fatal_if, and speculative_update.

Member Function Documentation

◆ addSpec()

void gem5::branch_prediction::MultiperspectivePerceptron::addSpec ( HistorySpec * spec )

inlineprotected

Add a table spec to the prefetcher.

Definition at line 499 of file multiperspective_perceptron.hh.

References specs.

Referenced by gem5::branch_prediction::MultiperspectivePerceptron64KB::createSpecs(), gem5::branch_prediction::MultiperspectivePerceptron8KB::createSpecs(), gem5::branch_prediction::MultiperspectivePerceptronTAGE64KB::createSpecs(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE8KB::createSpecs().

◆ computeBits()

void gem5::branch_prediction::MultiperspectivePerceptron::computeBits	(	int	num_filter_entries,
		int	nlocal_histories,
		int	local_history_length,
		bool	ignore_path_size )

protected

Computes the size in bits of the structures needed to keep track of the history and the predictor tables and assigns the sizes of those tables that did not had their size specified.

Parameters

num_filter_entries	number of entries of the filter
nlocal_histories	number of local history entries
local_history_length	size of each local history entry
ignore_path_size	ignore the path length storage

Definition at line 190 of file multiperspective_perceptron.cc.

References acyclic_bits, assoc, blurrypath_bits, budgetbits, doing_local, doing_recency, DPRINTF, extrabits, ghist_length, gem5::ArmISA::i, imli_counter_bits, gem5::ArmISA::len, modhist_lengths, modpath_lengths, n_sign_bits, path_length, specs, table_sizes, threshold, and tunebits.

Referenced by init().

◆ computeOutput()

int gem5::branch_prediction::MultiperspectivePerceptron::computeOutput	(	ThreadID	tid,
		MPPBranchInfo &	bi )

protected

Computes the output of the predictor for a given branch and the resulting best value in case the prediction has low confidence.

Parameters

tid	Thread ID of the branch
bi	branch informaiton data

Returns: resulting sum for low-confidence branch

Definition at line 322 of file multiperspective_perceptron.cc.

References gem5::PowerISA::bi, bias0, bias1, biasmostly0, biasmostly1, gem5::branch_prediction::MultiperspectivePerceptron::HistorySpec::coeff, findBest(), fudge, getIndex(), gem5::ArmISA::i, n_sign_bits, nbest, specs, threadData, threshold, gem5::X86ISA::val, gem5::branch_prediction::MultiperspectivePerceptron::HistorySpec::width, xlat, and xlat4.

Referenced by lookup().

◆ createSpecs()

virtual void gem5::branch_prediction::MultiperspectivePerceptron::createSpecs ( )

protectedpure virtual

Creates the tables of the predictor.

Implemented in gem5::branch_prediction::MultiperspectivePerceptron64KB, gem5::branch_prediction::MultiperspectivePerceptron8KB, gem5::branch_prediction::MultiperspectivePerceptronTAGE64KB, and gem5::branch_prediction::MultiperspectivePerceptronTAGE8KB.

Referenced by init().

◆ findBest()

void gem5::branch_prediction::MultiperspectivePerceptron::findBest	(	ThreadID	tid,
		std::vector< int > &	best_preds ) const

protected

Finds the best subset of features to use in case of a low-confidence branch, returns the result as an ordered vector of the indices to the predictor tables.

Parameters

tid	Thread ID of the branch
vector	to write the ordered list of indices of the best tables

Definition at line 264 of file multiperspective_perceptron.cc.

References gem5::ArmISA::i, gem5::MipsISA::index, nbest, threadData, and threshold.

Referenced by computeOutput().

◆ getIndex()

unsigned int gem5::branch_prediction::MultiperspectivePerceptron::getIndex	(	ThreadID	tid,
		const MPPBranchInfo &	bi,
		const HistorySpec &	spec,
		int	index ) const

protected

Get the position index of a predictor table.

Parameters

tid	Thread ID of the branch
bi	branch informaiton data
spec	predictor table
index	integer index of the predictor table

Returns: index to access the predictor table

Definition at line 291 of file multiperspective_perceptron.cc.

References gem5::PowerISA::bi, doing_recency, gem5::MipsISA::g, gem5::branch_prediction::MultiperspectivePerceptron::HistorySpec::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCYPOS::hash(), hshift, imli_mask1, imli_mask4, gem5::MipsISA::index, recencypos_mask, table_sizes, and threadData.

Referenced by computeOutput(), and train().

◆ init()

void gem5::branch_prediction::MultiperspectivePerceptron::init ( )

overridevirtual

init() is called after all C++ SimObjects have been created and all ports are connected.

Initializations that are independent of unserialization but rely on a fully instantiated and connected SimObject graph should be done here.

Reimplemented from gem5::SimObject.

Reimplemented in gem5::branch_prediction::MultiperspectivePerceptronTAGE.

Definition at line 158 of file multiperspective_perceptron.cc.

References acyclic_bits, assoc, blockSize, blurrypath_bits, computeBits(), createSpecs(), ghist_length, gem5::ArmISA::i, modhist_indices, modhist_lengths, modpath_indices, modpath_lengths, n_sign_bits, gem5::MipsISA::p, gem5::SimObject::params(), path_length, specs, table_sizes, and threadData.

Referenced by gem5::branch_prediction::MultiperspectivePerceptronTAGE::init().

◆ insert()

int gem5::branch_prediction::MultiperspectivePerceptron::insert	(	std::vector< int > &	v,
		int	x )

inlineprotected

Auxiliary function used by insertModhistSpec and insertModpathSpec.

Definition at line 424 of file multiperspective_perceptron.hh.

References gem5::ArmISA::i, gem5::ArmISA::v, and gem5::RiscvISA::x.

Referenced by insertModhistSpec(), and insertModpathSpec().

◆ insertModhistSpec()

void gem5::branch_prediction::MultiperspectivePerceptron::insertModhistSpec	(	int	p1,
		int	p2 )

inlineprotected

Auxiliary function for MODHIST and GHISTMODPATH features.

Definition at line 396 of file multiperspective_perceptron.hh.

References insert(), modghist_length, modhist_indices, and modhist_lengths.

Referenced by gem5::branch_prediction::MultiperspectivePerceptron::GHISTMODPATH::setBitRequirements(), and gem5::branch_prediction::MultiperspectivePerceptron::MODHIST::setBitRequirements().

◆ insertModpathSpec()

void gem5::branch_prediction::MultiperspectivePerceptron::insertModpathSpec	(	int	p1,
		int	p2 )

inlineprotected

Auxiliary function for MODPATH and GHISTMODPATH features.

Definition at line 410 of file multiperspective_perceptron.hh.

References insert(), modpath_indices, modpath_lengths, and path_length.

Referenced by gem5::branch_prediction::MultiperspectivePerceptron::GHISTMODPATH::setBitRequirements(), and gem5::branch_prediction::MultiperspectivePerceptron::MODPATH::setBitRequirements().

◆ lookup()

bool gem5::branch_prediction::MultiperspectivePerceptron::lookup	(	ThreadID	tid,
		Addr	pc,
		void *&	bp_history )

overridevirtual

Looks up a given conditional branch PC of in the BP to see if it is taken or not taken.

Interface functions to the conditional branch predictor

Parameters

pc	The PC to look up.
bp_history	Pointer that will be set to an object that has the branch predictor state associated with the lookup.

Returns: Whether the branch is taken or not taken.

Implements gem5::branch_prediction::BPredUnit.

Reimplemented in gem5::branch_prediction::MultiperspectivePerceptronTAGE.

Definition at line 595 of file multiperspective_perceptron.cc.

References gem5::PowerISA::bi, computeOutput(), gem5::ArmISA::f, pcshift, threadData, and threshold.

◆ satIncDec()

void gem5::branch_prediction::MultiperspectivePerceptron::satIncDec	(	bool	taken,
		bool &	sign,
		int &	c,
		int	max_weight ) const

protected

Auxiliary function to increase a table counter depending on the direction of the branch.

Parameters

taken	whether the branch was taken
sign	current sign of the table
c	current value of the table
max_weight	maximum value of the counter

Definition at line 385 of file multiperspective_perceptron.cc.

Referenced by train().

◆ setExtraBits()

void gem5::branch_prediction::MultiperspectivePerceptron::setExtraBits ( int bits )

Sets the starting number of storage bits to compute the number of table entries.

Parameters

bits	number of bits used

Definition at line 152 of file multiperspective_perceptron.cc.

References gem5::bits(), and extrabits.

Referenced by gem5::branch_prediction::MultiperspectivePerceptronTAGE::init().

◆ squash()

void gem5::branch_prediction::MultiperspectivePerceptron::squash	(	ThreadID	tid,
		void *&	bp_history )

overridevirtual

Parameters

tid	The thread id.
bp_history	Pointer to the history object. The predictor will need to update any state and delete the object.

Implements gem5::branch_prediction::BPredUnit.

Reimplemented in gem5::branch_prediction::MultiperspectivePerceptronTAGE.

Definition at line 841 of file multiperspective_perceptron.cc.

References gem5::PowerISA::bi.

◆ train()

void gem5::branch_prediction::MultiperspectivePerceptron::train	(	ThreadID	tid,
		MPPBranchInfo &	bi,
		bool	taken )

protected

Trains the branch predictor with the given branch and direction.

Parameters

tid	Thread ID of the branch
bi	branch informaiton data
taken	whether the branch was taken

Definition at line 422 of file multiperspective_perceptron.cc.

References gem5::PowerISA::bi, gem5::branch_prediction::MultiperspectivePerceptron::HistorySpec::coeff, extra_rounds, getIndex(), gem5::ArmISA::i, n_sign_bits, gem5::RiscvISA::pred, gem5::Random::random(), gem5::random_mt, satIncDec(), specs, speed, theta, threadData, threshold, thresholdCounter, tunebits, tuneonly, gem5::branch_prediction::MultiperspectivePerceptron::HistorySpec::width, xlat, and xlat4.

Referenced by update().

◆ update()

void gem5::branch_prediction::MultiperspectivePerceptron::update	(	ThreadID	tid,
		Addr	pc,
		bool	taken,
		void *&	bp_history,
		bool	squashed,
		const StaticInstPtr &	inst,
		Addr	target )

overridevirtual

Updates the BP with taken/not taken information.

Parameters

tid	The thread id.
PC	The branch's PC that will be updated.
taken	Whether the branch was taken or not taken.
bp_history	Pointer to the branch predictor state that is associated with the branch lookup that is being updated.
squashed	Set to true when this function is called during a squash operation.
inst	Static instruction information
target	The resolved target of the branch (only needed for squashed branches)

Todo: Make this update flexible enough to handle a global predictor.

Implements gem5::branch_prediction::BPredUnit.

Reimplemented in gem5::branch_prediction::MultiperspectivePerceptronTAGE.

Definition at line 637 of file multiperspective_perceptron.cc.

References gem5::ArmISA::a, assoc, gem5::PowerISA::bi, blockSize, decay, doing_recency, gem5::ArmISA::f, gem5::branch_prediction::MultiperspectivePerceptron::MPPBranchInfo::getHashFilter(), ghist_length, hash_taken, gem5::ArmISA::i, modhist_indices, modhist_lengths, modpath_indices, modpath_lengths, path_length, pcbit, gem5::Random::random(), gem5::random_mt, record_mask, gem5::branch_prediction::MultiperspectivePerceptron::FilterEntry::seenTaken, gem5::branch_prediction::MultiperspectivePerceptron::FilterEntry::seenUntaken, threadData, train(), and gem5::ArmISA::z.

◆ updateHistories()

void gem5::branch_prediction::MultiperspectivePerceptron::updateHistories	(	ThreadID	tid,
		Addr	pc,
		bool	uncond,
		bool	taken,
		Addr	target,
		void *&	bp_history )

overridevirtual

Ones done with the prediction this function updates the path and global history.

All branches call this function including unconditional once.

Parameters

tid	The thread id.
PC	The branch's PC that will be updated.
uncond	Wheather or not this branch is an unconditional branch.
taken	Whether or not the branch was taken
target	The final target of branch. Some modern predictors use the target in their history.
bp_history	Pointer that will be set to an object that has the branch predictor state associated with the lookup.

Implements gem5::branch_prediction::BPredUnit.

Reimplemented in gem5::branch_prediction::MultiperspectivePerceptronTAGE.

Definition at line 564 of file multiperspective_perceptron.cc.

References gem5::PowerISA::bi, blockSize, ghist_length, gem5::ArmISA::i, path_length, gem5::MipsISA::pc, pcbit, pcshift, and threadData.

Member Data Documentation

◆ acyclic_bits

std::vector<std::vector<std::vector<bool> > > gem5::branch_prediction::MultiperspectivePerceptron::acyclic_bits

protected

Definition at line 393 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), gem5::branch_prediction::MultiperspectivePerceptron::ACYCLIC::setBitRequirements(), and gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData().

◆ assoc

int gem5::branch_prediction::MultiperspectivePerceptron::assoc

protected

Definition at line 380 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::insertRecency(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCY::setBitRequirements(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCYPOS::setBitRequirements(), update(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updateHistories().

◆ bias0

const int gem5::branch_prediction::MultiperspectivePerceptron::bias0

protected

Definition at line 282 of file multiperspective_perceptron.hh.

Referenced by computeOutput().

◆ bias1

const int gem5::branch_prediction::MultiperspectivePerceptron::bias1

protected

Definition at line 283 of file multiperspective_perceptron.hh.

Referenced by computeOutput().

◆ biasmostly0

const int gem5::branch_prediction::MultiperspectivePerceptron::biasmostly0

protected

Definition at line 284 of file multiperspective_perceptron.hh.

Referenced by computeOutput().

◆ biasmostly1

const int gem5::branch_prediction::MultiperspectivePerceptron::biasmostly1

protected

Definition at line 285 of file multiperspective_perceptron.hh.

Referenced by computeOutput().

◆ blockSize

const int gem5::branch_prediction::MultiperspectivePerceptron::blockSize

protected

Predictor parameters.

Definition at line 279 of file multiperspective_perceptron.hh.

Referenced by gem5::branch_prediction::MultiperspectivePerceptron::ACYCLIC::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::GHIST::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::GHISTPATH::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::MODHIST::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::PATH::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCY::getHash(), gem5::branch_prediction::MultiperspectivePerceptron::SGHISTPATH::getHash(), init(), update(), and updateHistories().

◆ blurrypath_bits

std::vector<std::vector<int> > gem5::branch_prediction::MultiperspectivePerceptron::blurrypath_bits

protected

Definition at line 392 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), gem5::branch_prediction::MultiperspectivePerceptron::BLURRYPATH::setBitRequirements(), and gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData().

◆ budgetbits

const int gem5::branch_prediction::MultiperspectivePerceptron::budgetbits

protected

Definition at line 301 of file multiperspective_perceptron.hh.

Referenced by computeBits().

◆ decay

const int gem5::branch_prediction::MultiperspectivePerceptron::decay

protected

Definition at line 295 of file multiperspective_perceptron.hh.

Referenced by update().

◆ doing_local

bool gem5::branch_prediction::MultiperspectivePerceptron::doing_local

protected

runtime values and data used to count the size in bits

Definition at line 378 of file multiperspective_perceptron.hh.

Referenced by computeBits(), and gem5::branch_prediction::MultiperspectivePerceptron::LOCAL::setBitRequirements().

◆ doing_recency

bool gem5::branch_prediction::MultiperspectivePerceptron::doing_recency

protected

Definition at line 379 of file multiperspective_perceptron.hh.

Referenced by computeBits(), getIndex(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCY::setBitRequirements(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCYPOS::setBitRequirements(), and update().

◆ extra_rounds

const int gem5::branch_prediction::MultiperspectivePerceptron::extra_rounds

protected

Definition at line 299 of file multiperspective_perceptron.hh.

Referenced by train().

◆ extrabits

int gem5::branch_prediction::MultiperspectivePerceptron::extrabits

protected

Definition at line 386 of file multiperspective_perceptron.hh.

Referenced by computeBits(), and setExtraBits().

◆ fudge

const double gem5::branch_prediction::MultiperspectivePerceptron::fudge

protected

Definition at line 292 of file multiperspective_perceptron.hh.

Referenced by computeOutput().

◆ ghist_length

int gem5::branch_prediction::MultiperspectivePerceptron::ghist_length

protected

Definition at line 381 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), gem5::branch_prediction::MultiperspectivePerceptron::GHIST::setBitRequirements(), gem5::branch_prediction::MultiperspectivePerceptron::GHISTPATH::setBitRequirements(), update(), and updateHistories().

◆ hash_taken

const bool gem5::branch_prediction::MultiperspectivePerceptron::hash_taken

protected

Definition at line 297 of file multiperspective_perceptron.hh.

Referenced by update().

◆ hshift

const int gem5::branch_prediction::MultiperspectivePerceptron::hshift

protected

Definition at line 288 of file multiperspective_perceptron.hh.

Referenced by getIndex().

◆ imli_counter_bits

std::vector<int> gem5::branch_prediction::MultiperspectivePerceptron::imli_counter_bits

protected

Definition at line 387 of file multiperspective_perceptron.hh.

Referenced by computeBits(), and gem5::branch_prediction::MultiperspectivePerceptron::IMLI::setBitRequirements().

◆ imli_mask1

const unsigned long long int gem5::branch_prediction::MultiperspectivePerceptron::imli_mask1

protected

Definition at line 289 of file multiperspective_perceptron.hh.

Referenced by getIndex(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::getIndex().

◆ imli_mask4

const unsigned long long int gem5::branch_prediction::MultiperspectivePerceptron::imli_mask4

protected

Definition at line 290 of file multiperspective_perceptron.hh.

Referenced by getIndex(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::getIndex().

◆ modghist_length

int gem5::branch_prediction::MultiperspectivePerceptron::modghist_length

protected

Definition at line 382 of file multiperspective_perceptron.hh.

Referenced by insertModhistSpec().

◆ modhist_indices

std::vector<int> gem5::branch_prediction::MultiperspectivePerceptron::modhist_indices

protected

Definition at line 388 of file multiperspective_perceptron.hh.

Referenced by init(), insertModhistSpec(), gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData(), update(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updateHistories().

◆ modhist_lengths

std::vector<int> gem5::branch_prediction::MultiperspectivePerceptron::modhist_lengths

protected

Definition at line 389 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), insertModhistSpec(), gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData(), update(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updateHistories().

◆ modpath_indices

std::vector<int> gem5::branch_prediction::MultiperspectivePerceptron::modpath_indices

protected

Definition at line 390 of file multiperspective_perceptron.hh.

Referenced by init(), insertModpathSpec(), gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData(), update(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updateHistories().

◆ modpath_lengths

std::vector<int> gem5::branch_prediction::MultiperspectivePerceptron::modpath_lengths

protected

Definition at line 391 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), insertModpathSpec(), gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData(), update(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updateHistories().

◆ n_sign_bits

const int gem5::branch_prediction::MultiperspectivePerceptron::n_sign_bits

protected

Definition at line 293 of file multiperspective_perceptron.hh.

Referenced by computeBits(), computeOutput(), init(), gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData(), and train().

◆ nbest

const int gem5::branch_prediction::MultiperspectivePerceptron::nbest

protected

Definition at line 286 of file multiperspective_perceptron.hh.

Referenced by computeOutput(), and findBest().

◆ path_length

int gem5::branch_prediction::MultiperspectivePerceptron::path_length

protected

Definition at line 383 of file multiperspective_perceptron.hh.

Referenced by computeBits(), init(), insertModpathSpec(), gem5::branch_prediction::MultiperspectivePerceptron::GHISTPATH::setBitRequirements(), gem5::branch_prediction::MultiperspectivePerceptron::PATH::setBitRequirements(), update(), and updateHistories().

◆ pcbit

const int gem5::branch_prediction::MultiperspectivePerceptron::pcbit

protected

Definition at line 294 of file multiperspective_perceptron.hh.

Referenced by update(), and updateHistories().

◆ pcshift

const int gem5::branch_prediction::MultiperspectivePerceptron::pcshift

protected

Definition at line 280 of file multiperspective_perceptron.hh.

Referenced by gem5::branch_prediction::MultiperspectivePerceptron::MPPBranchInfo::hashPC(), lookup(), gem5::branch_prediction::MultiperspectivePerceptronTAGE::lookup(), updateHistories(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updateHistories().

◆ recencypos_mask

const unsigned long long int gem5::branch_prediction::MultiperspectivePerceptron::recencypos_mask

protected

Definition at line 291 of file multiperspective_perceptron.hh.

Referenced by getIndex().

◆ record_mask

const unsigned int gem5::branch_prediction::MultiperspectivePerceptron::record_mask

protected

Definition at line 296 of file multiperspective_perceptron.hh.

Referenced by update().

◆ specs

std::vector<HistorySpec *> gem5::branch_prediction::MultiperspectivePerceptron::specs

protected

Predictor tables.

Definition at line 374 of file multiperspective_perceptron.hh.

Referenced by addSpec(), computeBits(), computeOutput(), gem5::branch_prediction::MultiperspectivePerceptronTAGE::computePartialSum(), init(), train(), and gem5::branch_prediction::MultiperspectivePerceptronTAGE::updatePartial().

◆ speculative_update

const bool gem5::branch_prediction::MultiperspectivePerceptron::speculative_update

protected

Definition at line 302 of file multiperspective_perceptron.hh.

Referenced by MultiperspectivePerceptron().

◆ speed

const int gem5::branch_prediction::MultiperspectivePerceptron::speed

protected

Definition at line 300 of file multiperspective_perceptron.hh.

Referenced by train().

◆ table_sizes

std::vector<int> gem5::branch_prediction::MultiperspectivePerceptron::table_sizes

protected

Definition at line 375 of file multiperspective_perceptron.hh.

Referenced by computeBits(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCYPOS::getHash(), getIndex(), gem5::branch_prediction::MultiperspectivePerceptronTAGE::getIndex(), gem5::branch_prediction::MultiperspectivePerceptron::RECENCYPOS::hash(), init(), and gem5::branch_prediction::MultiperspectivePerceptron::ThreadData::ThreadData().

◆ theta

int gem5::branch_prediction::MultiperspectivePerceptron::theta

protected

Definition at line 385 of file multiperspective_perceptron.hh.

Referenced by train().

◆ threadData

std::vector<ThreadData *> gem5::branch_prediction::MultiperspectivePerceptron::threadData

protected

Definition at line 371 of file multiperspective_perceptron.hh.

◆ threshold

const int gem5::branch_prediction::MultiperspectivePerceptron::threshold

protected

Definition at line 281 of file multiperspective_perceptron.hh.

Referenced by computeBits(), computeOutput(), findBest(), lookup(), and train().

◆ thresholdCounter

int gem5::branch_prediction::MultiperspectivePerceptron::thresholdCounter

protected

Definition at line 384 of file multiperspective_perceptron.hh.

Referenced by train().

◆ tunebits

const int gem5::branch_prediction::MultiperspectivePerceptron::tunebits

protected

Definition at line 287 of file multiperspective_perceptron.hh.

Referenced by computeBits(), and train().

◆ tuneonly

const bool gem5::branch_prediction::MultiperspectivePerceptron::tuneonly

protected

Definition at line 298 of file multiperspective_perceptron.hh.

Referenced by train().

◆ xlat

int gem5::branch_prediction::MultiperspectivePerceptron::xlat

staticprotected

Initial value:

=
    {1,3,4,5,7,8,9,11,12,14,15,17,19,21,23,25,27,29,32,34,37,41,45,49,53,58,63,
     69,76,85,94,106,}

Transfer function for 6-width tables.

Definition at line 305 of file multiperspective_perceptron.hh.

Referenced by computeOutput(), and train().

◆ xlat4

int gem5::branch_prediction::MultiperspectivePerceptron::xlat4

staticprotected

Initial value:

=

{0,4,5,7,9,11,12,14,16,17,19,22,28,33,39,45,}

Transfer function for 5-width tables.

Definition at line 307 of file multiperspective_perceptron.hh.

Referenced by computeOutput(), and train().

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

cpu/pred/multiperspective_perceptron.hh
cpu/pred/multiperspective_perceptron.cc

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Static Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ MultiperspectivePerceptron()

Member Function Documentation

◆ addSpec()

◆ computeBits()

◆ computeOutput()

◆ createSpecs()

◆ findBest()

◆ getIndex()

◆ init()

◆ insert()

◆ insertModhistSpec()

◆ insertModpathSpec()

◆ lookup()

◆ satIncDec()

◆ setExtraBits()

◆ squash()

◆ train()

◆ update()

◆ updateHistories()

Member Data Documentation

◆ acyclic_bits

◆ assoc

◆ bias0

◆ bias1

◆ biasmostly0

◆ biasmostly1

◆ blockSize

◆ blurrypath_bits

◆ budgetbits

◆ decay

◆ doing_local

◆ doing_recency

◆ extra_rounds

◆ extrabits

◆ fudge

◆ ghist_length

◆ hash_taken

◆ hshift

◆ imli_counter_bits

◆ imli_mask1

◆ imli_mask4

◆ modghist_length

◆ modhist_indices

◆ modhist_lengths

◆ modpath_indices

◆ modpath_lengths

◆ n_sign_bits

◆ nbest

◆ path_length

◆ pcbit

◆ pcshift

◆ recencypos_mask

◆ record_mask

◆ specs

◆ speculative_update

◆ speed

◆ table_sizes

◆ theta

◆ threadData

◆ threshold

◆ thresholdCounter

◆ tunebits

◆ tuneonly

◆ xlat

◆ xlat4