A standard instruction queue class. More...

#include <inst_queue.hh>

Classes
class	FUCompletion
	FU completion event class. More...

struct	IQIOStats

struct	IQStats

struct	ListOrderEntry
	Entry for the list age ordering by op class. More...

struct	PqCompare
	Struct for comparing entries to be added to the priority queue. More...

Public Types
typedef std::list< DynInstPtr >::iterator	ListIt

Public Member Functions
	InstructionQueue (CPU cpu_ptr, IEW iew_ptr, const BaseO3CPUParams &params)
	Constructs an IQ.

	~InstructionQueue ()
	Destructs the IQ.

std::string	name () const
	Returns the name of the IQ.

void	resetState ()
	Resets all instruction queue state.

void	setActiveThreads (std::list< ThreadID > *at_ptr)
	Sets active threads list.

void	setIssueToExecuteQueue (TimeBuffer< IssueStruct > *i2eQueue)
	Sets the timer buffer between issue and execute.

void	setTimeBuffer (TimeBuffer< TimeStruct > *tb_ptr)
	Sets the global time buffer.

bool	isDrained () const
	Determine if we are drained.

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

void	takeOverFrom ()
	Takes over execution from another CPU's thread.

int	entryAmount (ThreadID num_threads)
	Number of entries needed for given amount of threads.

void	resetEntries ()
	Resets max entries for all threads.

unsigned	numFreeEntries ()
	Returns total number of free entries.

unsigned	numFreeEntries (ThreadID tid)
	Returns number of free entries for a thread.

bool	isFull ()
	Returns whether or not the IQ is full.

bool	isFull (ThreadID tid)
	Returns whether or not the IQ is full for a specific thread.

bool	hasReadyInsts ()
	Returns if there are any ready instructions in the IQ.

void	insert (const DynInstPtr &new_inst)
	Inserts a new instruction into the IQ.

void	insertNonSpec (const DynInstPtr &new_inst)
	Inserts a new, non-speculative instruction into the IQ.

void	insertBarrier (const DynInstPtr &barr_inst)
	Inserts a memory or write barrier into the IQ to make sure loads and stores are ordered properly.

DynInstPtr	getInstToExecute ()
	Returns the oldest scheduled instruction, and removes it from the list of instructions waiting to execute.

DynInstPtr	getDeferredMemInstToExecute ()
	Gets a memory instruction that was referred due to a delayed DTB translation if it is now ready to execute.

DynInstPtr	getBlockedMemInstToExecute ()
	Gets a memory instruction that was blocked on the cache.

void	recordProducer (const DynInstPtr &inst)
	Records the instruction as the producer of a register without adding it to the rest of the IQ.

void	processFUCompletion (const DynInstPtr &inst, int fu_idx)
	Process FU completion event.

void	scheduleReadyInsts ()
	Schedules ready instructions, adding the ready ones (oldest first) to the queue to execute.

void	scheduleNonSpec (const InstSeqNum &inst)
	Schedules a single specific non-speculative instruction.

void	commit (const InstSeqNum &inst, ThreadID tid=0)
	Commits all instructions up to and including the given sequence number, for a specific thread.

int	wakeDependents (const DynInstPtr &completed_inst)
	Wakes all dependents of a completed instruction.

void	addReadyMemInst (const DynInstPtr &ready_inst)
	Adds a ready memory instruction to the ready list.

void	rescheduleMemInst (const DynInstPtr &resched_inst)
	Reschedules a memory instruction.

void	replayMemInst (const DynInstPtr &replay_inst)
	Replays a memory instruction.

void	deferMemInst (const DynInstPtr &deferred_inst)
	Defers a memory instruction when its DTB translation incurs a hw page table walk.

void	blockMemInst (const DynInstPtr &blocked_inst)
	Defers a memory instruction when it is cache blocked.

void	retryMemInst (const DynInstPtr &retry_inst)
	Retries a memory instruction in the next cycle.

void	cacheUnblocked ()
	Notify instruction queue that a previous blockage has resolved.

void	violation (const DynInstPtr &store, const DynInstPtr &faulting_load)
	Indicates an ordering violation between a store and a load.

void	squash (ThreadID tid)
	Squashes instructions for a thread.

unsigned	getCount (ThreadID tid)
	Returns the number of used entries for a thread.

void	printInsts ()
	Debug function to print all instructions.

Public Attributes
gem5::o3::InstructionQueue::IQIOStats	iqIOStats

Private Types
typedef std::priority_queue< DynInstPtr, std::vector< DynInstPtr >, PqCompare >	ReadyInstQueue

typedef std::map< InstSeqNum, DynInstPtr >::iterator	NonSpecMapIt

typedef std::list< ListOrderEntry >::iterator	ListOrderIt

Private Member Functions
void	doSquash (ThreadID tid)
	Does the actual squashing.

void	addToOrderList (OpClass op_class)
	Add an op class to the age order list.

void	moveToYoungerInst (ListOrderIt age_order_it)
	Called when the oldest instruction has been removed from a ready queue; this places that ready queue into the proper spot in the age order list.

bool	addToDependents (const DynInstPtr &new_inst)
	Adds an instruction to the dependency graph, as a consumer.

void	addToProducers (const DynInstPtr &new_inst)
	Adds an instruction to the dependency graph, as a producer.

void	addIfReady (const DynInstPtr &inst)
	Moves an instruction to the ready queue if it is ready.

int	countInsts ()
	Debugging function to count how many entries are in the IQ.

void	dumpLists ()
	Debugging function to dump all the list sizes, as well as print out the list of nonspeculative instructions.

void	dumpInsts ()
	Debugging function to dump out all instructions that are in the IQ.

Private Attributes
CPU *	cpu
	Pointer to the CPU.

memory::MemInterface *	dcacheInterface
	Cache interface.

IEW *	iewStage
	Pointer to IEW stage.

MemDepUnit	memDepUnit [MaxThreads]
	The memory dependence unit, which tracks/predicts memory dependences between instructions.

TimeBuffer< IssueStruct > *	issueToExecuteQueue
	The queue to the execute stage.

TimeBuffer< TimeStruct > *	timeBuffer
	The backwards time buffer.

TimeBuffer< TimeStruct >::wire	fromCommit
	Wire to read information from timebuffer.

FUPool *	fuPool
	Function unit pool.

std::list< DynInstPtr >	instList [MaxThreads]
	List of all the instructions in the IQ (some of which may be issued).

std::list< DynInstPtr >	instsToExecute
	List of instructions that are ready to be executed.

std::list< DynInstPtr >	deferredMemInsts
	List of instructions waiting for their DTB translation to complete (hw page table walk in progress).

std::list< DynInstPtr >	blockedMemInsts
	List of instructions that have been cache blocked.

std::list< DynInstPtr >	retryMemInsts
	List of instructions that were cache blocked, but a retry has been seen since, so they can now be retried.

ReadyInstQueue	readyInsts [Num_OpClasses]
	List of ready instructions, per op class.

std::map< InstSeqNum, DynInstPtr >	nonSpecInsts
	List of non-speculative instructions that will be scheduled once the IQ gets a signal from commit.

std::list< ListOrderEntry >	listOrder
	List that contains the age order of the oldest instruction of each ready queue.

bool	queueOnList [Num_OpClasses]
	Tracks if each ready queue is on the age order list.

ListOrderIt	readyIt [Num_OpClasses]
	Iterators of each ready queue.

DependencyGraph< DynInstPtr >	dependGraph

SMTQueuePolicy	iqPolicy
	IQ sharing policy for SMT.

ThreadID	numThreads
	Number of Total Threads.

std::list< ThreadID > *	activeThreads
	Pointer to list of active threads.

unsigned	count [MaxThreads]
	Per Thread IQ count.

unsigned	maxEntries [MaxThreads]
	Max IQ Entries Per Thread.

unsigned	freeEntries
	Number of free IQ entries left.

unsigned	numEntries
	The number of entries in the instruction queue.

unsigned	totalWidth
	The total number of instructions that can be issued in one cycle.

unsigned	numPhysRegs
	The number of physical registers in the CPU.

int	wbOutstanding
	Number of instructions currently in flight to FUs.

Cycles	commitToIEWDelay
	Delay between commit stage and the IQ.

InstSeqNum	squashedSeqNum [MaxThreads]
	The sequence number of the squashed instruction.

std::vector< bool >	regScoreboard
	A cache of the recently woken registers.

gem5::o3::InstructionQueue::IQStats	iqStats

Detailed Description

A standard instruction queue class.

It holds ready instructions, in order, in seperate priority queues to facilitate the scheduling of instructions. The IQ uses a separate linked list to track dependencies. Similar to the rename map and the free list, it expects that floating point registers have their indices start after the integer registers (ie with 96 int and 96 fp registers, regs 0-95 are integer and 96-191 are fp). This remains true even for both logical and physical register indices. The IQ depends on the memory dependence unit to track when memory operations are ready in terms of ordering; register dependencies are tracked normally. Right now the IQ also handles the execution timing; this is mainly to allow back-to-back scheduling without requiring IEW to be able to peek into the IQ. At the end of the execution latency, the instruction is put into the queue to execute, where it will have the execute() function called on it.

Todo: : Make IQ able to handle multiple FU pools.

Definition at line 98 of file inst_queue.hh.

Member Typedef Documentation

◆ ListIt

typedef std::list<DynInstPtr>::iterator gem5::o3::InstructionQueue::ListIt

Definition at line 102 of file inst_queue.hh.

◆ ListOrderIt

typedef std::list<ListOrderEntry>::iterator gem5::o3::InstructionQueue::ListOrderIt

private

Definition at line 389 of file inst_queue.hh.

◆ NonSpecMapIt

typedef std::map<InstSeqNum,DynInstPtr>::iterator gem5::o3::InstructionQueue::NonSpecMapIt

private

Definition at line 371 of file inst_queue.hh.

◆ ReadyInstQueue

typedef std::priority_queue< DynInstPtr, std::vector<DynInstPtr>, PqCompare> gem5::o3::InstructionQueue::ReadyInstQueue

private

Definition at line 355 of file inst_queue.hh.

Constructor & Destructor Documentation

◆ InstructionQueue()

gem5::o3::InstructionQueue::InstructionQueue	(	CPU *	cpu_ptr,
		IEW *	iew_ptr,
		const BaseO3CPUParams &	params )

Constructs an IQ.

Definition at line 87 of file inst_queue.cc.

References commitToIEWDelay, cpu, dependGraph, DPRINTF, fuPool, iewStage, iqIOStats, iqPolicy, iqStats, maxEntries, gem5::o3::MaxThreads, memDepUnit, numEntries, numPhysRegs, numThreads, regScoreboard, resetState(), totalWidth, gem5::VecElemClass, and gem5::VecRegClass.

Referenced by gem5::o3::InstructionQueue::FUCompletion::FUCompletion().

◆ ~InstructionQueue()

gem5::o3::InstructionQueue::~InstructionQueue ( )

Destructs the IQ.

Definition at line 165 of file inst_queue.cc.

References gem5::cprintf(), and dependGraph.

Member Function Documentation

◆ addIfReady()

void gem5::o3::InstructionQueue::addIfReady ( const DynInstPtr & inst )

private

Moves an instruction to the ready queue if it is ready.

Definition at line 1429 of file inst_queue.cc.

References addToOrderList(), DPRINTF, listOrder, memDepUnit, queueOnList, readyInsts, and readyIt.

Referenced by insert(), scheduleNonSpec(), and wakeDependents().

◆ addReadyMemInst()

void gem5::o3::InstructionQueue::addReadyMemInst ( const DynInstPtr & ready_inst )

Adds a ready memory instruction to the ready list.

Definition at line 1074 of file inst_queue.cc.

References addToOrderList(), DPRINTF, listOrder, queueOnList, readyInsts, and readyIt.

Referenced by scheduleReadyInsts().

◆ addToDependents()

bool gem5::o3::InstructionQueue::addToDependents ( const DynInstPtr & new_inst )

private

Adds an instruction to the dependency graph, as a consumer.

Definition at line 1347 of file inst_queue.cc.

References gem5::PhysRegId::className(), dependGraph, DPRINTF, gem5::PhysRegId::flatIndex(), gem5::PhysRegId::index(), gem5::PhysRegId::isFixedMapping(), and regScoreboard.

Referenced by insert().

◆ addToOrderList()

void gem5::o3::InstructionQueue::addToOrderList ( OpClass op_class )

private

Add an op class to the age order list.

Definition at line 673 of file inst_queue.cc.

References listOrder, gem5::o3::InstructionQueue::ListOrderEntry::oldestInst, queueOnList, gem5::o3::InstructionQueue::ListOrderEntry::queueType, readyInsts, and readyIt.

Referenced by addIfReady(), and addReadyMemInst().

◆ addToProducers()

void gem5::o3::InstructionQueue::addToProducers ( const DynInstPtr & new_inst )

private

Adds an instruction to the dependency graph, as a producer.

Definition at line 1394 of file inst_queue.cc.

References gem5::PhysRegId::className(), dependGraph, gem5::PhysRegId::flatIndex(), gem5::PhysRegId::index(), gem5::PhysRegId::isFixedMapping(), panic, and regScoreboard.

Referenced by insert(), insertNonSpec(), and recordProducer().

◆ blockMemInst()

void gem5::o3::InstructionQueue::blockMemInst ( const DynInstPtr & blocked_inst )

Defers a memory instruction when it is cache blocked.

Definition at line 1121 of file inst_queue.cc.

References blockedMemInsts, and DPRINTF.

◆ cacheUnblocked()

void gem5::o3::InstructionQueue::cacheUnblocked ( )

Notify instruction queue that a previous blockage has resolved.

Definition at line 1138 of file inst_queue.cc.

References blockedMemInsts, cpu, DPRINTF, and retryMemInsts.

◆ commit()

void gem5::o3::InstructionQueue::commit	(	const InstSeqNum &	inst,
		ThreadID	tid = 0 )

Commits all instructions up to and including the given sequence number, for a specific thread.

Definition at line 956 of file inst_queue.cc.

References countInsts(), DPRINTF, freeEntries, instList, and numEntries.

◆ countInsts()

int gem5::o3::InstructionQueue::countInsts ( )

private

Debugging function to count how many entries are in the IQ.

It does a linear walk through the instructions, so do not call this function during normal execution.

Definition at line 1468 of file inst_queue.cc.

References freeEntries, and numEntries.

Referenced by commit(), insert(), and insertNonSpec().

◆ deferMemInst()

void gem5::o3::InstructionQueue::deferMemInst ( const DynInstPtr & deferred_inst )

Defers a memory instruction when its DTB translation incurs a hw page table walk.

Definition at line 1115 of file inst_queue.cc.

References deferredMemInsts.

◆ doSquash()

void gem5::o3::InstructionQueue::doSquash ( ThreadID tid )

private

Does the actual squashing.

Definition at line 1198 of file inst_queue.cc.

References count, dependGraph, DPRINTF, gem5::PhysRegId::flatIndex(), freeEntries, instList, iqIOStats, iqStats, gem5::PhysRegId::isFixedMapping(), gem5::NoFault, nonSpecInsts, and squashedSeqNum.

Referenced by squash().

◆ drainSanityCheck()

void gem5::o3::InstructionQueue::drainSanityCheck ( ) const

Perform sanity checks after a drain.

Definition at line 465 of file inst_queue.cc.

References dependGraph, drainSanityCheck(), instsToExecute, memDepUnit, and numThreads.

Referenced by drainSanityCheck().

◆ dumpInsts()

void gem5::o3::InstructionQueue::dumpInsts ( )

private

Debugging function to dump out all instructions that are in the IQ.

Definition at line 1516 of file inst_queue.cc.

References gem5::cprintf(), instList, instsToExecute, and numThreads.

◆ dumpLists()

void gem5::o3::InstructionQueue::dumpLists ( )

private

Debugging function to dump all the list sizes, as well as print out the list of nonspeculative instructions.

Should not be used in any other capacity, but it has no harmful sideaffects.

Definition at line 1474 of file inst_queue.cc.

References gem5::cprintf(), gem5::ArmISA::i, listOrder, nonSpecInsts, gem5::Num_OpClasses, and readyInsts.

◆ entryAmount()

int gem5::o3::InstructionQueue::entryAmount ( ThreadID num_threads )

Number of entries needed for given amount of threads.

Definition at line 480 of file inst_queue.cc.

References iqPolicy, and numEntries.

◆ getBlockedMemInstToExecute()

DynInstPtr gem5::o3::InstructionQueue::getBlockedMemInstToExecute ( )

Gets a memory instruction that was blocked on the cache.

NULL if none available.

Definition at line 1162 of file inst_queue.cc.

References retryMemInsts.

Referenced by scheduleReadyInsts().

◆ getCount()

unsigned gem5::o3::InstructionQueue::getCount ( ThreadID tid )

inline

Returns the number of used entries for a thread.

Definition at line 278 of file inst_queue.hh.

References count.

◆ getDeferredMemInstToExecute()

DynInstPtr gem5::o3::InstructionQueue::getDeferredMemInstToExecute ( )

Gets a memory instruction that was referred due to a delayed DTB translation if it is now ready to execute.

NULL if none available.

Definition at line 1148 of file inst_queue.cc.

References deferredMemInsts.

Referenced by scheduleReadyInsts().

◆ getInstToExecute()

DynInstPtr gem5::o3::InstructionQueue::getInstToExecute ( )

Returns the oldest scheduled instruction, and removes it from the list of instructions waiting to execute.

Definition at line 657 of file inst_queue.cc.

References instsToExecute, and iqIOStats.

◆ hasReadyInsts()

bool gem5::o3::InstructionQueue::hasReadyInsts ( )

Returns if there are any ready instructions in the IQ.

Definition at line 542 of file inst_queue.cc.

References gem5::ArmISA::i, listOrder, gem5::Num_OpClasses, and readyInsts.

◆ insert()

void gem5::o3::InstructionQueue::insert ( const DynInstPtr & new_inst )

Inserts a new instruction into the IQ.

Definition at line 558 of file inst_queue.cc.

References addIfReady(), addToDependents(), addToProducers(), count, countInsts(), DPRINTF, freeEntries, instList, iqIOStats, iqStats, memDepUnit, and numEntries.

◆ insertBarrier()

void gem5::o3::InstructionQueue::insertBarrier ( const DynInstPtr & barr_inst )

Inserts a memory or write barrier into the IQ to make sure loads and stores are ordered properly.

Definition at line 649 of file inst_queue.cc.

References insertNonSpec(), and memDepUnit.

◆ insertNonSpec()

void gem5::o3::InstructionQueue::insertNonSpec ( const DynInstPtr & new_inst )

Inserts a new, non-speculative instruction into the IQ.

Definition at line 603 of file inst_queue.cc.

References addToProducers(), count, countInsts(), DPRINTF, freeEntries, instList, iqIOStats, iqStats, memDepUnit, nonSpecInsts, and numEntries.

Referenced by insertBarrier().

◆ isDrained()

bool gem5::o3::InstructionQueue::isDrained ( ) const

Determine if we are drained.

Definition at line 453 of file inst_queue.cc.

References dependGraph, instsToExecute, isDrained(), memDepUnit, numThreads, and wbOutstanding.

Referenced by isDrained().

◆ isFull() [1/2]

bool gem5::o3::InstructionQueue::isFull ( )

Returns whether or not the IQ is full.

Definition at line 522 of file inst_queue.cc.

References freeEntries.

◆ isFull() [2/2]

bool gem5::o3::InstructionQueue::isFull ( ThreadID tid )

Returns whether or not the IQ is full for a specific thread.

Definition at line 532 of file inst_queue.cc.

References numFreeEntries().

◆ moveToYoungerInst()

void gem5::o3::InstructionQueue::moveToYoungerInst ( ListOrderIt age_order_it )

private

Called when the oldest instruction has been removed from a ready queue; this places that ready queue into the proper spot in the age order list.

Definition at line 699 of file inst_queue.cc.

References listOrder, gem5::o3::InstructionQueue::ListOrderEntry::oldestInst, gem5::o3::InstructionQueue::ListOrderEntry::queueType, readyInsts, and readyIt.

Referenced by scheduleReadyInsts().

◆ name()

std::string gem5::o3::InstructionQueue::name ( ) const

Returns the name of the IQ.

Definition at line 175 of file inst_queue.cc.

References cpu.

◆ numFreeEntries() [1/2]

unsigned gem5::o3::InstructionQueue::numFreeEntries ( )

Returns total number of free entries.

Definition at line 508 of file inst_queue.cc.

References freeEntries.

Referenced by isFull().

◆ numFreeEntries() [2/2]

unsigned gem5::o3::InstructionQueue::numFreeEntries ( ThreadID tid )

Returns number of free entries for a thread.

Definition at line 514 of file inst_queue.cc.

References count, and maxEntries.

◆ printInsts()

void gem5::o3::InstructionQueue::printInsts ( )

Debug function to print all instructions.

◆ processFUCompletion()

void gem5::o3::InstructionQueue::processFUCompletion	(	const DynInstPtr &	inst,
		int	fu_idx )

Process FU completion event.

Definition at line 724 of file inst_queue.cc.

References cpu, DPRINTF, fuPool, iewStage, instsToExecute, issueToExecuteQueue, and wbOutstanding.

◆ recordProducer()

void gem5::o3::InstructionQueue::recordProducer ( const DynInstPtr & inst )

inline

Records the instruction as the producer of a register without adding it to the rest of the IQ.

Definition at line 215 of file inst_queue.hh.

References addToProducers().

◆ replayMemInst()

void gem5::o3::InstructionQueue::replayMemInst ( const DynInstPtr & replay_inst )

Replays a memory instruction.

It must be rescheduled first.

Definition at line 1109 of file inst_queue.cc.

References memDepUnit.

◆ rescheduleMemInst()

void gem5::o3::InstructionQueue::rescheduleMemInst ( const DynInstPtr & resched_inst )

Reschedules a memory instruction.

It will be ready to issue once replayMemInst() is called.

Definition at line 1096 of file inst_queue.cc.

References DPRINTF, and memDepUnit.

◆ resetEntries()

void gem5::o3::InstructionQueue::resetEntries ( )

Resets max entries for all threads.

Definition at line 491 of file inst_queue.cc.

References activeThreads, iqPolicy, maxEntries, numEntries, and numThreads.

◆ resetState()

void gem5::o3::InstructionQueue::resetState ( )

Resets all instruction queue state.

Definition at line 394 of file inst_queue.cc.

References blockedMemInsts, count, deferredMemInsts, freeEntries, gem5::ArmISA::i, instList, listOrder, gem5::o3::MaxThreads, nonSpecInsts, gem5::Num_OpClasses, numEntries, numPhysRegs, queueOnList, readyInsts, readyIt, regScoreboard, retryMemInsts, squashedSeqNum, and wbOutstanding.

Referenced by InstructionQueue(), and takeOverFrom().

◆ retryMemInst()

void gem5::o3::InstructionQueue::retryMemInst ( const DynInstPtr & retry_inst )

Retries a memory instruction in the next cycle.

Definition at line 1132 of file inst_queue.cc.

References retryMemInsts.

◆ scheduleNonSpec()

void gem5::o3::InstructionQueue::scheduleNonSpec ( const InstSeqNum & inst )

Schedules a single specific non-speculative instruction.

Definition at line 929 of file inst_queue.cc.

References addIfReady(), DPRINTF, memDepUnit, and nonSpecInsts.

◆ scheduleReadyInsts()

void gem5::o3::InstructionQueue::scheduleReadyInsts ( )

Schedules ready instructions, adding the ready ones (oldest first) to the queue to execute.

Definition at line 747 of file inst_queue.cc.

References addReadyMemInst(), count, cpu, gem5::curTick(), deferredMemInsts, DPRINTF, freeEntries, fuPool, getBlockedMemInstToExecute(), getDeferredMemInstToExecute(), instsToExecute, iqIOStats, iqStats, issueToExecuteQueue, listOrder, memDepUnit, moveToYoungerInst(), gem5::o3::FUPool::NoCapableFU, gem5::o3::FUPool::NoFreeFU, gem5::o3::FUPool::NoNeedFU, queueOnList, readyInsts, readyIt, retryMemInsts, gem5::o3::InstructionQueue::FUCompletion::setFreeFU(), gem5::o3::IssueStruct::size, totalWidth, and wbOutstanding.

◆ setActiveThreads()

void gem5::o3::InstructionQueue::setActiveThreads ( std::list< ThreadID > * at_ptr )

Sets active threads list.

Definition at line 433 of file inst_queue.cc.

References activeThreads.

◆ setIssueToExecuteQueue()

void gem5::o3::InstructionQueue::setIssueToExecuteQueue ( TimeBuffer< IssueStruct > * i2eQueue )

Sets the timer buffer between issue and execute.

Definition at line 439 of file inst_queue.cc.

References issueToExecuteQueue.

◆ setTimeBuffer()

void gem5::o3::InstructionQueue::setTimeBuffer ( TimeBuffer< TimeStruct > * tb_ptr )

Sets the global time buffer.

Definition at line 445 of file inst_queue.cc.

References commitToIEWDelay, fromCommit, and timeBuffer.

◆ squash()

void gem5::o3::InstructionQueue::squash ( ThreadID tid )

Squashes instructions for a thread.

Squashing information is obtained from the time buffer.

Definition at line 1182 of file inst_queue.cc.

References doSquash(), DPRINTF, fromCommit, memDepUnit, and squashedSeqNum.

◆ takeOverFrom()

void gem5::o3::InstructionQueue::takeOverFrom ( )

Takes over execution from another CPU's thread.

Definition at line 474 of file inst_queue.cc.

References resetState().

◆ violation()

void gem5::o3::InstructionQueue::violation	(	const DynInstPtr &	store,
		const DynInstPtr &	faulting_load )

Indicates an ordering violation between a store and a load.

Definition at line 1174 of file inst_queue.cc.

References iqIOStats, and memDepUnit.

◆ wakeDependents()

int gem5::o3::InstructionQueue::wakeDependents ( const DynInstPtr & completed_inst )

Wakes all dependents of a completed instruction.

Definition at line 973 of file inst_queue.cc.

References addIfReady(), gem5::PhysRegId::className(), count, gem5::curTick(), gem5::PhysRegId::decrNumPinnedWritesToComplete(), dependGraph, DPRINTF, gem5::PhysRegId::flatIndex(), freeEntries, gem5::PhysRegId::getNumPinnedWritesToComplete(), gem5::PhysRegId::index(), iqIOStats, gem5::PhysRegId::isFixedMapping(), gem5::PhysRegId::isPinned(), memDepUnit, and regScoreboard.

Member Data Documentation

◆ activeThreads

std::list<ThreadID>* gem5::o3::InstructionQueue::activeThreads

private

Pointer to list of active threads.

Definition at line 421 of file inst_queue.hh.

Referenced by resetEntries(), and setActiveThreads().

◆ blockedMemInsts

std::list<DynInstPtr> gem5::o3::InstructionQueue::blockedMemInsts

private

List of instructions that have been cache blocked.

Definition at line 335 of file inst_queue.hh.

Referenced by blockMemInst(), cacheUnblocked(), and resetState().

◆ commitToIEWDelay

Cycles gem5::o3::InstructionQueue::commitToIEWDelay

private

Delay between commit stage and the IQ.

Todo: : Make there be a distinction between the delays within IEW.

Definition at line 447 of file inst_queue.hh.

Referenced by InstructionQueue(), and setTimeBuffer().

◆ count

unsigned gem5::o3::InstructionQueue::count[MaxThreads]

private

Per Thread IQ count.

Definition at line 424 of file inst_queue.hh.

Referenced by doSquash(), getCount(), insert(), insertNonSpec(), numFreeEntries(), resetState(), scheduleReadyInsts(), and wakeDependents().

◆ cpu

CPU* gem5::o3::InstructionQueue::cpu

private

Pointer to the CPU.

Definition at line 292 of file inst_queue.hh.

Referenced by cacheUnblocked(), InstructionQueue(), gem5::o3::InstructionQueue::IQStats::IQStats(), name(), processFUCompletion(), and scheduleReadyInsts().

◆ dcacheInterface

memory::MemInterface* gem5::o3::InstructionQueue::dcacheInterface

private

Cache interface.

Definition at line 295 of file inst_queue.hh.

◆ deferredMemInsts

std::list<DynInstPtr> gem5::o3::InstructionQueue::deferredMemInsts

private

List of instructions waiting for their DTB translation to complete (hw page table walk in progress).

Definition at line 332 of file inst_queue.hh.

Referenced by deferMemInst(), getDeferredMemInstToExecute(), resetState(), and scheduleReadyInsts().

◆ dependGraph

DependencyGraph<DynInstPtr> gem5::o3::InstructionQueue::dependGraph

private

Definition at line 408 of file inst_queue.hh.

Referenced by addToDependents(), addToProducers(), doSquash(), drainSanityCheck(), InstructionQueue(), isDrained(), wakeDependents(), and ~InstructionQueue().

◆ freeEntries

unsigned gem5::o3::InstructionQueue::freeEntries

private

Number of free IQ entries left.

Definition at line 430 of file inst_queue.hh.

Referenced by commit(), countInsts(), doSquash(), insert(), insertNonSpec(), isFull(), numFreeEntries(), resetState(), scheduleReadyInsts(), and wakeDependents().

◆ fromCommit

TimeBuffer<TimeStruct>::wire gem5::o3::InstructionQueue::fromCommit

private

Wire to read information from timebuffer.

Definition at line 314 of file inst_queue.hh.

Referenced by setTimeBuffer(), and squash().

◆ fuPool

FUPool* gem5::o3::InstructionQueue::fuPool

private

Function unit pool.

Definition at line 317 of file inst_queue.hh.

Referenced by InstructionQueue(), processFUCompletion(), and scheduleReadyInsts().

◆ iewStage

IEW* gem5::o3::InstructionQueue::iewStage

private

Pointer to IEW stage.

Definition at line 298 of file inst_queue.hh.

Referenced by InstructionQueue(), and processFUCompletion().

◆ instList

std::list<DynInstPtr> gem5::o3::InstructionQueue::instList[MaxThreads]

private

List of all the instructions in the IQ (some of which may be issued).

Definition at line 324 of file inst_queue.hh.

Referenced by commit(), doSquash(), dumpInsts(), insert(), insertNonSpec(), and resetState().

◆ instsToExecute

std::list<DynInstPtr> gem5::o3::InstructionQueue::instsToExecute

private

List of instructions that are ready to be executed.

Definition at line 327 of file inst_queue.hh.

Referenced by drainSanityCheck(), dumpInsts(), getInstToExecute(), isDrained(), processFUCompletion(), and scheduleReadyInsts().

◆ iqIOStats

gem5::o3::InstructionQueue::IQIOStats gem5::o3::InstructionQueue::iqIOStats

Referenced by doSquash(), getInstToExecute(), insert(), insertNonSpec(), InstructionQueue(), scheduleReadyInsts(), violation(), and wakeDependents().

◆ iqPolicy

SMTQueuePolicy gem5::o3::InstructionQueue::iqPolicy

private

IQ sharing policy for SMT.

Definition at line 415 of file inst_queue.hh.

Referenced by entryAmount(), InstructionQueue(), and resetEntries().

◆ iqStats

gem5::o3::InstructionQueue::IQStats gem5::o3::InstructionQueue::iqStats

private

Referenced by doSquash(), insert(), insertNonSpec(), InstructionQueue(), and scheduleReadyInsts().

◆ issueToExecuteQueue

TimeBuffer<IssueStruct>* gem5::o3::InstructionQueue::issueToExecuteQueue

private

The queue to the execute stage.

Issued instructions will be written into it.

Definition at line 308 of file inst_queue.hh.

Referenced by processFUCompletion(), scheduleReadyInsts(), and setIssueToExecuteQueue().

◆ listOrder

std::list<ListOrderEntry> gem5::o3::InstructionQueue::listOrder

private

List that contains the age order of the oldest instruction of each ready queue.

Used to select the oldest instruction available among op classes.

Todo: : Might be better to just move these entries around instead of creating new ones every time the position changes due to an instruction issuing. Not sure std::list supports this.

Definition at line 387 of file inst_queue.hh.

Referenced by addIfReady(), addReadyMemInst(), addToOrderList(), dumpLists(), hasReadyInsts(), moveToYoungerInst(), resetState(), and scheduleReadyInsts().

◆ maxEntries

unsigned gem5::o3::InstructionQueue::maxEntries[MaxThreads]

private

Max IQ Entries Per Thread.

Definition at line 427 of file inst_queue.hh.

Referenced by InstructionQueue(), numFreeEntries(), and resetEntries().

◆ memDepUnit

MemDepUnit gem5::o3::InstructionQueue::memDepUnit[MaxThreads]

private

The memory dependence unit, which tracks/predicts memory dependences between instructions.

Definition at line 303 of file inst_queue.hh.

Referenced by addIfReady(), drainSanityCheck(), insert(), insertBarrier(), insertNonSpec(), InstructionQueue(), isDrained(), replayMemInst(), rescheduleMemInst(), scheduleNonSpec(), scheduleReadyInsts(), squash(), violation(), and wakeDependents().

◆ nonSpecInsts

std::map<InstSeqNum, DynInstPtr> gem5::o3::InstructionQueue::nonSpecInsts

private

List of non-speculative instructions that will be scheduled once the IQ gets a signal from commit.

While it's redundant to have the key be a part of the value (the sequence number is stored inside of DynInst), when these instructions are woken up only the sequence number will be available. Thus it is most efficient to be able to search by the sequence number alone.

Definition at line 369 of file inst_queue.hh.

Referenced by doSquash(), dumpLists(), insertNonSpec(), resetState(), and scheduleNonSpec().

◆ numEntries

unsigned gem5::o3::InstructionQueue::numEntries

private

The number of entries in the instruction queue.

Definition at line 433 of file inst_queue.hh.

Referenced by commit(), countInsts(), entryAmount(), insert(), insertNonSpec(), InstructionQueue(), resetEntries(), and resetState().

◆ numPhysRegs

unsigned gem5::o3::InstructionQueue::numPhysRegs

private

The number of physical registers in the CPU.

Definition at line 439 of file inst_queue.hh.

Referenced by InstructionQueue(), and resetState().

◆ numThreads

ThreadID gem5::o3::InstructionQueue::numThreads

private

Number of Total Threads.

Definition at line 418 of file inst_queue.hh.

Referenced by drainSanityCheck(), dumpInsts(), InstructionQueue(), isDrained(), and resetEntries().

◆ queueOnList

bool gem5::o3::InstructionQueue::queueOnList[Num_OpClasses]

private

Tracks if each ready queue is on the age order list.

Definition at line 392 of file inst_queue.hh.

Referenced by addIfReady(), addReadyMemInst(), addToOrderList(), resetState(), and scheduleReadyInsts().

◆ readyInsts

ReadyInstQueue gem5::o3::InstructionQueue::readyInsts[Num_OpClasses]

private

List of ready instructions, per op class.

They are separated by op class to allow for easy mapping to FUs.

Definition at line 360 of file inst_queue.hh.

Referenced by addIfReady(), addReadyMemInst(), addToOrderList(), dumpLists(), hasReadyInsts(), moveToYoungerInst(), resetState(), and scheduleReadyInsts().

◆ readyIt

ListOrderIt gem5::o3::InstructionQueue::readyIt[Num_OpClasses]

private

Iterators of each ready queue.

Points to their spot in the age order list.

Definition at line 397 of file inst_queue.hh.

Referenced by addIfReady(), addReadyMemInst(), addToOrderList(), moveToYoungerInst(), resetState(), and scheduleReadyInsts().

◆ regScoreboard

std::vector<bool> gem5::o3::InstructionQueue::regScoreboard

private

A cache of the recently woken registers.

It is 1 if the register has been woken up recently, and 0 if the register has been added to the dependency graph and has not yet received its value. It is basically a secondary scoreboard, and should pretty much mirror the scoreboard that exists in the rename map.

Definition at line 458 of file inst_queue.hh.

Referenced by addToDependents(), addToProducers(), InstructionQueue(), resetState(), and wakeDependents().

◆ retryMemInsts

std::list<DynInstPtr> gem5::o3::InstructionQueue::retryMemInsts

private

List of instructions that were cache blocked, but a retry has been seen since, so they can now be retried.

May fail again go on the blocked list.

Definition at line 340 of file inst_queue.hh.

Referenced by cacheUnblocked(), getBlockedMemInstToExecute(), resetState(), retryMemInst(), and scheduleReadyInsts().

◆ squashedSeqNum

InstSeqNum gem5::o3::InstructionQueue::squashedSeqNum[MaxThreads]

private

The sequence number of the squashed instruction.

Definition at line 450 of file inst_queue.hh.

Referenced by doSquash(), resetState(), and squash().

◆ timeBuffer

TimeBuffer<TimeStruct>* gem5::o3::InstructionQueue::timeBuffer

private

The backwards time buffer.

Definition at line 311 of file inst_queue.hh.

Referenced by setTimeBuffer().

◆ totalWidth

unsigned gem5::o3::InstructionQueue::totalWidth

private

The total number of instructions that can be issued in one cycle.

Definition at line 436 of file inst_queue.hh.

Referenced by InstructionQueue(), and scheduleReadyInsts().

◆ wbOutstanding

int gem5::o3::InstructionQueue::wbOutstanding

private

Number of instructions currently in flight to FUs.

Definition at line 442 of file inst_queue.hh.

Referenced by isDrained(), processFUCompletion(), resetState(), and scheduleReadyInsts().

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

cpu/o3/inst_queue.hh
cpu/o3/inst_queue.cc

Classes

Public Types

Public Member Functions

Public Attributes

Private Types

Private Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ ListIt

◆ ListOrderIt

◆ NonSpecMapIt

◆ ReadyInstQueue

Constructor & Destructor Documentation

◆ InstructionQueue()

◆ ~InstructionQueue()

Member Function Documentation

◆ addIfReady()

◆ addReadyMemInst()

◆ addToDependents()

◆ addToOrderList()

◆ addToProducers()

◆ blockMemInst()

◆ cacheUnblocked()

◆ commit()

◆ countInsts()

◆ deferMemInst()

◆ doSquash()

◆ drainSanityCheck()

◆ dumpInsts()

◆ dumpLists()

◆ entryAmount()

◆ getBlockedMemInstToExecute()

◆ getCount()

◆ getDeferredMemInstToExecute()

◆ getInstToExecute()

◆ hasReadyInsts()

◆ insert()

◆ insertBarrier()

◆ insertNonSpec()

◆ isDrained()

◆ isFull() [1/2]

◆ isFull() [2/2]

◆ moveToYoungerInst()

◆ name()

◆ numFreeEntries() [1/2]

◆ numFreeEntries() [2/2]

◆ printInsts()

◆ processFUCompletion()

◆ recordProducer()

◆ replayMemInst()

◆ rescheduleMemInst()

◆ resetEntries()

◆ resetState()

◆ retryMemInst()

◆ scheduleNonSpec()

◆ scheduleReadyInsts()

◆ setActiveThreads()

◆ setIssueToExecuteQueue()

◆ setTimeBuffer()

◆ squash()

◆ takeOverFrom()

◆ violation()

◆ wakeDependents()

Member Data Documentation

◆ activeThreads

◆ blockedMemInsts

◆ commitToIEWDelay

◆ count

◆ cpu

◆ dcacheInterface

◆ deferredMemInsts

◆ dependGraph

◆ freeEntries

◆ fromCommit

◆ fuPool

◆ iewStage

◆ instList

◆ instsToExecute

◆ iqIOStats