ROB class. More...

#include <rob.hh>

Public Types
enum	Status { Running, Idle, ROBSquashing }
	Possible ROB statuses. More...

enum	ROBPolicy { Dynamic, Partitioned, Threshold }
	SMT ROB Sharing Policy. More...

typedef Impl::O3CPU	O3CPU

typedef Impl::DynInstPtr	DynInstPtr

typedef std::pair< RegIndex, PhysRegIndex >	UnmapInfo

typedef std::list< DynInstPtr > ::iterator	InstIt

Public Member Functions
	ROB (O3CPU _cpu, DerivO3CPUParams params)
	ROB constructor. More...

std::string	name () const

void	setActiveThreads (std::list< ThreadID > *at_ptr)
	Sets pointer to the list of active threads. More...

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

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

void	insertInst (DynInstPtr &inst)
	Function to insert an instruction into the ROB. More...

DynInstPtr	readHeadInst (ThreadID tid)
	Returns pointer to the head instruction within the ROB. More...

DynInstPtr	findInst (ThreadID tid, InstSeqNum squash_inst)
	Returns a pointer to the instruction with the given sequence if it is in the ROB. More...

DynInstPtr	readTailInst (ThreadID tid)
	Returns pointer to the tail instruction within the ROB. More...

void	retireHead (ThreadID tid)
	Retires the head instruction, removing it from the ROB. More...

bool	isHeadReady (ThreadID tid)
	Is the oldest instruction across all threads ready. More...

bool	canCommit ()
	Is there any commitable head instruction across all threads ready. More...

void	resetEntries ()
	Re-adjust ROB partitioning. More...

int	entryAmount (ThreadID num_threads)
	Number of entries needed For 'num_threads' amount of threads. More...

unsigned	numFreeEntries ()
	Returns the number of total free entries in the ROB. More...

unsigned	numFreeEntries (ThreadID tid)
	Returns the number of free entries in a specific ROB paritition. More...

unsigned	getMaxEntries (ThreadID tid)
	Returns the maximum number of entries for a specific thread. More...

unsigned	getThreadEntries (ThreadID tid)
	Returns the number of entries being used by a specific thread. More...

bool	isFull ()
	Returns if the ROB is full. More...

bool	isFull (ThreadID tid)
	Returns if a specific thread's partition is full. More...

bool	isEmpty () const
	Returns if the ROB is empty. More...

bool	isEmpty (ThreadID tid) const
	Returns if a specific thread's partition is empty. More...

void	doSquash (ThreadID tid)
	Executes the squash, marking squashed instructions. More...

void	squash (InstSeqNum squash_num, ThreadID tid)
	Squashes all instructions younger than the given sequence number for the specific thread. More...

void	updateHead ()
	Updates the head instruction with the new oldest instruction. More...

void	updateTail ()
	Updates the tail instruction with the new youngest instruction. More...

bool	isDoneSquashing (ThreadID tid) const
	Reads the PC of the oldest head instruction. More...

bool	isDoneSquashing ()
	Checks if the ROB is still in the process of squashing instructions for any thread. More...

int	countInsts ()
	This is more of a debugging function than anything. More...

int	countInsts (ThreadID tid)
	This is more of a debugging function than anything. More...

void	regStats ()
	Registers statistics. More...

Public Attributes
InstIt	tail
	Iterator pointing to the instruction which is the last instruction in the ROB. More...

InstIt	head
	Iterator pointing to the instruction which is the first instruction in in the ROB. More...

int	numInstsInROB
	Number of instructions in the ROB. More...

DynInstPtr	dummyInst
	Dummy instruction returned if there are no insts left. More...

Protected Types
typedef TheISA::RegIndex	RegIndex

Private Member Functions
void	resetState ()
	Reset the ROB state. More...

Private Attributes
Status	robStatus [Impl::MaxThreads]
	Per-thread ROB status. More...

ROBPolicy	robPolicy
	ROB resource sharing policy for SMT mode. More...

O3CPU *	cpu
	Pointer to the CPU. More...

std::list< ThreadID > *	activeThreads
	Active Threads in CPU. More...

unsigned	numEntries
	Number of instructions in the ROB. More...

unsigned	threadEntries [Impl::MaxThreads]
	Entries Per Thread. More...

unsigned	maxEntries [Impl::MaxThreads]
	Max Insts a Thread Can Have in the ROB. More...

std::list< DynInstPtr >	instList [Impl::MaxThreads]
	ROB List of Instructions. More...

unsigned	squashWidth
	Number of instructions that can be squashed in a single cycle. More...

InstIt	squashIt [Impl::MaxThreads]
	Iterator used for walking through the list of instructions when squashing. More...

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

bool	doneSquashing [Impl::MaxThreads]
	Is the ROB done squashing. More...

ThreadID	numThreads
	Number of active threads. More...

Stats::Scalar	robReads

Stats::Scalar	robWrites

Detailed Description

template<class Impl>
class ROB< Impl >

ROB class.

The ROB is largely what drives squashing.

Definition at line 61 of file rob.hh.

Member Typedef Documentation

template<class Impl >

typedef Impl::DynInstPtr ROB< Impl >::DynInstPtr

Definition at line 68 of file rob.hh.

template<class Impl >

typedef std::list<DynInstPtr>::iterator ROB< Impl >::InstIt

Definition at line 71 of file rob.hh.

template<class Impl >

typedef Impl::O3CPU ROB< Impl >::O3CPU

Definition at line 67 of file rob.hh.

template<class Impl >

typedef TheISA::RegIndex ROB< Impl >::RegIndex

protected

Definition at line 64 of file rob.hh.

template<class Impl >

typedef std::pair<RegIndex, PhysRegIndex> ROB< Impl >::UnmapInfo

Definition at line 70 of file rob.hh.

Member Enumeration Documentation

template<class Impl >

enum ROB::ROBPolicy

SMT ROB Sharing Policy.

Enumerator
Dynamic
Partitioned
Threshold

Definition at line 81 of file rob.hh.

template<class Impl >

enum ROB::Status

Possible ROB statuses.

Enumerator
Running
Idle
ROBSquashing

Definition at line 74 of file rob.hh.

Constructor & Destructor Documentation

template<class Impl >

ROB< Impl >::ROB	(	O3CPU *	_cpu,
		DerivO3CPUParams *	params
	)

ROB constructor.

Parameters

_cpu	The cpu object pointer.
params	The cpu params including several ROB-specific parameters.

Definition at line 57 of file rob_impl.hh.

References DPRINTF, ROB< Impl >::Dynamic, ROB< Impl >::maxEntries, ROB< Impl >::numEntries, ROB< Impl >::numThreads, ROB< Impl >::Partitioned, ROB< Impl >::resetState(), ROB< Impl >::robPolicy, and ROB< Impl >::Threshold.

Member Function Documentation

template<class Impl >

bool ROB< Impl >::canCommit ( )

Is there any commitable head instruction across all threads ready.

Definition at line 297 of file rob_impl.hh.

template<class Impl >

int ROB< Impl >::countInsts ( )

This is more of a debugging function than anything.

Use numInstsInROB to get the instructions in the ROB unless you are double checking that variable.

Definition at line 193 of file rob_impl.hh.

References Stats::total.

template<class Impl >

int ROB< Impl >::countInsts ( ThreadID tid )

This is more of a debugging function than anything.

Use threadEntries to get the instructions in the ROB unless you are double checking that variable.

Definition at line 205 of file rob_impl.hh.

template<class Impl >

void ROB< Impl >::doSquash ( ThreadID tid )

Executes the squash, marking squashed instructions.

Definition at line 330 of file rob_impl.hh.

References DPRINTF.

template<class Impl >

void ROB< Impl >::drainSanityCheck ( ) const

Perform sanity checks after a drain.

Definition at line 144 of file rob_impl.hh.

template<class Impl >

int ROB< Impl >::entryAmount ( ThreadID num_threads )

Number of entries needed For 'num_threads' amount of threads.

Definition at line 182 of file rob_impl.hh.

template<class Impl >

Impl::DynInstPtr ROB< Impl >::findInst	(	ThreadID	tid,
		InstSeqNum	squash_inst
	)

Returns a pointer to the instruction with the given sequence if it is in the ROB.

Definition at line 556 of file rob_impl.hh.

template<class Impl >

unsigned ROB< Impl >::getMaxEntries ( ThreadID tid )

inline

Returns the maximum number of entries for a specific thread.

Definition at line 180 of file rob.hh.

References ROB< Impl >::maxEntries.

template<class Impl >

unsigned ROB< Impl >::getThreadEntries ( ThreadID tid )

inline

Returns the number of entries being used by a specific thread.

Definition at line 184 of file rob.hh.

References ROB< Impl >::threadEntries.

template<class Impl >

void ROB< Impl >::insertInst ( DynInstPtr & inst )

Function to insert an instruction into the ROB.

Note that whatever calls this function must ensure that there is enough space within the ROB for the new instruction.

Parameters

inst	The instruction being inserted into the ROB.

Definition at line 212 of file rob_impl.hh.

References DPRINTF.

template<class Impl >

bool ROB< Impl >::isDoneSquashing ( ThreadID tid ) const

inline

Reads the PC of the oldest head instruction.

Reads the PC of the head instruction of a specific thread. Reads the next PC of the oldest head instruction. Reads the next PC of the head instruction of a specific thread. Reads the sequence number of the oldest head instruction. Reads the sequence number of the head instruction of a specific thread.Reads the PC of the youngest tail instruction. Reads the PC of the tail instruction of a specific thread. Reads the sequence number of the youngest tail instruction. Reads the sequence number of tail instruction of a specific thread. Checks if the ROB is still in the process of squashing instructions.

Return values

Whether or not the ROB is done squashing.

Definition at line 251 of file rob.hh.

References ROB< Impl >::doneSquashing.

template<class Impl >

bool ROB< Impl >::isDoneSquashing ( )

Checks if the ROB is still in the process of squashing instructions for any thread.

template<class Impl >

bool ROB< Impl >::isEmpty ( ) const

inline

Returns if the ROB is empty.

Definition at line 196 of file rob.hh.

References ROB< Impl >::numInstsInROB.

template<class Impl >

bool ROB< Impl >::isEmpty ( ThreadID tid ) const

inline

Returns if a specific thread's partition is empty.

Definition at line 200 of file rob.hh.

References ROB< Impl >::threadEntries.

template<class Impl >

bool ROB< Impl >::isFull ( )

inline

Returns if the ROB is full.

Definition at line 188 of file rob.hh.

References ROB< Impl >::numEntries, and ROB< Impl >::numInstsInROB.

template<class Impl >

bool ROB< Impl >::isFull ( ThreadID tid )

inline

Returns if a specific thread's partition is full.

Definition at line 192 of file rob.hh.

References ROB< Impl >::numEntries, and ROB< Impl >::threadEntries.

template<class Impl >

bool ROB< Impl >::isHeadReady ( ThreadID tid )

Is the oldest instruction across all threads ready.

Is the oldest instruction across a particular thread ready.

Definition at line 285 of file rob_impl.hh.

template<class Impl >

std::string ROB< Impl >::name ( ) const

Definition at line 129 of file rob_impl.hh.

template<class Impl >

unsigned ROB< Impl >::numFreeEntries ( )

Returns the number of total free entries in the ROB.

Definition at line 316 of file rob_impl.hh.

template<class Impl >

unsigned ROB< Impl >::numFreeEntries ( ThreadID tid )

Returns the number of free entries in a specific ROB paritition.

Definition at line 323 of file rob_impl.hh.

template<class Impl >

Impl::DynInstPtr ROB< Impl >::readHeadInst ( ThreadID tid )

Returns pointer to the head instruction within the ROB.

There is no guarantee as to the return value if the ROB is empty.

Return values

Pointer to the DynInst that is at the head of the ROB.Returns a pointer to the head instruction of a specific thread within the ROB.

Returns: Pointer to the DynInst that is at the head of the ROB.

Definition at line 517 of file rob_impl.hh.

template<class Impl >

Impl::DynInstPtr ROB< Impl >::readTailInst ( ThreadID tid )

Returns pointer to the tail instruction within the ROB.

There is no guarantee as to the return value if the ROB is empty.

Return values

Pointer to the DynInst that is at the tail of the ROB.Returns a pointer to the tail instruction of a specific thread within the ROB.

Returns: Pointer to the DynInst that is at the tail of the ROB.

Definition at line 532 of file rob_impl.hh.

template<class Impl >

void ROB< Impl >::regStats ( )

Registers statistics.

Definition at line 542 of file rob_impl.hh.

References name().

template<class Impl >

void ROB< Impl >::resetEntries ( )

Re-adjust ROB partitioning.

Definition at line 160 of file rob_impl.hh.

template<class Impl >

void ROB< Impl >::resetState ( )

private

Reset the ROB state.

Definition at line 111 of file rob_impl.hh.

Referenced by ROB< Impl >::ROB().

template<class Impl >

void ROB< Impl >::retireHead ( ThreadID tid )

Retires the head instruction, removing it from the ROB.

Retires the head instruction of a specific thread, removing it from the ROB.

Definition at line 249 of file rob_impl.hh.

References DPRINTF.

template<class Impl >

void ROB< Impl >::setActiveThreads ( std::list< ThreadID > * at_ptr )

Sets pointer to the list of active threads.

Parameters

at_ptr Pointer to the list of active threads.

Definition at line 136 of file rob_impl.hh.

References DPRINTF.

template<class Impl >

void ROB< Impl >::squash	(	InstSeqNum	squash_num,
		ThreadID	tid
	)

Squashes all instructions younger than the given sequence number for the specific thread.

Definition at line 487 of file rob_impl.hh.

References DPRINTF.

template<class Impl >

void ROB< Impl >::takeOverFrom ( )

Takes over another CPU's thread.

Definition at line 153 of file rob_impl.hh.

template<class Impl >

void ROB< Impl >::updateHead ( )

Updates the head instruction with the new oldest instruction.

Definition at line 407 of file rob_impl.hh.

template<class Impl >

void ROB< Impl >::updateTail ( )

Updates the tail instruction with the new youngest instruction.

Definition at line 449 of file rob_impl.hh.

Member Data Documentation

template<class Impl >

std::list<ThreadID>* ROB< Impl >::activeThreads

private

Active Threads in CPU.

Definition at line 282 of file rob.hh.

template<class Impl >

O3CPU* ROB< Impl >::cpu

private

Pointer to the CPU.

Definition at line 279 of file rob.hh.

template<class Impl >

bool ROB< Impl >::doneSquashing[Impl::MaxThreads]

private

Is the ROB done squashing.

Definition at line 332 of file rob.hh.

Referenced by ROB< Impl >::isDoneSquashing().

template<class Impl >

DynInstPtr ROB< Impl >::dummyInst

Dummy instruction returned if there are no insts left.

Definition at line 325 of file rob.hh.

template<class Impl >

InstIt ROB< Impl >::head

Iterator pointing to the instruction which is the first instruction in in the ROB.

Definition at line 308 of file rob.hh.

template<class Impl >

std::list<DynInstPtr> ROB< Impl >::instList[Impl::MaxThreads]

private

ROB List of Instructions.

Definition at line 294 of file rob.hh.

template<class Impl >

unsigned ROB< Impl >::maxEntries[Impl::MaxThreads]

private

Max Insts a Thread Can Have in the ROB.

Definition at line 291 of file rob.hh.

Referenced by ROB< Impl >::getMaxEntries(), and ROB< Impl >::ROB().

template<class Impl >

unsigned ROB< Impl >::numEntries

private

Number of instructions in the ROB.

Definition at line 285 of file rob.hh.

Referenced by ROB< Impl >::isFull(), and ROB< Impl >::ROB().

template<class Impl >

int ROB< Impl >::numInstsInROB

Number of instructions in the ROB.

Definition at line 322 of file rob.hh.

Referenced by ROB< Impl >::isEmpty(), and ROB< Impl >::isFull().

template<class Impl >

ThreadID ROB< Impl >::numThreads

private

Number of active threads.

Definition at line 335 of file rob.hh.

Referenced by ROB< Impl >::ROB().

template<class Impl >

ROBPolicy ROB< Impl >::robPolicy

private

ROB resource sharing policy for SMT mode.

Definition at line 92 of file rob.hh.

Referenced by ROB< Impl >::ROB().

template<class Impl >

Stats::Scalar ROB< Impl >::robReads

private

Definition at line 338 of file rob.hh.

template<class Impl >

Status ROB< Impl >::robStatus[Impl::MaxThreads]

private

Per-thread ROB status.

Definition at line 89 of file rob.hh.

template<class Impl >

Stats::Scalar ROB< Impl >::robWrites

private

Definition at line 340 of file rob.hh.

template<class Impl >

InstSeqNum ROB< Impl >::squashedSeqNum[Impl::MaxThreads]

private

The sequence number of the squashed instruction.

Definition at line 329 of file rob.hh.

template<class Impl >

InstIt ROB< Impl >::squashIt[Impl::MaxThreads]

private

Iterator used for walking through the list of instructions when squashing.

Used so that there is persistent state between cycles; when squashing, the instructions are marked as squashed but not immediately removed, meaning the tail iterator remains the same before and after a squash. This will always be set to cpu->instList.end() if it is invalid.

Definition at line 318 of file rob.hh.

template<class Impl >

unsigned ROB< Impl >::squashWidth

private

Number of instructions that can be squashed in a single cycle.

Definition at line 297 of file rob.hh.

template<class Impl >

InstIt ROB< Impl >::tail

Iterator pointing to the instruction which is the last instruction in the ROB.

This may at times be invalid (ie when the ROB is empty), however it should never be incorrect.

Definition at line 304 of file rob.hh.

template<class Impl >

unsigned ROB< Impl >::threadEntries[Impl::MaxThreads]

private

Entries Per Thread.

Definition at line 288 of file rob.hh.

Referenced by ROB< Impl >::getThreadEntries(), ROB< Impl >::isEmpty(), and ROB< Impl >::isFull().

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

cpu/o3/rob.hh
cpu/o3/rob_impl.hh

Public Types

Public Member Functions

Public Attributes

Protected Types

Private Member Functions

Private Attributes

Detailed Description

template<class Impl> class ROB< Impl >

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

template<class Impl>
class ROB< Impl >