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Class simtix::pipelined::InstrBuffer

ClassList > simtix > pipelined > InstrBuffer

A instruction buffer.

  • #include <instr_buffer.h>

Inherited by the following classes: simtix::uvm::MockInstrBuffer

Classes

Type Name
struct InstrStream
Represent the instruction stream for a single warp.

Public Functions

Type Name
bool CanEnq (const InstrPtr & instr) const
Check if an instruction can be enqueued.
InstrPtr Deq (uint32_t wid, std::optional< uint32_t > ssw)
Dequeue an instruction from a warp's instruction stream.
void Disable (uint32_t wid)
Disable a warp’s instruction buffer when encountering exceptions.
void Enable (uint32_t wid, uint64_t next_pc)
Initialize each warp’s instruction buffer when doing PipelinedSM::Process .
void Enq (InstrPtr instr)
Enqueue an instruction into the buffer.
void ForEachValidInstrStream (TFunc cb)
Iterate over each valid instruction stream.
InstrBuffer (PipelinedSMImpl * sm, const ArchParam & p=kDefaultArchParam, const PipelinedSM::Param & pp=PipelinedSM::kDefaultParam)
Construct the instruction buffer.
void NotifyCtrlFlowChange (uint32_t wid, uint64_t wpc, std::optional< uint64_t > sswpc)
Notify the buffer of a control flow change (divergence or convergence).
void Reset ()
Reset the entire instruction buffer (all warps).
virtual bool capacious (uint32_t wid, std::optional< uint32_t > ssw) const
Check if the instruction stream can accommodate more instructions.
std::size_t capacity (uint32_t wid) const
Get the instruction buffer capacity for a warp.
bool empty (uint32_t wid, std::optional< uint32_t > ssw) const
Check if the instruction stream is empty.
virtual uint64_t fetch_pc (uint32_t wid, std::optional< uint32_t > ssw) const
Get the current fetch PC.
const InstrPtr & front (uint32_t wid, std::optional< uint32_t > ssw) const
Get the instruction at the front of a warp’s instruction stream.
bool full (uint32_t wid, std::optional< uint32_t > ssw) const
Check if the instruction stream is full.
bool is_diverged (uint32_t wid) const
Check whether the warp has diverged.
uint64_t next_pc (uint32_t wid, std::optional< uint32_t > ssw) const
Get the next PC for the warp’s instruction stream.
void set_fetch_pc (uint32_t wid, std::optional< uint32_t > ssw, uint64_t fetch_pc) const
Set the fetch PC for a given warp.
std::size_t size (uint32_t wid, std::optional< uint32_t > ssw) const
Get the number of instructions currently buffered.
bool valid (uint32_t wid, std::optional< uint32_t > ssw) const
Check whether the instruction stream is valid.
virtual ~InstrBuffer () = default

Protected Attributes

Type Name
std::vector< std::unique_ptr< InstrStream > > buf_
std::size_t capacity_
const uint32_t kFetchWidth
PipelinedSMImpl * sm_

Protected Static Attributes

Type Name
constexpr std::array< std::optional< uint32_t >, 3 > kInstrStreamVariants = {std::nullopt, 0, 1}

Protected Functions

Type Name
bool CanEnqInstrToStream (uint32_t wid, std::optional< uint32_t > ssw, uint64_t wpc) const
Check if an instruction can be enqueued to the stream.
void EnqInstrToStream (uint32_t wid, std::optional< uint32_t > ssw, InstrPtr instr)
Enqueue an instruction into the instruction stream.
void FlushFIFO (sim::SizedQueue< InstrPtr > * fifo)
Flush all instructions in FIFO.
void RedirectInstrStream (uint32_t wid, uint64_t fetch_pc, std::optional< uint32_t > ssw)
Reset next_pc and fetch_pc.
void UpdateFetchPC (InstrStream * is, std::optional< uint32_t > ssw)
Update the fetch PC of a given instruction stream.

Public Functions Documentation

function CanEnq

Check if an instruction can be enqueued. 

bool simtix::pipelined::InstrBuffer::CanEnq (
    const InstrPtr & instr
) const

Parameters:

  • instr The instruction to check.

Returns:

True if the instruction can be enqueued.

function Deq

Dequeue an instruction from a warp's instruction stream. 

InstrPtr simtix::pipelined::InstrBuffer::Deq (
    uint32_t wid,
    std::optional< uint32_t > ssw
)

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

The instruction at the front of the stream.

function Disable

Disable a warp’s instruction buffer when encountering exceptions. 

void simtix::pipelined::InstrBuffer::Disable (
    uint32_t wid
)

Parameters:

function Enable

Initialize each warp’s instruction buffer when doing PipelinedSM::Process . 

void simtix::pipelined::InstrBuffer::Enable (
    uint32_t wid,
    uint64_t next_pc
)

Parameters:

function Enq

Enqueue an instruction into the buffer. 

void simtix::pipelined::InstrBuffer::Enq (
    InstrPtr instr
)

Parameters:

  • instr The instruction to enqueue.

function ForEachValidInstrStream

Iterate over each valid instruction stream. 

template<class TFunc>
inline void simtix::pipelined::InstrBuffer::ForEachValidInstrStream (
    TFunc cb
)

Parameters:

  • cb Callback function that takes (wid, ssw).

function InstrBuffer

Construct the instruction buffer. 

explicit simtix::pipelined::InstrBuffer::InstrBuffer (
    PipelinedSMImpl * sm,
    const ArchParam & p=kDefaultArchParam,
    const PipelinedSM::Param & pp=PipelinedSM::kDefaultParam
)

Parameters:

  • sm Pointer to the owning SM implementation.
  • p Architecture parameters from param.h.
  • pp Pipeline configuration parameters from pipeline.h.

function NotifyCtrlFlowChange

Notify the buffer of a control flow change (divergence or convergence). 

void simtix::pipelined::InstrBuffer::NotifyCtrlFlowChange (
    uint32_t wid,
    uint64_t wpc,
    std::optional< uint64_t > sswpc
)

Parameters:

  • wid Warp ID.
  • wpc Redirected PC for the warp.
  • sswpc Redirected spatial sub-warp PC from the warp.

function Reset

Reset the entire instruction buffer (all warps). 

void simtix::pipelined::InstrBuffer::Reset ()

function capacious

Check if the instruction stream can accommodate more instructions. 

inline virtual bool simtix::pipelined::InstrBuffer::capacious (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

True if enough space is available.

function capacity

Get the instruction buffer capacity for a warp. 

inline std::size_t simtix::pipelined::InstrBuffer::capacity (
    uint32_t wid
) const

Parameters:

Returns:

Capacity value.

function empty

Check if the instruction stream is empty. 

inline bool simtix::pipelined::InstrBuffer::empty (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

True if empty.

function fetch_pc

Get the current fetch PC. 

inline virtual uint64_t simtix::pipelined::InstrBuffer::fetch_pc (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

Fetch PC value.

function front

Get the instruction at the front of a warp’s instruction stream. 

inline const InstrPtr & simtix::pipelined::InstrBuffer::front (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

A const reference to the front instruction.

function full

Check if the instruction stream is full. 

inline bool simtix::pipelined::InstrBuffer::full (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

True if full.

function is_diverged

Check whether the warp has diverged. 

inline bool simtix::pipelined::InstrBuffer::is_diverged (
    uint32_t wid
) const

Parameters:

Returns:

True if diverged.

function next_pc

Get the next PC for the warp’s instruction stream. 

inline uint64_t simtix::pipelined::InstrBuffer::next_pc (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

Next PC value.

function set_fetch_pc

Set the fetch PC for a given warp. 

inline void simtix::pipelined::InstrBuffer::set_fetch_pc (
    uint32_t wid,
    std::optional< uint32_t > ssw,
    uint64_t fetch_pc
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.
  • fetch_pc New fetch PC to set.

function size

Get the number of instructions currently buffered. 

inline std::size_t simtix::pipelined::InstrBuffer::size (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

Number of instructions.

function valid

Check whether the instruction stream is valid. 

inline bool simtix::pipelined::InstrBuffer::valid (
    uint32_t wid,
    std::optional< uint32_t > ssw
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.

Returns:

True if valid.

function ~InstrBuffer

virtual simtix::pipelined::InstrBuffer::~InstrBuffer () = default

Protected Attributes Documentation

variable buf_

std::vector<std::unique_ptr<InstrStream> > simtix::pipelined::InstrBuffer::buf_;

variable capacity_

std::size_t simtix::pipelined::InstrBuffer::capacity_;

variable kFetchWidth

const uint32_t simtix::pipelined::InstrBuffer::kFetchWidth;

variable sm_

PipelinedSMImpl* simtix::pipelined::InstrBuffer::sm_;

Protected Static Attributes Documentation

variable kInstrStreamVariants

constexpr std::array<std::optional<uint32_t>, 3> simtix::pipelined::InstrBuffer::kInstrStreamVariants;

Protected Functions Documentation

function CanEnqInstrToStream

Check if an instruction can be enqueued to the stream. 

inline bool simtix::pipelined::InstrBuffer::CanEnqInstrToStream (
    uint32_t wid,
    std::optional< uint32_t > ssw,
    uint64_t wpc
) const

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.
  • wpc Warp PC.

Returns:

True if the instruction can be enqueued.

function EnqInstrToStream

Enqueue an instruction into the instruction stream. 

void simtix::pipelined::InstrBuffer::EnqInstrToStream (
    uint32_t wid,
    std::optional< uint32_t > ssw,
    InstrPtr instr
)

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.
  • instr The instruction to enqueue.

function FlushFIFO

Flush all instructions in FIFO. 

inline void simtix::pipelined::InstrBuffer::FlushFIFO (
    sim::SizedQueue < InstrPtr > * fifo
)

Parameters:

  • fifo Pointer to a InstrPtr FIFO queue.

function RedirectInstrStream

Reset next_pc and fetch_pc. 

void simtix::pipelined::InstrBuffer::RedirectInstrStream (
    uint32_t wid,
    uint64_t fetch_pc,
    std::optional< uint32_t > ssw
)

Parameters:

  • wid Warp ID.
  • ssw Spatial sub-warp ID.
  • next_pc Next PC.

When the execution path of a warp changed, use this method to redirect the corresponding warp's instruction buffer.

function UpdateFetchPC

Update the fetch PC of a given instruction stream. 

inline void simtix::pipelined::InstrBuffer::UpdateFetchPC (
    InstrStream * is,
    std::optional< uint32_t > ssw
)

Parameters:

  • is Pointer to the instruction stream to update.
  • ssw Spatial sub-warp ID.

Sets fetch_pc to the maximum of the current fetch_pc and next_pc.

The documentation for this class was generated from the following file projects/simtix/src/simtix/sm/pipelined/instr_buffer.h