#include <TransportPipeline.hh>

Inheritance diagram for TransportPipeline:

Collaboration diagram for TransportPipeline:

Public Member Functions
	TransportPipeline (GCUState &parent)

virtual	~TransportPipeline ()

virtual int	latency () const

virtual void	startOperation (Operation &op)

virtual void	advanceClock ()

virtual OperationExecutor *	copy ()

virtual void	setContext (OperationContext &context)

bool	hasPendingOperations () const

Public Member Functions inherited from OperationExecutor
	OperationExecutor ()

	OperationExecutor (FUState &parent)

virtual	~OperationExecutor ()

FUState &	parent () const

void	setParent (FUState &parent)

void	addBinding (int io, PortState &port)

PortState &	binding (int io) const

bool	hasPendingOperations () const

virtual void	reset ()

Private Member Functions
TransportPipeline &	operator= (const TransportPipeline &)
	Assignment not allowed.

Private Attributes
Operation *	operation_
	Operation to be triggered next.

OperationContext *	context_
	Operation context used to fetch the values for PC and RA.

OperationContext	tempContext_
	Operation context seen by the operation.

InstructionAddress	PC_
	Storage for PC value in the context.

InstructionAddress	IBS_
	Storage for IRF block start in the context.

SimValue	RA_
	Storage for RA value in the context.

int	branchDelayCycles_
	Branch delay cycles.

GCUState &	parent_
	The owner GCUState.

Additional Inherited Members
Protected Attributes inherited from OperationExecutor
std::vector< PortState * >	bindings_
	PortStates that are bound to a certain input or output operand.

bool	hasPendingOperations_
	This is set to true if the OperationExecutor is not in 'idle' mode.

Detailed Description

Models the transport pipeline of global control unit.

Definition at line 49 of file TransportPipeline.hh.

Constructor & Destructor Documentation

◆ TransportPipeline()

TransportPipeline::TransportPipeline ( GCUState & parent )

explicit

Constructor.

Parameters

parent Parent of the pipeline.

Definition at line 57 of file TransportPipeline.cc.

                                                     : 
    OperationExecutor(parent), operation_(NULL), 
    context_(&parent.context()), 
    tempContext_(NULL, PC_, RA_, parent.context().branchDelayCycles()),
    parent_(parent) {
    // delete the own state registry to avoid mem leaks
    delete &tempContext_.stateRegistry();
    // share the state registry with the actual context
    tempContext_.setStateRegistry(parent.context().stateRegistry());
}

References FUState::context(), OperationExecutor::parent(), OperationContext::setStateRegistry(), OperationContext::stateRegistry(), and tempContext_.

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◆ ~TransportPipeline()

TransportPipeline::~TransportPipeline ( )

virtual

Destructor.

Definition at line 71 of file TransportPipeline.cc.

                                      {
    tempContext_.unsetStateRegistry();
}

References tempContext_, and OperationContext::unsetStateRegistry().

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Member Function Documentation

◆ advanceClock()

void TransportPipeline::advanceClock ( )

virtual

Nothing is done when clock cycle changes.

Implements OperationExecutor.

Definition at line 130 of file TransportPipeline.cc.

130 {

131}

◆ copy()

OperationExecutor * TransportPipeline::copy ( )

virtual

Copies OperationExecutor.

Returns: The copied OperationExecutor.

Implements OperationExecutor.

Definition at line 139 of file TransportPipeline.cc.

                        {
    return new TransportPipeline(*this);
}

◆ hasPendingOperations()

bool TransportPipeline::hasPendingOperations ( ) const

inline

Definition at line 59 of file TransportPipeline.hh.

                                      {
        return true;
    }

◆ latency()

int TransportPipeline::latency ( ) const

virtual

Returns the latency of the pipeline.

Returns: The latency of the pipeline.

Definition at line 81 of file TransportPipeline.cc.

                                 {
    return 0;
}

◆ operator=()

TransportPipeline & TransportPipeline::operator= ( const TransportPipeline & )

private

Assignment not allowed.

◆ setContext()

void TransportPipeline::setContext ( OperationContext & context )

virtual

Sets the OperationContext of the pipeline.

Parameters

context The OperationContext.

Implements OperationExecutor.

Definition at line 149 of file TransportPipeline.cc.

                                                       {
    context_ = &context;
}

References context_.

◆ startOperation()

void TransportPipeline::startOperation ( Operation & op )

virtual

Start the execution of the operation.

First inputs and outputs of the operation are collected in a vector. Then a new operation context is created. After triggering the operation the registers which values are changed are updated in parent GCU state.

Parameters

op	Operation to be triggered.

Todo:: This can be optimized a lot.

Implements OperationExecutor.

Definition at line 96 of file TransportPipeline.cc.

                                               {
 
    operation_ = &op;
    int operands = op.numberOfInputs() + op.numberOfOutputs();
    SimValue* io[32];
    assert(operands < 32);
    for (int i = 0; i < operands; ++i)
        io[i] = const_cast<SimValue*>(&(binding(i + 1).value()));
 
    // use a temporary context here as the original context points to the
    // internal program counter variables of the simulator engine,
    // which we do not want to modify in the middle of simulating 
    // a cycle
    tempContext_.programCounter() = context_->programCounter();
    tempContext_.returnAddress() = context_->returnAddress();
    tempContext_.setSaveReturnAddress(false);
    tempContext_.setUpdateProgramCounter(false);
    operation_->simulateTrigger(io, tempContext_);
 
    // If the operation is a jump or a call operation, update the program
    // counter after delay slot cycles. If a loop buffer setup op is called,
    // do not update the program counter this way.
    if (tempContext_.updateProgramCounter() && (op.isCall() || op.isBranch())) {
        parent_.setProgramCounter(tempContext_.programCounter());
    }
    if (tempContext_.saveReturnAddress()) {
        parent_.setReturnAddress();        
    }
}

References assert, OperationExecutor::binding(), context_, Operation::isBranch(), Operation::isCall(), Operation::numberOfInputs(), Operation::numberOfOutputs(), operation_, parent_, OperationContext::programCounter(), OperationContext::returnAddress(), OperationContext::saveReturnAddress(), GCUState::setProgramCounter(), GCUState::setReturnAddress(), OperationContext::setSaveReturnAddress(), OperationContext::setUpdateProgramCounter(), Operation::simulateTrigger(), tempContext_, and OperationContext::updateProgramCounter().

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Member Data Documentation

◆ branchDelayCycles_

int TransportPipeline::branchDelayCycles_

private

Branch delay cycles.

Definition at line 80 of file TransportPipeline.hh.

◆ context_

OperationContext* TransportPipeline::context_

private

Operation context used to fetch the values for PC and RA.

Definition at line 70 of file TransportPipeline.hh.

Referenced by setContext(), and startOperation().

◆ IBS_

InstructionAddress TransportPipeline::IBS_

private

Storage for IRF block start in the context.

Definition at line 76 of file TransportPipeline.hh.

◆ operation_

Operation* TransportPipeline::operation_

private

Operation to be triggered next.

Definition at line 68 of file TransportPipeline.hh.

Referenced by startOperation().

◆ parent_

GCUState& TransportPipeline::parent_

private

The owner GCUState.

Definition at line 82 of file TransportPipeline.hh.

Referenced by startOperation().

◆ PC_

InstructionAddress TransportPipeline::PC_

private

Storage for PC value in the context.

Definition at line 74 of file TransportPipeline.hh.

◆ RA_

SimValue TransportPipeline::RA_

private

Storage for RA value in the context.

Definition at line 78 of file TransportPipeline.hh.

◆ tempContext_

OperationContext TransportPipeline::tempContext_

private

Operation context seen by the operation.

Definition at line 72 of file TransportPipeline.hh.

Referenced by startOperation(), TransportPipeline(), and ~TransportPipeline().

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

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ TransportPipeline()

◆ ~TransportPipeline()

Member Function Documentation

◆ advanceClock()

◆ copy()

◆ hasPendingOperations()

◆ latency()

◆ operator=()

◆ setContext()

◆ startOperation()

Member Data Documentation

◆ branchDelayCycles_

◆ context_

◆ IBS_

◆ operation_

◆ parent_

◆ PC_

◆ RA_

◆ tempContext_