completionunit.cpp

ppc750 system design simulator using system c

	{
		/* Load/store unit produced a floating point rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": load/Store unit produce floating point rename buffer #" << (int) inLoadStoreResultTag[0] << endl;
#endif
		/* Validate the floating point rename buffer */
		registersBinding->ValidateFloatingPointRenameBuffer(inLoadStoreResultTag[0]);
	}
	else if(inLoadStoreResultValid[0])
	{
		/* Load/store unit produced a rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": load/Store unit produce rename buffer #" << (int) inLoadStoreResultTag[0] << endl;
#endif
		/* validate the rename buffer */
		registersBinding->ValidateRenameBuffer(inLoadStoreResultTag[0]);
	}
		
	if(inLoadStoreResultValid[1])
	{
		/* Load/store unit produced a rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": load/Store unit produce rename buffer #" << (int) inLoadStoreResultTag[1] << endl;
#endif
		/* validate the rename buffer */
		registersBinding->ValidateRenameBuffer(inLoadStoreResultTag[1]);
	}
	
	if(inBranchResultLRValid)
	{
		/* Branch unit produced a LR rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": branch unit produce rename LR buffer #" << (int) inBranchResultLRTag << endl;
#endif
		/* Validate the LR rename buffer */
		registersBinding->ValidateLRRenameBuffer(inBranchResultLRTag);
	}
		
	if(inBranchResultCTRValid)
	{
		/* branch unit produced a CTR rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": branch unit produce rename buffer #" << (int) inBranchResultCTRTag << endl;
#endif
		/* valid the CTR rename buffer */
		registersBinding->ValidateCTRRenameBuffer(inBranchResultCTRTag);
	}
	
	if(inSystemRegisterResultValid)
	{
		/* System Register Unit produced a rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": system register unit produce rename buffer #" << (int) inSystemRegisterResultTag << endl;
#endif
		/* Validate the rename buffer */
		registersBinding->ValidateRenameBuffer(inSystemRegisterResultTag);
	}
		
	if(inSystemRegisterResultLRValid)
	{
		/* System Register Unit produced a LR rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": system register unit produce LR rename buffer #" << (int) inSystemRegisterResultLRTag << endl;
#endif
		/* Validate the LR rename buffer */
		registersBinding->ValidateLRRenameBuffer(inSystemRegisterResultLRTag);
	}
	
	if(inSystemRegisterResultCTRValid)
	{
		/* System register Unit produced a CTR rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": system register unit produce CTR rename buffer #" << (int) inSystemRegisterResultCTRTag << endl;
#endif
		/* Validate the CTR rename buffer */
		registersBinding->ValidateCTRRenameBuffer(inSystemRegisterResultCTRTag);
	}
	
	if(inSystemRegisterResultCRValid)
	{
		/* System Register Unit produced a CR field rename buffer */
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
			cout << name() << ": system register unit produce CR rename buffer #" << (int) inSystemRegisterResultCRTag << endl;
#endif
		/* Validate the CR field rename buffer */
		registersBinding->ValidateCRRenameBuffer(inSystemRegisterResultCRTag);
	}
	
	/* Finish */
	
	for(i = 0; i < nIntegerUnit; i++)
	{
		if(inIntegerFinished[i])
		{
			/* An integer unit finished an instruction */
			tag_t tag = inIntegerTag[i];
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
			{
				cout << name() << ": integer unit " << i << " has finished an instruction (tag = " << (int) tag << ")" << endl;
				if(!rob->Contains(tag))
				{
					cout << name() << ": Error : Reorder buffer does not contain tag " << (int) tag << endl;
					ABORT();
				}
			}
#endif
			/* Get the reorder buffer entry containing that instruction */
			ReorderBufferEntry& robEntry = rob->GetEntry(tag);
			/* Finish the instruction */
			robEntry.finished = true;
			/* Collect result that must be temporaly stored into the reorder buffer (XER[OV] and XER[CA])*/
			if(robEntry.extra.integer.writeOverflow) robEntry.extra.integer.overflow = inIntegerOverflow[i];
			if(robEntry.extra.integer.writeCarry) robEntry.extra.integer.carry = inIntegerCarry[i];
			if(robEntry.executionSerialized) outIntegerExecute[i] = false;
#ifdef TRACE
			if(Trace(TraceCompletionUnit))
			{
				trace_file->Begin("finish");
				trace_file->Value("number", robEntry.dbgInstructionCounter);
				trace_file->Value("pc", robEntry.dbgProgramCounter);
				trace_file->End("finish");
			}
#endif
		}
	}
	
	for(i = 0; i < nFloatingPointUnits; i++)
	{
		if(inFloatingPointFinished[i])
		{
			/* A Floating point unit finished an instruction */
			tag_t tag = inFloatingPointTag[i];
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
			{
				cout << name() << ": floating point unit " << i << " has finished an instruction (tag = " << (int) tag << ")" << endl;
				if(!rob->Contains(tag))
				{
					cout << name() << ": Error : Reorder buffer does not contain tag " << (int) tag << endl;
					ABORT();
				}
			}
#endif
			/* Get the reorder buffer entry containing that instruction */
			ReorderBufferEntry& robEntry = rob->GetEntry(tag);
			/* Finish the instruction */
			robEntry.finished = true;
			if(robEntry.executionSerialized) outFloatingPointExecute[i] = false;
		}
	}
	
	for(i = 0; i < 2; i++)
	{
		if(inLoadStoreFinished[i])
		{
			/* Load/store unit finished an instruction */
			tag_t tag = inLoadStoreTag[i];
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
			{
				cout << name() << ": load/store unit has finished an instruction (tag = " << (int) tag  << ")" << endl;
				if(!rob->Contains(tag))
				{
					cout << name() << ": Reorder buffer does not contain this instruction (tag = " << (int) tag << ")" << endl;
					ABORT();
				}
			}
#endif
			/* Get the reorder buffer entry containing that instruction */
			ReorderBufferEntry& robEntry = rob->GetEntry(tag);
			/* Finish the instruction */
			robEntry.finished = true;
		}
	}
	
	if(inSystemRegisterFinished)
	{
		/* System Register Unit finished an instruction */
		tag_t tag = inSystemRegisterTag;
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
		{
			cout << name() << ": system register unit has finished an instruction (tag = " << (int) tag << ")" << endl;
			if(!rob->Contains(tag))
			{
				cout << name() << ": Reorder buffer does not contain this instruction (tag = " << (int) tag << ")" << endl;
				ABORT();
			}
		}
#endif
		/* Get the reorder buffer entry containing that instruction */
		ReorderBufferEntry& robEntry = rob->GetEntry(tag);
		/* Finish the instruction */
		robEntry.finished = true;
		if(robEntry.extra.systemRegister.writeCR) robEntry.extra.systemRegister.cr = inSystemRegisterCRData;
	}
	
	if(inBranchFinished)
	{
		/* Branch unit finished an instruction */
		if(inBranchTag != -1)
		{
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
			{
				cout << name() << ": branch unit has finished an instruction (tag = " << (int) inBranchTag << ")" << endl;
				if(!rob->Contains(inBranchTag))
				{
					cout << name() << ": Reorder buffer does not contain this instruction (tag = " << (int) inBranchTag << ")" << endl;
					ABORT();
				}
			}
#endif
			/* Get the reorder buffer entry containing that instruction */
			ReorderBufferEntry& robEntry = rob->GetEntry(inBranchTag);
			/* Finish the instruction */
			robEntry.finished = true;		
		}
		else
		{
			nRetiredInstructions++;
		}
		
		if(inMispredictedBranch)
		{
			/* If branch has been mispredicted then flush dependent instructions */
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
			{
				cout << name() << ": Mispredicted Branch" << endl;
				cout << name() << ": Reorder buffer content before flushing :" << endl << *rob;
				cout << name() << ": Registers Binding before flushing :" << endl << *registersBinding;
			}
#endif
			Flush();
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
			{
				cout << name() << ": Reorder buffer content after flushing :" << endl << *rob;
				cout << name() << ": Registers Binding after flushing :" << endl << *registersBinding;
			}
#endif
		}
		else
		{
			/* The branch has been resolved and branch preduction was good */
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
				cout << name() << ": Decrement Branch Counter" << endl;
#endif
			rob->DecrementBranchCounter();
		}
	}
	
#ifdef DEBUG
	if(Debug(DebugCompletionUnit))
	{
		cout << "Reorder buffer content :" << endl;
		cout << *rob;
	}
#endif
}

void CompletionUnit::OnFallingEdge()
{
	if(nMaxRetiredInstructions > 0 && nRetiredInstructions >= nMaxRetiredInstructions)
	{
		StopSimulation();
	}
}

void CompletionUnit::Flush()
{
	int j;
	
	/* Flush instructions that have their branch counter > 0 */
	/* Instructions that are flushed release some rename buffers (in reverse order they are allocated) */
	while(!rob->Empty())
	{
		ReorderBufferEntry& robEntry = rob->GetHead();
		
		if(robEntry.branchCounter == 0) return;
		
#ifdef DEBUG
		if(Debug(DebugCompletionUnit))
		{
			cout << name() << ": Flushing instruction (" << robEntry.dbgInstructionCounter << ")  ";
			ppc_disassemble_to_stream(robEntry.dbgInstruction, robEntry.dbgProgramCounter, stdout);
			cout << endl;
		}
#endif
		switch(robEntry.unitIdent)
		{
			case IntegerUnitIdent:
				if(robEntry.extra.integer.tags.resultTag >= 0)
					registersBinding->FreeRenameBufferReverseOrder(robEntry.extra.integer.tags.resultTag);
					
				if(robEntry.extra.integer.tags.CRTag >= 0)
					registersBinding->FreeCRRenameBufferReverseOrder(robEntry.extra.integer.tags.CRTag);
					
				break;
				
			case FloatingPointUnitIdent:
				if(robEntry.extra.floatingPoint.tags.resultTag >= 0)
					registersBinding->FreeFloatingPointRenameBufferReverseOrder(robEntry.extra.floatingPoint.tags.resultTag);
					
				if(robEntry.extra.floatingPoint.tags.CRTag >= 0)
					registersBinding->FreeCRRenameBufferReverseOrder(robEntry.extra.floatingPoint.tags.CRTag);
					
				break;
			
			case LoadStoreUnitIdent:
				if(robEntry.extra.loadStore.tags.resultTags[0] >= 0)
				{
					if(robEntry.extra.loadStore.floatingPoint)
					{
						registersBinding->FreeFloatingPointRenameBufferReverseOrder(robEntry.extra.loadStore.tags.resultTags[0]);
					}
					else
					{
						registersBinding->FreeRenameBufferReverseOrder(robEntry.extra.loadStore.tags.resultTags[0]);
					}
				}

				if(robEntry.extra.loadStore.tags.resultTags[1] >= 0)
						registersBinding->FreeRenameBufferReverseOrder(robEntry.extra.loadStore.tags.resultTags[1]);
				break;
				
			case BranchUnitIdent:
				if(robEntry.extra.branch.tags.LRTag >= 0)
					registersBinding->FreeLRRenameBufferReverseOrder(robEntry.extra.branch.tags.LRTag);
					
				if(robEntry.extra.branch.tags.CTRTag >= 0)
					registersBinding->FreeCTRRenameBufferReverseOrder(robEntry.extra.branch.tags.CTRTag);
					
				break;
				
			case SystemRegisterUnitIdent:
				if(robEntry.extra.systemRegister.tags.resultTag >= 0)
					registersBinding->FreeRenameBufferReverseOrder(robEntry.extra.systemRegister.tags.resultTag);
						
				if(robEntry.extra.systemRegister.tags.LRTag >= 0)
					registersBinding->FreeLRRenameBufferReverseOrder(robEntry.extra.systemRegister.tags.LRTag);
						
				if(robEntry.extra.systemRegister.tags.CTRTag >= 0)
					registersBinding->FreeCTRRenameBufferReverseOrder(robEntry.extra.systemRegister.tags.CTRTag);
					
				if(robEntry.extra.systemRegister.tags.CRTag >= 0)
					registersBinding->FreeCRRenameBufferReverseOrder(robEntry.extra.systemRegister.tags.CRTag);
					
				break;
		}
		
		rob->ReleaseHead();
	}
}

void CompletionUnit::Reset()
{
	nInstructionsToRetire = 0;
	nRetiredInstructions = 0;
	nMaxRetiredInstructions = 0;
	rob->Flush();
}

void CompletionUnit::Stop(int ninstructions)
{
	nRetiredInstructions = 0;
	nMaxRetiredInstructions = ninstructions;
}