completionunit.cpp

ppc750 system design simulator using system c

					if(Debug(DebugCompletionUnit))
						cout << name() << ": Write Back rr" << (int) robEntry.extra.systemRegister.tags.resultTag << " to r" << dstReg << endl;
#endif
					outWriteBack[writeBackPort] = true;
					outWriteBackRegisterNumber[writeBackPort] = dstReg;
					outWriteBackRenameNumber[writeBackPort] = robEntry.extra.systemRegister.tags.resultTag;
					writeBackPort++;
				}
				
				if(robEntry.extra.systemRegister.tags.LRTag >= 0)
				{
					/* Instruction has to write into LR */
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
						cout << name() << ": Write Back LR rename buffer #" << (int) robEntry.extra.systemRegister.tags.LRTag << endl;
#endif
					outWriteBackLR[writeBackLRPort] = true;
					outWriteBackLRRenameNumber[writeBackLRPort] = robEntry.extra.systemRegister.tags.LRTag;
					writeBackLRPort++;
				}
				
				if(robEntry.extra.systemRegister.tags.CTRTag >= 0)
				{
					/* Instruction has to write into CTR */
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
						cout << name() << ": Write Back CTR rename buffer #" << (int) robEntry.extra.systemRegister.tags.CTRTag << endl;
#endif
					outWriteBackCTR[writeBackCTRPort] = true;
					outWriteBackCTRRenameNumber[writeBackCTRPort] = robEntry.extra.systemRegister.tags.CTRTag;
					writeBackCTRPort++;
				}
				
				if(robEntry.extra.systemRegister.tags.CRTag >= 0)
				{
					/* Instruction has to write a CR field */
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
						cout << name() << ": Write Back CR rename buffer #" << (int) robEntry.extra.systemRegister.tags.CRTag << endl;
#endif
					outWriteBackCR[writeBackCRPort] = true;
					outWriteBackCRRenameNumber[writeBackCRPort] = robEntry.extra.systemRegister.tags.CRTag;
					outWriteBackCRFieldNumber[writeBackCRPort] = registersBinding->GetField(robEntry.extra.systemRegister.tags.CRTag);
					writeBackCRPort++;
				}
				
				if(robEntry.extra.systemRegister.writeCR)
				{
					/* Instruction has to write into CR (with a binary mask) */
					writeCR = true;
					outCRM = robEntry.extra.systemRegister.crm;
					outCR = robEntry.extra.systemRegister.cr;
				}
				break;
		}
	}
	
	outWriteCR = writeCR;
	
#ifdef DEBUG
	if(Debug(DebugCompletionUnit))
		cout << name() << ": " << writeBackPort << " registers written back" << endl;
#endif
	
	/* Don't write on unused write back ports */
	for(; writeBackPort < nWriteBackPorts; writeBackPort++)
		outWriteBack[writeBackPort] = false;
	
	for(; writeBackFloatingPointPort < nWriteBackFloatingPointPorts; writeBackFloatingPointPort++)
		outWriteBackFloatingPoint[writeBackFloatingPointPort] = false;
	
	for(; writeBackCRPort < nWriteBackCRPorts; writeBackCRPort++)
		outWriteBackCR[writeBackCRPort] = false;
		
	for(; writeBackLRPort < nWriteBackLRPorts; writeBackLRPort++)
		outWriteBackLR[writeBackLRPort] = false;
		
	for(; writeBackCTRPort < nWriteBackCTRPorts; writeBackCTRPort++)
		outWriteBackCTR[writeBackCTRPort] = false;
		
	for(; memoryWriteBackPort < nMemoryWriteBackPorts; memoryWriteBackPort++)
		outMemoryWriteBack[memoryWriteBackPort] = false;
		
	outWriteCarry = writeCarry;
	outWriteOverflow = writeOverflow;

	nInstructionsToRetire = nInstructionsToWriteBack;		
	
	/* Retire */

#ifdef DEBUG
	if(Debug(DebugCompletionUnit))
		if(nInstructionsToRetire > 0)
			cout << name() << ": Retiring " << nInstructionsToRetire << " instructions" << endl;
		
#endif
	nRetiredInstructions += nInstructionsToRetire;
	
	bool clearInterlock = false;
		
	for(i = 0; i < nInstructionsToRetire; i++)
	{
		/* Get a reorder buffer entry (from the oldest to the newest) */
		ReorderBufferEntry& robEntry = rob->GetTail();
		
		programCounter = robEntry.nia;
		
		switch(robEntry.unitIdent)
		{
			case IntegerUnitIdent:
#ifdef DEBUG
				if(Debug(DebugCompletionUnit))
				{
					cout << name() << ": Retiring instruction (tag = " << (int) robEntry.extra.integer.tags.tag << ")  (" << robEntry.dbgInstructionCounter << ")  ";
					ppc_disassemble_to_stream(robEntry.dbgInstruction, robEntry.dbgProgramCounter, stdout);
					cout << endl;
				}
#endif
#ifdef TRACE
				if(Trace(TraceCompletionUnit))
				{
					trace_file->Begin("retire");
					trace_file->Value("number", robEntry.dbgInstructionCounter);
					trace_file->Value("pc", robEntry.dbgProgramCounter);
					trace_file->End("retire");
				}
#endif
#ifdef EMULATE
				/* Emulator code begins */
				ppc_execute_check_path(robEntry.inst, robEntry.instPC);
				/* Emulator code ends */
#endif

				/* Free the rename buffers */
				if(robEntry.extra.integer.tags.resultTag >= 0)
					registersBinding->FreeRenameBuffer(robEntry.extra.integer.tags.resultTag);
					
				if(robEntry.extra.integer.tags.CRTag >= 0)
					registersBinding->FreeCRRenameBuffer(robEntry.extra.integer.tags.CRTag);
					
				break;
					
			case FloatingPointUnitIdent:
#ifdef DEBUG
				if(Debug(DebugCompletionUnit))
				{
					cout << name() << ": Retiring instruction (tag = " << (int) robEntry.extra.floatingPoint.tags.tag << ")  (" << robEntry.dbgInstructionCounter << ")  ";
					ppc_disassemble_to_stream(robEntry.dbgInstruction, robEntry.dbgProgramCounter, stdout);
					cout << endl;
				}
#endif
#ifdef EMULATE
				/* Emulator code begins */
				ppc_execute_check_path(robEntry.inst, robEntry.instPC);
				/* Emulator code ends */
#endif

				/* Free the rename buffers */
				if(robEntry.extra.floatingPoint.tags.resultTag >= 0)
					registersBinding->FreeFloatingPointRenameBuffer(robEntry.extra.floatingPoint.tags.resultTag);
					
				if(robEntry.extra.floatingPoint.tags.CRTag >= 0)
					registersBinding->FreeCRRenameBuffer(robEntry.extra.floatingPoint.tags.CRTag);
					
				break;
				
			case LoadStoreUnitIdent:
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
					{
						cout << name() << ": Retiring instruction (tag = " << (int) robEntry.extra.loadStore.tags.tag << ")  (" << robEntry.dbgInstructionCounter << ")  ";
						ppc_disassemble_to_stream(robEntry.dbgInstruction, robEntry.dbgProgramCounter, stdout);
						cout << endl;
					}
#endif
#ifdef EMULATE
					/* Emulator code begins */
					ppc_execute_check_path(robEntry.inst, robEntry.instPC);
					/* Emulator code ends */
#endif
					/* Free the rename buffers */
					if(robEntry.extra.loadStore.tags.resultTags[0] >= 0)
					{
						if(robEntry.extra.loadStore.floatingPoint)
						{
							registersBinding->FreeFloatingPointRenameBuffer(robEntry.extra.loadStore.tags.resultTags[0]);
						}
						else
						{
							registersBinding->FreeRenameBuffer(robEntry.extra.loadStore.tags.resultTags[0]);
						}
					}
					
					if(robEntry.extra.loadStore.tags.resultTags[1] >= 0)
						registersBinding->FreeRenameBuffer(robEntry.extra.loadStore.tags.resultTags[1]);
							
					break;
					
				case BranchUnitIdent:
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
					{
						cout << name() << ": Retiring instruction (tag = " << (int) robEntry.extra.branch.tags.tag << ")  (" << robEntry.dbgInstructionCounter << ")  ";
						ppc_disassemble_to_stream(robEntry.dbgInstruction, robEntry.dbgProgramCounter, stdout);
						cout << endl;
					}
#endif
#ifdef EMULATE
					/* Emulator code begins */
					ppc_execute_check_path(robEntry.inst, robEntry.instPC);
					/* Emulator code ends */
#endif
					/* Free the rename buffers */
					if(robEntry.extra.branch.tags.LRTag >= 0)
						registersBinding->FreeLRRenameBuffer(robEntry.extra.branch.tags.LRTag);
						
					if(robEntry.extra.branch.tags.CTRTag >= 0)
						registersBinding->FreeCTRRenameBuffer(robEntry.extra.branch.tags.CTRTag);

																		
					break;
					
				case SystemRegisterUnitIdent:
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
					{
						cout << name() << ": Retiring instruction (tag = " << (int) robEntry.extra.systemRegister.tags.tag << ")  (" << robEntry.dbgInstructionCounter << ")  ";
						ppc_disassemble_to_stream(robEntry.dbgInstruction, robEntry.dbgProgramCounter, stdout);
						cout << endl;
					}
#endif
#ifdef EMULATE
					/* Emulator code begins */
					ppc_execute_check_path(robEntry.inst, robEntry.instPC);
					/* Emulator code ends */
#endif
					
					/* Free the rename buffers */
					if(robEntry.extra.systemRegister.tags.resultTag >= 0)
						registersBinding->FreeRenameBuffer(robEntry.extra.systemRegister.tags.resultTag);
						
					if(robEntry.extra.systemRegister.tags.LRTag >= 0)
						registersBinding->FreeLRRenameBuffer(robEntry.extra.systemRegister.tags.LRTag);
						
					if(robEntry.extra.systemRegister.tags.CTRTag >= 0)
						registersBinding->FreeCTRRenameBuffer(robEntry.extra.systemRegister.tags.CTRTag);
					
					if(robEntry.extra.systemRegister.tags.CRTag >= 0)
						registersBinding->FreeCRRenameBuffer(robEntry.extra.systemRegister.tags.CRTag);
						
					if(robEntry.extra.systemRegister.interlock)
					{
						/* Clear the interlock bit */
						clearInterlock = true;
					}
					break;
		}
		rob->ReleaseTail();
	}
	
	outClearInterlock = clearInterlock;
	
	bool integerExecute[nIntegerUnit];
	bool floatingPointExecute[nFloatingPointUnits];
	bool systemRegisterExecute = false;

	/* Allow an execution serialized instruction to execute if it is the oldest instruction */
	for(i = 0; i < nIntegerUnit; i++)
		integerExecute[i] = false;
	
	for(i = 0; i < nFloatingPointUnits; i++)
		floatingPointExecute[i] = false;
	
	if(!rob->Empty())
	{
	
		ReorderBufferEntry& robEntry = rob->GetTail();
		if(!robEntry.finished && robEntry.executionSerialized)
		{
			/* Instruction that is execution serialized is the oldest instruction into the reorder buffer */
			switch(robEntry.unitIdent)
			{
				case IntegerUnitIdent:
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
						cout << name() << ": integer execution serialized instruction is ready to be executed (tag =" << (int) rob->GetIndex(robEntry) << ")" << endl;
#endif
					integerExecute[robEntry.extra.integer.unitNumber] = true;
					outIntegerExecuteTag[robEntry.extra.integer.unitNumber] = robEntry.extra.integer.tags.tag;
					break;
					
				case FloatingPointUnitIdent:
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
						cout << name() << ": floating point execution serialized instruction is ready to be executed (tag =" << (int) rob->GetIndex(robEntry) << ")" << endl;
#endif
					floatingPointExecute[robEntry.extra.floatingPoint.unitNumber] = true;
					outFloatingPointExecuteTag[robEntry.extra.floatingPoint.unitNumber] = robEntry.extra.floatingPoint.tags.tag;
					break;				
					
				case SystemRegisterUnitIdent:
#ifdef DEBUG
					if(Debug(DebugCompletionUnit))
						cout << name() << ": system register execution serialized instruction is ready to be executed (tag =" << (int) rob->GetIndex(robEntry) << ")" << endl;
#endif
					systemRegisterExecute = true;
					outSystemRegisterExecuteTag = robEntry.extra.systemRegister.tags.tag;					
					break;
			}
		}
	}
	
	for(i = 0; i < nIntegerUnit; i++)
		outIntegerExecute[i] = integerExecute[i];
		
	for(i = 0; i < nFloatingPointUnits; i++)
		outFloatingPointExecute[i] = floatingPointExecute[i];
		
	outSystemRegisterExecute = systemRegisterExecute;
	
	/* Wake up decode process of the dispatch unit */
	outDecode = rob->GetFreeSpace() > 0;	
}

void CompletionUnit::Finish()
{
	int i;
	
	/* Validate the rename buffers */

	for(i = 0; i < nIntegerUnit; i++)
	{
		if(inIntegerResultValid[i])
		{
			/* An integer unit produced a rename buffer */
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
				cout << name() << ": integer unit " << i << " produce rename buffer #" << (int) inIntegerResultTag[i] << endl;
#endif
			/* Validate the rename buffer  */
			registersBinding->ValidateRenameBuffer(inIntegerResultTag[i]);
		}
		
		if(inIntegerResultCRValid[i])
		{
			/* An integer unit produced a CR field rename buffer */
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
				cout << name() << ": integer unit " << i << " produce cr rename buffer #" << (int) inIntegerResultCRTag[i] << endl;
#endif
			/* Validate the CR field rename buffer */
			registersBinding->ValidateCRRenameBuffer(inIntegerResultCRTag[i]);
		}
	}
	
	for(i = 0; i < nFloatingPointUnits; i++)
	{
		if(inFloatingPointResultValid[i])
		{
			/* A floating point unit produced a floating point rename buffer */
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
				cout << name() << ": floating point unit " << i << " produce floating point rename buffer #" << (int) inFloatingPointResultTag[i] << endl;
#endif
			/* Validate the floating point rename buffer */
			registersBinding->ValidateFloatingPointRenameBuffer(inFloatingPointResultTag[i]);
		}
		
		if(inFloatingPointResultCRValid[i])
		{
			/* A floating point unit produced a CR field rename buffer */
#ifdef DEBUG
			if(Debug(DebugCompletionUnit))
				cout << name() << ": floating point unit " << i << " produce cr rename buffer #" << (int) inFloatingPointResultCRTag[i] << endl;
#endif
			/* Validate the CR field rename buffer */
			registersBinding->ValidateCRRenameBuffer(inFloatingPointResultCRTag[i]);
		}
	}
	
	if(inLoadStoreFloatingPointResultValid)