dispatchunit.cpp

ppc750 system design simulator using system c

									cout << "source register : fp" << (int) srcReg << endl;
#endif
								tag_t tag = registersBinding->GetFloatingPointRenameBuffer(srcReg);	/* Get the floating point rename buffer */
								rs[i].loadStore->operand0.tag = tag;			/* and store its tag into the reservation station */
								rs[i].loadStore->operand0.valid = false;		/* make the reservation to wait for the rename buffer value */
							
								if(tag < 0)
								{
									 /* The source register is not renamed */
#ifdef DEBUG	
									if(Debug(DebugDispatchUnit))
									{
										cout << name() << ": Reading fp" << (int) srcReg << " value from register file" << endl;
										if(readFloatingPointRegisterPort >= nReadFloatingPointRegisterPorts)
										{
											cout << name() << ": not enough read floating point register ports" << endl;
											ABORT();
										}
									}
#endif
									loadStoreReadingFloatingPointRegister[i] = srcReg;	/* Remember that we are reading the source floating point register */
									loadStoreReadingFloatingPointRenameBuffer[i] = -1;	/* No floating point rename buffer is being read */
									loadStoreReadingRegisters[i][0] = -1;				/* No general purpose register is being read */
									loadStoreReadingRenameBuffers[i][0] = -1;			/* No rename buffer is being read */
									outReadFloatingPointRegisterNumber[readFloatingPointRegisterPort++] = srcReg;	/* Ask to the register file the value of the floating point source register hold by the floating point rename buffer */
								}
								else
								{
									/* The source register is renamed */
								
									if(registersBinding->FloatingPointRenameBufferValid(tag))
									{
										/* The floating point rename buffer yet contains the right value */
#ifdef DEBUG
										if(Debug(DebugDispatchUnit))
										{
											cout << name() << ": Reading fp" << (int) srcReg << " value from rfp" << (int) tag << endl;
											if(readFloatingPointRenamePort >= nReadFloatingPointRenamePorts)
											{
												cout << name() << ": not enough read floating point rename buffer ports" << endl;
												ABORT();
											}
										}
#endif
										loadStoreReadingFloatingPointRegister[i] = -1;		/* No floating point register is being read */
										loadStoreReadingFloatingPointRenameBuffer[i] = tag;	/* Remember that we are reading the floating point rename buffer */
										loadStoreReadingRegisters[i][0] = -1;    			/* No general purpose register is being read */
										loadStoreReadingRenameBuffers[i][0] = -1;  			/* No rename buffer is being read */
										outReadFloatingPointRenameNumber[readFloatingPointRenamePort++] = tag;	/* Ask to the register file the value of the floating point rename buffer that holds the source operand value */
									}
									else
									{
#ifdef DEBUG
										if(Debug(DebugDispatchUnit))
											cout << name() << ": Waiting for fp" << (int) srcReg << " value hold by rfp" << (int) tag << endl;
#endif		
										loadStoreReadingFloatingPointRegister[i] = -1;
										loadStoreReadingFloatingPointRenameBuffer[i] = -1;
										loadStoreReadingRegisters[i][0] = -1;
										loadStoreReadingRenameBuffers[i][0] = -1;
										/* Nothing to read from register file, just wait */
									}
								}
							}
							else
							{
								/* No source register */
								loadStoreReadingFloatingPointRegister[i] = -1;
								loadStoreReadingFloatingPointRenameBuffer[i] = -1;
								loadStoreReadingRegisters[i][0] = -1;
								loadStoreReadingRenameBuffers[i][0] = -1;
								rs[i].loadStore->operand0.tag = -1;
							}
						}
						else
						{
							loadStoreReadingFloatingPointRegister[i] = -1;
							loadStoreReadingFloatingPointRenameBuffer[i] = -1;
						
							srcReg = decodedInstructions[i].io.loadStore.srcReg[0];
						
							if(srcReg >= 0)
							{
								/* First operand is a general purpose register */
#ifdef DEBUG
								if(Debug(DebugDispatchUnit))
									cout << "source register : r" << (int) srcReg << endl;
#endif
								tag_t tag = registersBinding->GetRenameBuffer(srcReg);	/* Get the rename buffer */
								rs[i].loadStore->operand0.tag = tag;		/* and store its tag into the reservation station */
								rs[i].loadStore->operand0.valid = false;	/* make the reservation to wait for the rename buffer */
								
								if(tag < 0)
								{
									 /* The source register is not renamed */
#ifdef DEBUG	
									if(Debug(DebugDispatchUnit))
									{
										cout << name() << ": Reading r" << (int) srcReg << " value from register file" << endl;
										if(readRegisterPort >= nReadRegisterPorts)
										{
											cout << name() << ": not enough read register ports" << endl;
											ABORT();
										}
									}
#endif
									loadStoreReadingRegisters[i][0] = srcReg;	/* Remember that we are reading the source register */
									loadStoreReadingRenameBuffers[i][0] = -1;	/* No rename buffer is being read */
									outReadRegisterNumber[readRegisterPort++] = srcReg;	/* Ask to the register file the source register value */
								}
								else
								{
									/* The source register is renamed */
									
									if(registersBinding->RenameBufferValid(tag))
									{
										/* The rename buffer yet contains the right value */
#ifdef DEBUG
										if(Debug(DebugDispatchUnit))
										{
											cout << name() << ": Reading r" << (int) srcReg << " value from rr" << (int) tag << endl;
											if(readRenamePort >= nReadRenamePorts)
											{
												cout << name() << ": not enough read rename buffer ports" << endl;
												ABORT();
											}
										}
#endif
										loadStoreReadingRegisters[i][0] = -1;			/* No register is being read */
										loadStoreReadingRenameBuffers[i][0] = tag;		/* Remember that we are reading a rename buffer */
										outReadRenameNumber[readRenamePort++] = tag;	/* Ask to the register file the value of the rename buffer */
									}
									else
									{
#ifdef DEBUG
										if(Debug(DebugDispatchUnit))
											cout << name() << ": Waiting for r" << (int) srcReg << " value hold by rr" << (int) tag << endl;
#endif	
										loadStoreReadingRegisters[i][0] = -1;			/* No register is being read */
										loadStoreReadingRenameBuffers[i][0] = -1;		/* No rename buffer is being read */
										/* Just wait for the value to be produced by functional units */
									}
								}
							}
							else
							{
								/* No source register */
								loadStoreReadingRegisters[i][0] = -1;
								loadStoreReadingRenameBuffers[i][0] = -1;
								rs[i].loadStore->operand0.tag = -1;
							}
						}
					
						// operand 1
						srcReg = decodedInstructions[i].io.loadStore.srcReg[1];
						
						if(srcReg >= 0)
						{
							/* Instruction has a source register */
#ifdef DEBUG
							if(Debug(DebugDispatchUnit))
								cout << "source register : r" << (int) srcReg << endl;
#endif
							tag_t tag = registersBinding->GetRenameBuffer(srcReg);	/* Get the rename buffer, */
							rs[i].loadStore->operand1.tag = tag;		/* and store its tag into the reservation station */
							rs[i].loadStore->operand1.valid = false;	/* make the reservation station to wait for the rename buffer */
								
							if(tag < 0)
							{
								 /* The source register is not renamed */
#ifdef DEBUG	
								if(Debug(DebugDispatchUnit))
								{
									cout << name() << ": Reading r" << (int) srcReg << " value from register file" << endl;
									if(readRegisterPort >= nReadRegisterPorts)
									{
										cout << name() << ": not enough read register ports" << endl;
										ABORT();
									}
								}
#endif
								loadStoreReadingRegisters[i][1] = srcReg;	/* Remember that we are reading a register */
								loadStoreReadingRenameBuffers[i][1] = -1;	/* No rename buffer is being read */
								outReadRegisterNumber[readRegisterPort++] = srcReg;	/* Ask to the register the value of the register */
							}
							else
							{
								/* The source register is renamed */
									
								if(registersBinding->RenameBufferValid(tag))
								{
									/* The rename yet contains the right value */
#ifdef DEBUG
									if(Debug(DebugDispatchUnit))
									{
										cout << name() << ": Reading r" << (int) srcReg << " value from rr" << (int) tag << endl;
										if(readRenamePort >= nReadRenamePorts)
										{
											cout << name() << ": not enough read rename buffer ports" << endl;
											ABORT();
										}
									}
#endif
									loadStoreReadingRegisters[i][1] = -1;			/* No register is being read */
									loadStoreReadingRenameBuffers[i][1] = tag;		/* Remember that we are reading the rename buffer */
									outReadRenameNumber[readRenamePort++] = tag;	/* Ask to the register the value of the rename buffer */
								}
								else
								{
#ifdef DEBUG
									if(Debug(DebugDispatchUnit))
										cout << name() << ": Waiting for r" << (int) srcReg << " value hold by rr" << (int) tag << endl;
#endif	
									loadStoreReadingRegisters[i][1] = -1;
									loadStoreReadingRenameBuffers[i][1] = -1;
									/* Just wait for the value to be produced by functional units */
								}
							}
						}
						else
						{
							/* No source register */
							loadStoreReadingRegisters[i][1] = -1;
							loadStoreReadingRenameBuffers[i][1] = -1;
							rs[i].loadStore->operand1.tag = -1;
						}

						// operand 2
						srcReg = decodedInstructions[i].io.loadStore.srcReg[2];
						
						if(srcReg >= 0)
						{
							/* Instruction has a source register */
#ifdef DEBUG
							if(Debug(DebugDispatchUnit))
								cout << "source register : r" << (int) srcReg << endl;
#endif
							tag_t tag = registersBinding->GetRenameBuffer(srcReg);	/* Get the rename buffer, */
							rs[i].loadStore->operand2.tag = tag;		/* and store its tag into the reservation station */
							rs[i].loadStore->operand2.valid = false;	/* make the reservation station to wait for the rename buffer */
								
							if(tag < 0)
							{
								 /* The source register is not renamed */
#ifdef DEBUG	
								if(Debug(DebugDispatchUnit))
								{
									cout << name() << ": Reading r" << (int) srcReg << " value from register file" << endl;
									if(readRegisterPort >= nReadRegisterPorts)
									{
										cout << name() << ": not enough read register ports" << endl;
										ABORT();
									}
								}
#endif
								loadStoreReadingRegisters[i][2] = srcReg;	/* Remember that we are reading the source register */
								loadStoreReadingRenameBuffers[i][2] = -1;	/* No rename buffer is being read */
								outReadRegisterNumber[readRegisterPort++] = srcReg;	/* Ask to the register file the value of the source register */
							}
							else
							{
								/* The source register is renamed */
									
								if(registersBinding->RenameBufferValid(tag))
								{
									/* The rename buffer yet contains the right value */
#ifdef DEBUG
									if(Debug(DebugDispatchUnit))
									{
										cout << name() << ": Reading r" << (int) srcReg << " value from rr" << (int) tag << endl;
										if(readRenamePort >= nReadRenamePorts)
										{
											cout << name() << ": not enough read rename buffer ports" << endl;
											ABORT();
										}
									}
#endif
									loadStoreReadingRegisters[i][2] = -1;		/* No register is being read */
									loadStoreReadingRenameBuffers[i][2] = tag;	/* Remember that we are reading a rename buffer */
									outReadRenameNumber[readRenamePort++] = tag;	/* Ask to the register file the value of the rename buffer */
								}
								else
								{
#ifdef DEBUG
									if(Debug(DebugDispatchUnit))
										cout << name() << ": Waiting for r" << (int) srcReg << " value hold by rr" << (int) tag << endl;
#endif	
									loadStoreReadingRegisters[i][2] = -1;
									loadStoreReadingRenameBuffers[i][2] = -1;
									/* Just wait for the value to be produced by the functional units */
								}
							}
						}
						else
						{
							/* No source operand */
							loadStoreReadingRegisters[i][2] = -1;
							loadStoreReadingRenameBuffers[i][2] = -1;
							rs[i].loadStore->operand2.tag = -1;
						}
												
						
						/* Store the load/store operation into the reservation station */
						rs[i].loadStore->operation = decodedInstructions[i].operation.loadStore;
#if defined(DEBUG) || defined(TRACE)
						{
							const InstructionQueueEntry& instructionQueueEntry = *queue[i];
							rs[i].loadStore->dbgInstructionCounter = instructionQueueEntry.dbgInstructionCounter;
							rs[i].loadStore->dbgProgramCounter = instructionQueueEntry.pc;
							rs[i].loadStore->dbgInstruction = instructionQueueEntry.instruction;
						}
#endif
						if(decodedInstructions[i].hasImmed)
						{
							// store the immediate value into the reservation station
							rs[i].loadStore->operand2.data = decodedInstructions[i].immed;
#ifdef DEBUG
							if(Debug(DebugDispatchUnit))
							{
								cout << "immediate : ";
								WriteHex(cout, decodedInstructions[i].immed);
								cout << endl;
							}
#endif
						}
	
						// destination 0
						if(decodedInstructions[i].operation.loadStore.floatingPoint)
						{
							regnum_t dstReg = decodedInstructions[i].io.loadStore.dstReg[0];
					
							if(dstReg >= 0)
							{
								/* Instruction has a destination floating point register */
#ifdef DEBUG
								if(Debug(DebugDispatchUnit))
									cout << "destination register (0)" << ": fp" << (int) dstReg << endl;
#endif
								/* Allocate a floating point rename buffer, and store its tag into the reservation station */
								rs[i].loadStore->tags.resultTags[0] = registersBinding->AllocateFloatingPointRenameBuffer(dstReg);
							}
							else
							{
								/* Instruction has no destination floating point register */
								rs[i].loadStore->tags.resultTags[0] = -1;
							}
						}
						else
						{
							regnum_t dstReg = decodedInstructions[i].io.loadStore.dstReg[0];
				
							if(dstReg >= 0)
							{
								/* Instruction has a destination register */
#ifdef DEBUG
								if(Debug(DebugDispatchUnit))
									cout << "destination register (0)" << ": r" << (int) dstReg << endl;
#endif
								/* Allocate a rename buffer, and store its tag into the reservation station */
								rs[i].loadStore->tags.resultTags[0] = registersBinding->AllocateRenameBuffer(dstReg);
							}
							else
							{
								/* Instruction has no destination register */
								rs[i].loadStore->tags.resultTags[0] = -1;
							}
						}
						
						// destination 1
						regnum_t dstReg = decodedInstructions[i].io.loadStore.dstReg[1];
					
						if(dstReg >= 0)
						{
							/* Instruction has a destination register */
#ifdef DEBUG
							if(Debug(DebugDispatchUnit))
								cout << "destination register (1)" << ": r" << (int) dstReg << endl;