func (this *ReorderBuffer) LoadData(op *operation.Operation, address uint32) uint32 {
robEntry, ok := this.getEntryByDestination(op.Id(), MemoryType, address)
if ok {
return uint32(robEntry.Value)
}
return this.Processor().DataMemory().LoadUint32(address)
}
func (this *ReorderBuffer) SetProgramCounter(op *operation.Operation, value uint32) {
this.Buffer()[op.Id()] = RobEntry{
Operation: op,
Type: ProgramCounterType,
Destination: AbsoluteType,
Value: int32(value),
Cycle: this.Processor().Cycles(),
}
}
func (this *ReorderBuffer) IncrementProgramCounter(op *operation.Operation, value int32) {
this.Buffer()[op.Id()] = RobEntry{
Operation: op,
Type: ProgramCounterType,
Destination: OffsetType,
Value: value,
Cycle: this.Processor().Cycles(),
}
}
func (this *ReorderBuffer) StoreData(op *operation.Operation, address, value uint32) {
this.Buffer()[op.Id()] = RobEntry{
Operation: op,
Type: MemoryType,
Destination: address,
Value: int32(value),
Cycle: this.Processor().Cycles(),
}
}
func (this *ReorderBuffer) StoreRegister(op *operation.Operation, index, value uint32) {
dest := index
// If renaming register enabled
if op.RenamedDestRegister() != -1 {
dest = uint32(op.RenamedDestRegister())
}
this.Buffer()[op.Id()] = RobEntry{
Operation: op,
Type: RegisterType,
Destination: dest,
Value: int32(value),
Cycle: this.Processor().Cycles(),
}
}
func (this *ReservationStation) dispatchOperation(entryIndex EntryIndex, op *operation.Operation) {
// Lock a slot in max quantity of instructions dispatcher per cycle
this.AddInstructionsFetchedStack()
// Release reservation station entry
this.Entries()[entryIndex].Busy = true
go func() {
// Release one entry and send operation to execution, when output channel (execution unit) is free
logger.Collect(" => [RS%d][%03d]: Sending entry %d to %s queue...", this.Index(), op.Id(), entryIndex, op.Instruction().Info.Category)
// Wait dispatch cycles
startCycles := this.Processor().Cycles()
this.Processor().Wait(consts.DISPATCH_CYCLES)
// Log completion
this.Processor().LogEvent(consts.DISPATCH_EVENT, this.Index(), op.Id(), startCycles)
// Send data to execution unit in a go routine, when execution unit is available
go this.Output()[op.Instruction().Info.Category].Add(op)
}()
}
func (this *Decoder) decodeInstruction(op *operation.Operation) (*instruction.Instruction, error) {
startCycles := this.Processor().Cycles()
// Do decode once a data instruction is received
instruction, err := this.Processor().InstructionsSet().GetInstructionFromBytes(op.Word())
if err != nil {
return nil, errors.New(fmt.Sprintf("Failed decoding instruction %#04X. %s]", op.Word(), err.Error()))
}
logger.Collect(" => [DE%d][%03d]: %#04X = %s, %s", this.Index(), op.Id(), op.Word(), instruction.Info.ToString(), instruction.Data.ToString())
// Wait cycles of a decode stage
this.Processor().Wait(consts.DECODE_CYCLES)
// Log event
if this.IsActive() {
this.Processor().LogEvent(consts.DECODE_EVENT, this.Index(), op.Id(), startCycles)
}
return instruction, nil
}
func (this *Executor) executeOperation(unit IExecutor, event string, op *operation.Operation) (*operation.Operation, error) {
startCycles := this.Processor().Cycles()
// Do decode once a data instruction is received
var err error
op, err = unit.Process(op)
if err != nil {
return op, errors.New(fmt.Sprintf("Failed executing instruction. %s]", err.Error()))
}
// Wait cycles of a execution stage
logger.Collect(" => [%s%d][%03d]: Executing %s, %s", event, this.Index(), op.Id(), op.Instruction().Info.ToString(), op.Instruction().Data.ToString())
for i := uint8(0); i < op.Instruction().Info.Cycles; i++ {
this.Processor().Wait(1)
}
// Log completion
if this.IsActive() {
this.Processor().LogEvent(event, this.Index(), op.Id(), startCycles)
}
return op, nil
}
func (this *Fpu) Process(operation *operation.Operation) (*operation.Operation, error) {
instruction := operation.Instruction()
outputAddress, err := this.compute(operation, instruction.Info, instruction.Data)
if err != nil {
return operation, err
}
logger.Collect(" => [FPU][%03d]: [R%d(%#02X) = %#08X]", operation.Id(), outputAddress, outputAddress*consts.BYTES_PER_WORD, this.Result())
// Persist output data
this.Bus().StoreRegister(operation, outputAddress, this.Result())
return operation, nil
}
func (this *ReorderBuffer) LoadRegister(op *operation.Operation, index uint32) uint32 {
lookupRegister := index
// If renaming register enabled
if len(this.RegisterAliasTable().Entries()) > 0 {
ratEntry, ok := this.RegisterAliasTable().GetPhysicalRegister(op.Id()-1, index)
if ok {
// Proceed to search register in ROB with renamed dest from RAT
lookupRegister = ratEntry
} else {
// Alias does not exist, value was already commited (search on memory)
return this.Processor().RegistersMemory().LoadUint32(index * consts.BYTES_PER_WORD)
}
}
// Search register on ROB
robEntry, ok := this.getEntryByDestination(op.Id(), RegisterType, lookupRegister)
if ok {
return uint32(robEntry.Value)
}
return this.Processor().RegistersMemory().LoadUint32(index * consts.BYTES_PER_WORD)
}
func (this *Branch) Process(operation *operation.Operation) (*operation.Operation, error) {
instruction := operation.Instruction()
info := instruction.Info
operands := instruction.Data
switch info.Type {
case data.TypeI:
registerD := operands.(*data.DataI).RegisterD.ToUint32()
op1 := this.Bus().LoadRegister(operation, registerD)
registerS := operands.(*data.DataI).RegisterS.ToUint32()
op2 := this.Bus().LoadRegister(operation, registerS)
logger.Collect(" => [BR][%03d]: [R%d(%#02X) = %#08X ? R%d(%#02X) = %#08X]",
operation.Id(), registerD, registerD*consts.BYTES_PER_WORD, op1, registerS, registerS*consts.BYTES_PER_WORD, op2)
taken, err := processOperation(op1, op2, info.Opcode)
if err != nil {
return operation, nil
}
operation.SetBranchResult(taken)
if taken {
offsetAddress := ComputeOffsetTypeI(operands)
this.Bus().IncrementProgramCounter(operation, offsetAddress)
logger.Collect(" => [BR][%03d]: [PC(offset) = 0x%06X", operation.Id(), offsetAddress)
} else {
// Notify ROB
this.Bus().IncrementProgramCounter(operation, 0)
}
case data.TypeJ:
address := ComputeAddressTypeJ(operands)
this.Bus().SetProgramCounter(operation, uint32(address-consts.BYTES_PER_WORD))
logger.Collect(" => [BR][%03d]: [Address = %06X]", operation.Id(), address)
default:
return operation, errors.New(fmt.Sprintf("Invalid data type to process by Branch unit. Type: %d", info.Type))
}
return operation, nil
}
func (this *ReorderBuffer) waitStallOperationIfFull(op *operation.Operation) {
for uint32(len(this.Buffer())) >= this.RobEntries() {
lastCompletedOpId := this.Processor().LastOperationIdCompleted()
if op.Id() == lastCompletedOpId+1 {
logger.Collect(" => [RB%d][%03d]: Writing latest instruction.", this.Index(), op.Id())
return
}
logger.Collect(" => [RB%d][%03d]: ROB is full, wait for free entries. Current: %d, Max: %d, LastOpId: %d...",
this.Index(), op.Id(), len(this.Buffer()), this.RobEntries(), lastCompletedOpId)
this.Processor().Wait(1)
}
}
func (this *Alu) Process(operation *operation.Operation) (*operation.Operation, error) {
instruction := operation.Instruction()
// Clean Status
this.CleanStatus()
outputAddress, err := this.compute(operation, instruction.Info, instruction.Data)
if err != nil {
return operation, err
}
logger.Collect(" => [ALU][%03d]: [R%d(%#02X) = %#08X]", operation.Id(), outputAddress, outputAddress*consts.BYTES_PER_WORD, this.Result())
// Set status flags
this.SetStatusFlag(this.Result()%2 == 0, consts.FLAG_PARITY)
this.SetStatusFlag(this.Result() == 0, consts.FLAG_ZERO)
this.SetStatusFlag(getSign(this.Result()), consts.FLAG_SIGN)
// Persist output data
this.Bus().StoreRegister(operation, outputAddress, this.Result())
return operation, nil
}
func (this *LoadStore) Process(operation *operation.Operation) (*operation.Operation, error) {
instruction := operation.Instruction()
rdAddress := instruction.Data.(*data.DataI).RegisterD.ToUint32()
rsAddress := instruction.Data.(*data.DataI).RegisterS.ToUint32()
immediate := instruction.Data.(*data.DataI).Immediate.ToUint32()
switch instruction.Info.Opcode {
case set.OP_LW:
rsValue := this.Bus().LoadRegister(operation, rsAddress)
value := this.Bus().LoadData(operation, rsValue+immediate)
this.Bus().StoreRegister(operation, rdAddress, value)
logger.Collect(" => [LS][%03d]: [R%d(%#02X) = MEM(%#02X) = %#08X]", operation.Id(), rdAddress, rdAddress*consts.BYTES_PER_WORD, rsValue+immediate, value)
case set.OP_SW:
rdValue := this.Bus().LoadRegister(operation, rdAddress)
rsValue := this.Bus().LoadRegister(operation, rsAddress)
this.Bus().StoreData(operation, rdValue+immediate, rsValue)
logger.Collect(" => [LS][%03d]: [MEM(%#02X) = %#08X]", operation.Id(), rdValue+immediate, rsValue)
case set.OP_LLI:
this.Bus().StoreRegister(operation, rdAddress, immediate)
logger.Collect(" => [LS][%03d]: [R%d(%#02X) = %#08X]", operation.Id(), rdAddress, rdAddress*consts.BYTES_PER_WORD, immediate)
case set.OP_SLI:
rdValue := this.Bus().LoadRegister(operation, rdAddress)
this.Bus().StoreData(operation, rdValue, immediate)
logger.Collect(" => [LS][%03d]: [MEM(%#02X) = %#08X]", operation.Id(), rdValue, immediate)
case set.OP_LUI:
this.Bus().StoreRegister(operation, rdAddress, immediate<<16)
logger.Collect(" => [LS][%03d]: [R%d(%#02X) = %#08X]", operation.Id(), rdAddress, rdAddress*consts.BYTES_PER_WORD, immediate<<16)
case set.OP_SUI:
rdValue := this.Bus().LoadRegister(operation, rdAddress)
this.Bus().StoreData(operation, rdValue, immediate<<16)
logger.Collect(" => [LS][%03d]: [MEM(%#02X) = %#08X]", operation.Id(), rdValue, immediate<<16)
default:
return operation, errors.New(fmt.Sprintf("Invalid operation to process by Data unit. Opcode: %d", instruction.Info.Opcode))
}
return operation, nil
}