PTO-SCALAR-MODEL-DISPATCH-TOP-LEVEL

1// PTO-UNIT: {"id":"PTO-SCALAR-MODEL-DISPATCH-TOP-LEVEL","surface":"scalar","classification":["model","dispatch","top-level"],"depends_on":["PTO-SCALAR-MODEL-DISPATCH-ALU","PTO-SCALAR-MODEL-DISPATCH-BRU","PTO-SCALAR-MODEL-DISPATCH-SYS","PTO-SCALAR-MODEL-DISPATCH-AMO","PTO-SCALAR-MODEL-DISPATCH-AGU","PTO-SCALAR-MODEL-DISPATCH-FSU"],"catalog_projection":{"catalog":"scalar-forms","family_constraints":[],"isa":"PTO Instruction Set Architecture","schema_version":2}}2func ExecuteScalarInstruction(instruction: bits(48),3                              length_bits: integer {16,32,48})4                              => ScalarExecutionStatus5begin6    BeginArchitecturalInstructionAttempt();7    let decoded = DecodeScalarForm(instruction, length_bits);8    if decoded == PTO_SCALAR_FORM_COUNT then9        SetFault(Fault_IllegalInstruction, ReadPC());10        return ScalarExecution_Rejected;11    end;12    let form = decoded as integer {0..PTO_SCALAR_FORM_COUNT-1};13    let operation = ScalarOperationOfForm(form);14    if !ScalarOperationApplicable(operation) then15        SetFault(Fault_BundleControl, ReadTPC());16        return ScalarExecution_Rejected;17    end;18    if !ScalarFormOperandsLegal(instruction, form) then19        SetFault(Fault_IllegalInstruction, ReadPC());20        return ScalarExecution_Rejected;21    end;22    if !ScalarRegisterOperandsLegal(instruction, form) then23        SetFault(Fault_IllegalInstruction, ReadPC());24        return ScalarExecution_Rejected;25    end;26    if !ScalarImplicitSourceOperandsLegal(operation) then27        SetFault(Fault_IllegalInstruction, ReadPC());28        return ScalarExecution_Rejected;29    end;30    case ScalarFamilyOfForm(form) of31        when ScalarSemantic_AGU => ExecuteDecodedAGUForm(instruction, form);32        when ScalarSemantic_ALU => ExecuteDecodedALUForm(instruction, form);33        when ScalarSemantic_AMO => ExecuteDecodedAMOForm(instruction, form);34        when ScalarSemantic_BRU => ExecuteDecodedBRUForm(instruction, form);35        when ScalarSemantic_FSU => ExecuteDecodedFSUForm(instruction, form);36        when ScalarSemantic_SYS => ExecuteDecodedSYSForm(instruction, form);37        otherwise => unreachable;38    end;39    if _LastFault != Fault_None then40        return ScalarExecution_Rejected;41    end;42    if !ScalarHandlerWritesTPC(ScalarHandlerOfForm(form)) then43        WriteTPC(ReadTPC() + NaturalToWord(length_bits DIV 8));44    end;45    return ScalarExecution_Executed;46end;47