Merge branch '68000Mk2' into InMacintosh

InstructionSets/M68k/Implementation/PerformImplementation.hpp

@@ -522,17 +522,18 @@ template <
 #define DIV(Type16, Type32, flow_function) {								\
 	status.carry_flag = 0;													\
 																			\
-	if(!src.w) {															\
+	const auto dividend = Type32(dest.l);									\
+	const auto divisor = Type32(Type16(src.w));								\
+																			\
+	if(!divisor) {															\
 		status.negative_flag = status.overflow_flag = 0;					\
 		status.zero_result = 1;												\
 		flow_controller.raise_exception(Exception::IntegerDivideByZero);	\
+		flow_controller.template flow_function<false>(dividend, divisor);	\
 		return;																\
 	}																		\
 																			\
-	const auto dividend = Type32(dest.l);									\
-	const auto divisor = Type32(Type16(src.w));								\
 	const auto quotient = dividend / divisor;								\
-																			\
 	if(quotient != Type32(Type16(quotient))) {								\
 		status.overflow_flag = 1;											\
 		flow_controller.template flow_function<true>(dividend, divisor);	\

InstructionSets/M68k/Instruction.cpp

@@ -61,7 +61,7 @@ std::string Preinstruction::to_string(int opcode) const {
 	const char *instruction;
 
 	switch(operation) {
-		case Operation::Undefined:	instruction = "None";		break;
+		case Operation::Undefined:	return "None";
 		case Operation::NOP:		instruction = "NOP";		break;
 		case Operation::ABCD:		instruction = "ABCD";		break;
 		case Operation::SBCD:		instruction = "SBCD";		break;

InstructionSets/M68k/Status.hpp

@@ -95,6 +95,23 @@ struct Status {
 		return is_supervisor;
 	}
 
+	/// Adjusts the status for exception processing — sets supervisor mode, disables trace,
+	/// and if @c new_interrupt_level is greater than or equal to 0 sets that as the new
+	/// interrupt level.
+	///
+	/// @returns The status prior to those changes.
+	uint16_t begin_exception(int new_interrupt_level = -1) {
+		const uint16_t initial_status = status();
+
+		if(new_interrupt_level >= 0) {
+			interrupt_level = new_interrupt_level;
+		}
+		is_supervisor = true;
+		trace_flag = 0;
+
+		return initial_status;
+	}
+
 	/// Evaluates @c condition.
 	bool evaluate_condition(Condition condition) {
 		switch(condition) {

OSBindings/Mac/Clock SignalTests/68000ArithmeticTests.mm

@@ -726,7 +726,7 @@
 }
 
 - (void)performDIVS:(uint16_t)divisor d1:(uint32_t)d1 {
-	[self performDIVS:divisor d1:d1];
+	[self performDIVS:divisor d1:d1 sp:0];
 }
 
 - (void)performDIVSOverflowTestDivisor:(uint16_t)divisor {
@@ -734,7 +734,12 @@
 
 	const auto state = self.machine->get_processor_state();
 	XCTAssertEqual(state.registers.data[1], 0x4768f231);
-	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend | ConditionCode::Negative | ConditionCode::Overflow);
+
+	// N and Z are officially undefined upon DIVS overflow, and I've found no
+	// other relevant information.
+	XCTAssertEqual(
+		state.registers.status & (ConditionCode::Extend | ConditionCode::Overflow | ConditionCode::Carry),
+		ConditionCode::Extend | ConditionCode::Overflow);
 	XCTAssertEqual(20, self.machine->get_cycle_count());
 }
 
@@ -865,7 +870,7 @@
 	XCTAssertEqual(state.registers.data[1], 0x1fffffff);
 	XCTAssertEqual(state.registers.supervisor_stack_pointer, initial_sp - 6);
 	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend);
-	XCTAssertEqual(42, self.machine->get_cycle_count());
+	XCTAssertEqual(44, self.machine->get_cycle_count());
 
 	// Check stack contents; should be PC.l, PC.h and status register.
 	// Assumed: the program counter on the stack is that of the

OSBindings/Mac/Clock SignalTests/68000ControlFlowTests.mm

@@ -157,41 +157,48 @@
 	XCTAssertEqual(state.registers.data[2], d2);
 }
 
+// Re: CHK, below; the final state of N is undocumented if Dn >= 0 and Dn < <ea>.
+// Z, V and C are also undocumented by Motorola, but are documneted by 68knotes.txt.
+
 - (void)testCHK_1111v1111 {
-	[self performCHKd1:0x1111 d2:0x1111];
+	[self performCHKd1:0x1111 d2:0x1111];		// Neither exception-generating state applies.
 
 	const auto state = _machine->get_processor_state();
 	XCTAssertEqual(state.registers.program_counter, 0x1002 + 4);
-	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend);
+	XCTAssertEqual(
+		state.registers.status & (ConditionCode::Extend | ConditionCode::Zero | ConditionCode::Overflow | ConditionCode::Carry),
+		ConditionCode::Extend);
 	XCTAssertEqual(10, _machine->get_cycle_count());
 }
 
 - (void)testCHK_1111v0000 {
-	[self performCHKd1:0x1111 d2:0x0000];
+	[self performCHKd1:0x1111 d2:0x0000];		// Neither exception-generating state applies.
 
 	const auto state = _machine->get_processor_state();
 	XCTAssertEqual(state.registers.program_counter, 0x1002 + 4);
-	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend | ConditionCode::Zero);
+	XCTAssertEqual(
+		state.registers.status & (ConditionCode::Extend | ConditionCode::Zero | ConditionCode::Overflow | ConditionCode::Carry),
+		ConditionCode::Extend | ConditionCode::Zero);
 	XCTAssertEqual(10, _machine->get_cycle_count());
 }
 
 - (void)testCHK_8000v8001 {
-	[self performCHKd1:0x8000 d2:0x8001];
+	[self performCHKd1:0x8000 d2:0x8001];		// Both less than 0 and D2 greater than D1.
 
 	const auto state = _machine->get_processor_state();
 	XCTAssertNotEqual(state.registers.program_counter, 0x1002 + 4);
 	XCTAssertEqual(state.registers.stack_pointer(), 0xfffffffa);
-	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend);
+	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend | ConditionCode::Negative);
-	XCTAssertEqual(42, _machine->get_cycle_count());
+	XCTAssertEqual(38, _machine->get_cycle_count());
 }
 
 - (void)testCHK_8000v8000 {
-	[self performCHKd1:0x8000 d2:0x8000];
+	[self performCHKd1:0x8000 d2:0x8000];		// Less than 0.
 
 	const auto state = _machine->get_processor_state();
 	XCTAssertNotEqual(state.registers.program_counter, 0x1002 + 4);
 	XCTAssertEqual(state.registers.status & ConditionCode::AllConditions, ConditionCode::Extend | ConditionCode::Negative);
-	XCTAssertEqual(44, _machine->get_cycle_count());
+	XCTAssertEqual(40, _machine->get_cycle_count());
 }
 
 // MARK: DBcc

Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp

@@ -91,12 +91,16 @@ enum ExecutionState: int {
 	CalcAddressRegisterIndirectWithPostincrement,					// -
 	CalcAddressRegisterIndirectWithPredecrement,					// -
 	CalcAddressRegisterIndirectWithDisplacement,					// np
-	CalcAddressRegisterIndirectWithIndex8bitDisplacement,			// n np n
+	CalcAddressRegisterIndirectWithIndex8bitDisplacement,			// np n
 	CalcProgramCounterIndirectWithDisplacement,						// np
-	CalcProgramCounterIndirectWithIndex8bitDisplacement,			// n np n
+	CalcProgramCounterIndirectWithIndex8bitDisplacement,			// np n
 	CalcAbsoluteShort,												// np
 	CalcAbsoluteLong,												// np np
 
+	CalcEffectiveAddressIdleFor8bitDisplacement,					// As per CalcEffectiveAddress unless one of the
+																	// 8-bit displacement modes is in use, in which case
+																	// an extra idle bus state is prefixed.
+
 	// Various forms of perform; each of these will
 	// perform the current instruction, then do the
 	// indicated bus cycle.
@@ -355,9 +359,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			IdleBus(7);			// (n-)*5   nn
 
 			// Establish general reset state.
-			status_.is_supervisor = true;
+			status_.begin_exception(7);
-			status_.interrupt_level = 7;
-			status_.trace_flag = 0;
 			should_trace_ = 0;
 			did_update_status();
 
@@ -383,11 +385,8 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 		// Perform a 'standard' exception, i.e. a Group 1 or 2.
 		BeginState(StandardException):
-			captured_status_.w = status_.status();
-
 			// Switch to supervisor mode, disable interrupts.
-			status_.is_supervisor = true;
+			captured_status_.w = status_.begin_exception();
-			status_.trace_flag = 0;
 			should_trace_ = 0;
 			did_update_status();
 
@@ -451,13 +450,10 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			//	4) function code;
 			//	5) access address?
 
-			captured_status_.w = status_.status();
 			IdleBus(2);
 
 			// Switch to supervisor mode, disable interrupts.
-			status_.is_supervisor = true;
+			captured_status_.w = status_.begin_exception(7);
-			status_.trace_flag = 0;
-			status_.interrupt_level = 7;
 			should_trace_ = 0;
 			did_update_status();
 
@@ -515,10 +511,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			IdleBus(3);			// n nn
 
 			// Capture status and switch to supervisor mode.
-			captured_status_.w = status_.status();
+			captured_status_.w = status_.begin_exception(captured_interrupt_level_);
-			status_.is_supervisor = true;
-			status_.trace_flag = 0;
-			status_.interrupt_level = captured_interrupt_level_;
 			should_trace_ = 0;
 			did_update_status();
 
@@ -602,18 +595,21 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 				bus_handler_.will_perform(instruction_address_.l, opcode_);
 			}
 
-			// Check for a privilege violation.
-			if(instruction_.requires_supervisor() && !status_.is_supervisor) {
-				exception_vector_ = InstructionSet::M68k::Exception::PrivilegeViolation;
-				MoveToStateSpecific(StandardException);
-			}
-
 			// Ensure the first parameter is next fetched.
 			next_operand_ = 0;
 
-			// Obtain operand flags and pick a perform pattern.
+			/// If operation x requires supervisor privileges, checks whether the user is currently in supervisor mode;
-#define CASE(x)	\
+			/// if not then raises a privilege violation exception.
-	case InstructionSet::M68k::Operation::x:																								\
+#define CheckSupervisor(x)																													\
+		if constexpr (InstructionSet::M68k::requires_supervisor<InstructionSet::M68k::Model::M68000>(InstructionSet::M68k::Operation::x)) {	\
+			if(!status_.is_supervisor) {																									\
+				RaiseException(InstructionSet::M68k::Exception::PrivilegeViolation);														\
+			}																																\
+		}
+
+#define CASE(x)									\
+	case InstructionSet::M68k::Operation::x:	\
+		CheckSupervisor(x);						\
 		operand_flags_ = InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::x>();
 
 #define StdCASE(x, y)	\
@@ -635,14 +631,16 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 #define Duplicate(x, y)	\
 	case InstructionSet::M68k::Operation::x:	\
 		static_assert(	\
-			InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::x>() ==	\
+			InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::x>() ==		\
-			InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::y>() &&	\
+			InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::y>() &&		\
-			InstructionSet::M68k::operand_size<InstructionSet::M68k::Operation::x>() == 										\
+			InstructionSet::M68k::operand_size<InstructionSet::M68k::Operation::x>() == 											\
-			InstructionSet::M68k::operand_size<InstructionSet::M68k::Operation::y>()											\
+			InstructionSet::M68k::operand_size<InstructionSet::M68k::Operation::y>() &&												\
-		);																														\
+			InstructionSet::M68k::requires_supervisor<InstructionSet::M68k::Model::M68000>(InstructionSet::M68k::Operation::x) == 	\
+			InstructionSet::M68k::requires_supervisor<InstructionSet::M68k::Model::M68000>(InstructionSet::M68k::Operation::y)		\
+		);																															\
 		[[fallthrough]];
 
-#define SpecialCASE(x)	case InstructionSet::M68k::Operation::x: MoveToStateSpecific(x)
+#define SpecialCASE(x)	case InstructionSet::M68k::Operation::x: CheckSupervisor(x); MoveToStateSpecific(x)
 
 			switch(instruction_.operation) {
 				case InstructionSet::M68k::Operation::Undefined:
@@ -698,7 +696,9 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 				StdCASE(CMPb,		perform_state_ = Perform_np);
 				StdCASE(CMPw,		perform_state_ = Perform_np);
-				StdCASE(CMPl,		perform_state_ = Perform_np_n);
+				StdCASE(CMPl,
+					perform_state_ = instruction_.mode(1) == Mode::DataRegisterDirect ? Perform_np_n : Perform_np
+				);
 
 				StdCASE(CMPAw,		perform_state_ = Perform_np_n);
 				StdCASE(CMPAl,		perform_state_ = Perform_np_n);
@@ -747,18 +747,25 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 				Duplicate(SUBb, ADDb)	StdCASE(ADDb,		perform_state_ = Perform_np)
 				Duplicate(SUBw, ADDw)	StdCASE(ADDw,		perform_state_ = Perform_np)
 				Duplicate(SUBl, ADDl)	StdCASE(ADDl, {
-					if(instruction_.mode(1) != Mode::DataRegisterDirect) {
+					if(instruction_.mode(0) == Mode::Quick) {
-						perform_state_ = Perform_np;
+						perform_state_ = (
+							instruction_.mode(1) == Mode::AddressRegisterDirect ||
+							instruction_.mode(1) == Mode::DataRegisterDirect
+						) ? Perform_np_nn : Perform_np;
 					} else {
-						switch(instruction_.mode(0)) {
+						if(instruction_.mode(1) != Mode::DataRegisterDirect) {
-							default:
+							perform_state_ = Perform_np;
-								perform_state_ = Perform_np_n;
+						} else {
-							break;
+							switch(instruction_.mode(0)) {
-							case Mode::DataRegisterDirect:
+								default:
-							case Mode::AddressRegisterDirect:
+									perform_state_ = Perform_np_n;
-							case Mode::ImmediateData:
+								break;
-								perform_state_ = Perform_np_nn;
+								case Mode::DataRegisterDirect:
-							break;
+								case Mode::AddressRegisterDirect:
+								case Mode::ImmediateData:
+									perform_state_ = Perform_np_nn;
+								break;
+							}
 						}
 					}
 				})
@@ -922,11 +929,11 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 				StdCASE(LEA, {
 					post_ea_state_ = LEA;
-					MoveToStateSpecific(CalcEffectiveAddress);
+					MoveToStateSpecific(CalcEffectiveAddressIdleFor8bitDisplacement);
 				});
 				StdCASE(PEA, {
 					post_ea_state_ = PEA;
-					MoveToStateSpecific(CalcEffectiveAddress);
+					MoveToStateSpecific(CalcEffectiveAddressIdleFor8bitDisplacement);
 				});
 
 				StdCASE(TAS, {
@@ -936,13 +943,13 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 					// for the other cases.
 					if(instruction_.mode(0) != Mode::DataRegisterDirect) {
 						post_ea_state_ = TAS;
-						MoveToStateSpecific(CalcEffectiveAddress);
+						MoveToStateSpecific(CalcEffectiveAddressIdleFor8bitDisplacement);
 					}
 
 					perform_state_ = Perform_np;
 				});
 
-				Duplicate(MOVEtoCCR, MOVEtoSR);
+				StdCASE(MOVEtoCCR, 	perform_state_ = MOVEtoCCRSR);
 				StdCASE(MOVEtoSR, 	perform_state_ = MOVEtoCCRSR);
 				StdCASE(MOVEfromSR, {
 					if(instruction_.mode(0) == Mode::DataRegisterDirect) {
@@ -994,6 +1001,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 #undef StdCASE
 #undef CASE
 #undef SpecialCASE
+#undef CheckSupervisor
 
 	// MARK: - Fetch, dispatch.
 
@@ -1098,6 +1106,17 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			}
 		break;
 
+		BeginState(CalcEffectiveAddressIdleFor8bitDisplacement):
+			if(
+				instruction_.mode(next_operand_) != Mode::AddressRegisterIndirectWithIndex8bitDisplacement &&
+				instruction_.mode(next_operand_) != Mode::ProgramCounterIndirectWithIndex8bitDisplacement
+			) {
+				MoveToStateSpecific(CalcEffectiveAddress);
+			}
+
+			IdleBus(1);
+			[[fallthrough]];
+
 		BeginState(CalcEffectiveAddress):
 			switch(instruction_.mode(next_operand_)) {
 				default:
@@ -1323,7 +1342,6 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 		BeginState(CalcAddressRegisterIndirectWithIndex8bitDisplacement):
 			effective_address_[next_operand_].l = d8Xn(registers_[8 + instruction_.reg(next_operand_)].l);
-			IdleBus(1);								// n
 			Prefetch();								// np
 			IdleBus(1);								// n
 		MoveToStateDynamic(post_ea_state_);
@@ -1359,7 +1377,6 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 		BeginState(CalcProgramCounterIndirectWithIndex8bitDisplacement):
 			effective_address_[next_operand_].l = d8Xn(program_counter_.l - 2);
-			IdleBus(1);								// n
 			Prefetch();								// np
 			IdleBus(1);								// n
 		MoveToStateDynamic(post_ea_state_);