Formalise a separate manager of segments.

InstructionSets/x86/Implementation/PerformImplementation.hpp

@@ -256,13 +256,13 @@ template <
 		case Operation::LDS:
 			if constexpr (data_size == DataSize::Word) {
 				Primitive::ld<Source::DS>(instruction, destination_w(), context);
-				context.registers.did_update(Source::DS);
+				context.segments.did_update(Source::DS);
 			}
 		return;
 		case Operation::LES:
 			if constexpr (data_size == DataSize::Word) {
 				Primitive::ld<Source::ES>(instruction, destination_w(), context);
-				context.registers.did_update(Source::ES);
+				context.segments.did_update(Source::ES);
 			}
 		return;
 
@@ -270,7 +270,7 @@ template <
 		case Operation::MOV:
 			Primitive::mov<IntT>(destination_w(), source_r());
 			if constexpr (std::is_same_v<IntT, uint16_t>) {
-				context.registers.did_update(instruction.destination().source());
+				context.segments.did_update(instruction.destination().source());
 			}
 		break;
 
@@ -341,7 +341,7 @@ template <
 		case Operation::POP:
 			destination_w() = Primitive::pop<IntT, false>(context);
 			if constexpr (std::is_same_v<IntT, uint16_t>) {
-				context.registers.did_update(instruction.destination().source());
+				context.segments.did_update(instruction.destination().source());
 			}
 		break;
 		case Operation::PUSH:
@@ -349,10 +349,26 @@ template <
 																	// hence PUSH is sometimes read-modify-write.
 		break;
 
-		case Operation::POPF:	Primitive::popf(context);			return;
+		case Operation::POPF:
-		case Operation::PUSHF:	Primitive::pushf(context);			return;
+			if constexpr (std::is_same_v<IntT, uint16_t> || std::is_same_v<IntT, uint32_t>) {
-		case Operation::POPA:	Primitive::popa<IntT>(context);		return;
+				Primitive::popf(context);
-		case Operation::PUSHA:	Primitive::pusha<IntT>(context);	return;
+			}
+		return;
+		case Operation::PUSHF:
+			if constexpr (std::is_same_v<IntT, uint16_t> || std::is_same_v<IntT, uint32_t>) {
+				Primitive::pushf(context);
+			}
+		return;
+		case Operation::POPA:
+			if constexpr (std::is_same_v<IntT, uint16_t> || std::is_same_v<IntT, uint32_t>) {
+				Primitive::popa<IntT>(context);
+			}
+		return;
+		case Operation::PUSHA:
+			if constexpr (std::is_same_v<IntT, uint16_t> || std::is_same_v<IntT, uint32_t>) {
+				Primitive::pusha<IntT>(context);
+			}
+		return;
 
 		case Operation::CMPS:
 			Primitive::cmps<IntT, AddressT, Repetition::None>(instruction, eCX(), eSI(), eDI(), context);

InstructionSets/x86/Implementation/Stack.hpp

@@ -95,7 +95,6 @@ template <typename IntT, typename ContextT>
 void popa(
 	ContextT &context
 ) {
-	if constexpr (!std::is_same_v<IntT, uint8_t>) {
 	context.memory.preauthorise_stack_read(sizeof(IntT) * 8);
 	if constexpr (std::is_same_v<IntT, uint32_t>) {
 		context.registers.edi() = pop<uint32_t, true>(context);
@@ -116,14 +115,12 @@ void popa(
 		context.registers.cx() = pop<uint16_t, true>(context);
 		context.registers.ax() = pop<uint16_t, true>(context);
 	}
-	}
 }
 
 template <typename IntT, typename ContextT>
 void pusha(
 	ContextT &context
 ) {
-	if constexpr (!std::is_same_v<IntT, uint8_t>) {
 	context.memory.preauthorise_stack_read(sizeof(IntT) * 8);
 	IntT initial_sp = context.registers.sp();
 	if constexpr (std::is_same_v<IntT, uint32_t>) {
@@ -145,7 +142,6 @@ void pusha(
 		push<uint16_t, true>(context.registers.si(), context);
 		push<uint16_t, true>(context.registers.si(), context);
 	}
-	}
 }
 
 }

OSBindings/Mac/Clock SignalTests/8088Tests.mm

@@ -68,7 +68,6 @@ struct Registers {
 	uint16_t &di()	{	return di_;				}
 
 	uint16_t es_, cs_, ds_, ss_;
-	uint32_t es_base_, cs_base_, ds_base_, ss_base_;
 
 	uint16_t ip_;
 	uint16_t &ip()	{	return ip_;				}
@@ -78,17 +77,10 @@ struct Registers {
 	uint16_t &ds()	{	return ds_;				}
 	uint16_t &ss()	{	return ss_;				}
 
-	using Source = InstructionSet::x86::Source;
+	const uint16_t es() const	{	return es_;				}
-	/// Posted by @c perform after any operation which *might* have affected a segment register.
+	const uint16_t cs() const	{	return cs_;				}
-	void did_update(Source segment) {
+	const uint16_t ds() const	{	return ds_;				}
-		switch(segment) {
+	const uint16_t ss() const	{	return ss_;				}
-			default: break;
-			case Source::ES:	es_base_ = es_ << 4;	break;
-			case Source::CS:	cs_base_ = cs_ << 4;	break;
-			case Source::DS:	ds_base_ = ds_ << 4;	break;
-			case Source::SS:	ss_base_ = ss_ << 4;	break;
-		}
-	}
 
 	bool operator ==(const Registers &rhs) const {
 		return
@@ -104,19 +96,52 @@ struct Registers {
 			cs_ == rhs.cs_ &&
 			ds_ == rhs.ds_ &&
 			si_ == rhs.si_ &&
-			ip_ == rhs.ip_ &&
+			ip_ == rhs.ip_;
-			es_base_ == rhs.es_base_ &&
-			cs_base_ == rhs.cs_base_ &&
-			ds_base_ == rhs.ds_base_ &&
-			ss_base_ == rhs.ss_base_;
 	}
 };
+class Segments {
+	public:
+		Segments(const Registers &registers) : registers_(registers) {}
+
+		using Source = InstructionSet::x86::Source;
+
+		/// Posted by @c perform after any operation which *might* have affected a segment register.
+		void did_update(Source segment) {
+			switch(segment) {
+				default: break;
+				case Source::ES:	es_base_ = registers_.es() << 4;	break;
+				case Source::CS:	cs_base_ = registers_.cs() << 4;	break;
+				case Source::DS:	ds_base_ = registers_.ds() << 4;	break;
+				case Source::SS:	ss_base_ = registers_.ss() << 4;	break;
+			}
+		}
+
+		void reset() {
+			did_update(Source::ES);
+			did_update(Source::CS);
+			did_update(Source::DS);
+			did_update(Source::SS);
+		}
+
+		uint32_t es_base_, cs_base_, ds_base_, ss_base_;
+
+		bool operator ==(const Segments &rhs) const {
+			return
+				es_base_ != rhs.es_base_ &&
+				cs_base_ != rhs.cs_base_ &&
+				ds_base_ != rhs.ds_base_ &&
+				ss_base_ != rhs.ss_base_;
+		}
+
+	private:
+		const Registers &registers_;
+};
 struct Memory {
 	public:
 		using AccessType = InstructionSet::x86::AccessType;
 
 		// Constructor.
-		Memory(Registers &registers) : registers_(registers) {
+		Memory(Registers &registers, const Segments &segments) : registers_(registers), segments_(segments) {
 			memory.resize(1024*1024);
 		}
 
@@ -237,6 +262,7 @@ struct Memory {
 		std::unordered_map<uint32_t, Tag> tags;
 		std::vector<uint8_t> memory;
 		const Registers &registers_;
+		const Segments &segments_;
 
 		void preauthorise(uint32_t address) {
 			preauthorisations.insert(address);
@@ -256,10 +282,10 @@ struct Memory {
 		uint32_t segment_base(InstructionSet::x86::Source segment) {
 			using Source = InstructionSet::x86::Source;
 			switch(segment) {
-				default:			return registers_.ds_base_;
+				default:			return segments_.ds_base_;
-				case Source::ES:	return registers_.es_base_;
+				case Source::ES:	return segments_.es_base_;
-				case Source::CS:	return registers_.cs_base_;
+				case Source::CS:	return segments_.cs_base_;
-				case Source::SS:	return registers_.ss_base_;
+				case Source::SS:	return segments_.ss_base_;
 			}
 		}
 
@@ -339,8 +365,8 @@ struct IO {
 };
 class FlowController {
 	public:
-		FlowController(Memory &memory, Registers &registers, Flags &flags) :
+		FlowController(Memory &memory, Registers &registers, Segments &segments, Flags &flags) :
-			memory_(memory), registers_(registers), flags_(flags) {}
+			memory_(memory), registers_(registers), segments_(segments), flags_(flags) {}
 
 		// Requirements for perform.
 		void jump(uint16_t address) {
@@ -349,7 +375,7 @@ class FlowController {
 
 		void jump(uint16_t segment, uint16_t address) {
 			registers_.cs_ = segment;
-			registers_.did_update(Registers::Source::CS);
+			segments_.did_update(Segments::Source::CS);
 			registers_.ip_ = address;
 		}
 
@@ -371,6 +397,7 @@ class FlowController {
 	private:
 		Memory &memory_;
 		Registers &registers_;
+		Segments &segments_;
 		Flags &flags_;
 		bool should_repeat_ = false;
 };
@@ -378,12 +405,16 @@ class FlowController {
 struct ExecutionSupport {
 	Flags flags;
 	Registers registers;
+	Segments segments;
 	Memory memory;
 	FlowController flow_controller;
 	IO io;
 	static constexpr auto model = InstructionSet::x86::Model::i8086;
 
-	ExecutionSupport(): memory(registers), flow_controller(memory, registers, flags) {}
+	ExecutionSupport():
+		memory(registers, segments),
+		segments(registers),
+		flow_controller(memory, registers, segments, flags) {}
 
 	void clear() {
 		memory.clear();
@@ -560,11 +591,6 @@ struct FailedExecution {
 	registers.ss_ = [value[@"ss"] intValue];
 	registers.ip_ = [value[@"ip"] intValue];
 
-	registers.did_update(Registers::Source::ES);
-	registers.did_update(Registers::Source::CS);
-	registers.did_update(Registers::Source::DS);
-	registers.did_update(Registers::Source::SS);
-
 	const uint16_t flags_value = [value[@"flags"] intValue];
 	flags.set(flags_value);
 
@@ -610,6 +636,7 @@ struct FailedExecution {
 	[self populate:initial_registers flags:initial_flags value:initial_state[@"regs"]];
 	execution_support.flags = initial_flags;
 	execution_support.registers = initial_registers;
+	execution_support.segments.reset();
 
 	// Execute instruction.
 	//
@@ -657,8 +684,11 @@ struct FailedExecution {
 		break;
 	}
 
+	Segments intended_segments(intended_registers);
 	[self populate:intended_registers flags:intended_flags value:final_state[@"regs"]];
-	const bool registersEqual = intended_registers == execution_support.registers;
+	intended_segments.reset();
+
+	const bool registersEqual = intended_registers == execution_support.registers && intended_segments == execution_support.segments;
 	const bool flagsEqual = (intended_flags.get() & flags_mask) == (execution_support.flags.get() & flags_mask);
 
 	// Exit if no issues were found.
@@ -703,7 +733,6 @@ struct FailedExecution {
 			non_exception_registers.sp() = execution_support.registers.sp();
 			non_exception_registers.ax() = execution_support.registers.ax();
 			non_exception_registers.cs() = execution_support.registers.cs();
-			non_exception_registers.cs_base_ = execution_support.registers.cs_base_;
 
 			if(non_exception_registers == execution_support.registers) {
 				failure_list = &permitted_failures;