From cf846f501a310769961050584c795f1db569c0e1 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Thu, 12 Oct 2023 14:24:28 -0400
Subject: [PATCH] Implement LDS, LES.

---
 .../Implementation/PerformImplementation.hpp  | 47 +++++++++++++++++--
 OSBindings/Mac/Clock SignalTests/8088Tests.mm |  6 ++-
 2 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/InstructionSets/x86/Implementation/PerformImplementation.hpp b/InstructionSets/x86/Implementation/PerformImplementation.hpp
index 88e35246a..691a13b83 100644
--- a/InstructionSets/x86/Implementation/PerformImplementation.hpp
+++ b/InstructionSets/x86/Implementation/PerformImplementation.hpp
@@ -55,6 +55,21 @@ uint32_t address(
 	return address + *resolve<model, uint16_t>(instruction, pointer.base(), pointer, registers, memory);
 }
 
+template <Model model, typename IntT, typename InstructionT, typename RegistersT, typename MemoryT>
+uint32_t address(
+	InstructionT &instruction,
+	DataPointer pointer,
+	RegistersT &registers,
+	MemoryT &memory
+) {
+	switch(pointer.source<false>()) {
+		default:						return 0;
+		case Source::Indirect:			return address<model, Source::Indirect, IntT>(instruction, pointer, registers, memory);
+		case Source::IndirectNoBase:	return address<model, Source::IndirectNoBase, IntT>(instruction, pointer, registers, memory);
+		case Source::DirectAddress:		return address<model, Source::DirectAddress, IntT>(instruction, pointer, registers, memory);
+	}
+}
+
 template <Model model, typename IntT, typename InstructionT, typename RegistersT, typename MemoryT>
 IntT *resolve(
 	InstructionT &instruction,
@@ -750,11 +765,11 @@ template <Model model, typename InstructionT, typename FlowControllerT, typename
 void call_far(InstructionT &instruction,
 	FlowControllerT &flow_controller,
 	RegistersT &registers,
-	MemoryT &memory) {
-
+	MemoryT &memory
+) {
 	// TODO: eliminate 16-bit assumption below.
 	uint16_t source_address = 0;
-	auto pointer = instruction.destination();
+	const auto pointer = instruction.destination();
 	switch(pointer.template source<false>()) {
 		default:
 		case Source::Immediate:	flow_controller.call(instruction.segment(), instruction.offset());	return;
@@ -778,6 +793,25 @@ void call_far(InstructionT &instruction,
 	flow_controller.call(segment, offset);
 }
 
+template <Model model, Source selector, typename InstructionT, typename MemoryT, typename RegistersT>
+void ld(
+	InstructionT &instruction,
+	uint16_t &destination,
+	MemoryT &memory,
+	RegistersT &registers
+) {
+	const auto pointer = instruction.source();
+	auto source_address = address<model, uint16_t>(instruction, pointer, registers, memory);
+	const Source source_segment = pointer.segment(instruction.segment_override());
+
+	destination = memory.template access<uint16_t>(source_segment, source_address);
+	source_address += 2;
+	switch(selector) {
+		case Source::DS:	registers.ds() = memory.template access<uint16_t>(source_segment, source_address);	break;
+		case Source::ES:	registers.es() = memory.template access<uint16_t>(source_segment, source_address);	break;
+	}
+}
+
 template <typename FlowControllerT>
 void int_(uint8_t vector, FlowControllerT &flow_controller) {
 	flow_controller.interrupt(vector);
@@ -966,8 +1000,11 @@ template <
 		case Operation::INT:	Primitive::int_(instruction.operand(), flow_controller);	return;
 		case Operation::INTO:	Primitive::into(status, flow_controller);					return;
 
-		case Operation::SAHF:	Primitive::sahf(registers.ah(), status);					return;
-		case Operation::LAHF:	Primitive::lahf(registers.ah(), status);					return;
+		case Operation::SAHF:	Primitive::sahf(registers.ah(), status);			return;
+		case Operation::LAHF:	Primitive::lahf(registers.ah(), status);			return;
+
+		case Operation::LDS:	if constexpr (data_size == DataSize::Word) Primitive::ld<model, Source::DS>(instruction, destination(), memory, registers);	return;
+		case Operation::LES:	if constexpr (data_size == DataSize::Word) Primitive::ld<model, Source::ES>(instruction, destination(), memory, registers);	return;
 
 		case Operation::JO:		jcc(status.condition<Condition::Overflow>());		return;
 		case Operation::JNO:	jcc(!status.condition<Condition::Overflow>());		return;
diff --git a/OSBindings/Mac/Clock SignalTests/8088Tests.mm b/OSBindings/Mac/Clock SignalTests/8088Tests.mm
index ed157cf01..81a260344 100644
--- a/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
@@ -371,11 +371,13 @@ struct FailedExecution {
 
 		// INT, INT3
 		@"CC.json.gz", @"CD.json.gz",
-*/
+
 		@"9E.json.gz",	// SAHF
 		@"9F.json.gz",	// LAHF
+*/
+		@"C5.json.gz",	// LDS
+		@"C4.json.gz",	// LES
 
-		// TODO: LDS, LES
 		// TODO: LEA
 
 		// TODO: CMPS, LODS, MOVS, SCAS, STOS