From d0a9b5cb81db93cb0d36710dab7d9bbdf1d52e8b Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 10 Oct 2023 22:09:10 -0400
Subject: [PATCH] Implement NEG, NOT.

---
 .../Implementation/PerformImplementation.hpp  | 36 +++++++++++++++++++
 InstructionSets/x86/Instruction.hpp           |  4 +--
 OSBindings/Mac/Clock SignalTests/8088Tests.mm | 10 ++++--
 3 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/InstructionSets/x86/Implementation/PerformImplementation.hpp b/InstructionSets/x86/Implementation/PerformImplementation.hpp
index dfee72060..55f5582b5 100644
--- a/InstructionSets/x86/Implementation/PerformImplementation.hpp
+++ b/InstructionSets/x86/Implementation/PerformImplementation.hpp
@@ -749,6 +749,40 @@ void xor_(IntT &destination, IntT source, Status &status) {
 	status.zero = status.parity = destination;
 }
 
+template <typename IntT>
+void neg(IntT &destination, Status &status) {
+	/*
+		IF DEST = 0
+			THEN CF ← 0
+			ELSE CF ← 1;
+		FI;
+		DEST ← –(DEST)
+	*/
+	/*
+		The CF flag cleared to 0 if the source operand is 0; otherwise it is set to 1.
+		The OF, SF, ZF, AF, and PF flags are set according to the result.
+	*/
+	status.auxiliary_carry = Numeric::carried_in<4>(IntT(0), destination, IntT(-destination));
+
+	destination = -destination;
+
+	status.carry = destination;
+	status.overflow = destination == top_bit<IntT>();
+	status.sign = destination & top_bit<IntT>();
+	status.zero = status.parity = destination;
+}
+
+template <typename IntT>
+void not_(IntT &destination) {
+	/*
+		DEST ← NOT DEST;
+	*/
+	/*
+		Flags affected: none.
+	*/
+	destination  = ~destination;
+}
+
 template <typename IntT, typename RegistersT, typename FlowControllerT>
 inline void call_relative(IntT offset, RegistersT &registers, FlowControllerT &flow_controller) {
 	flow_controller.call(registers.ip() + offset);
@@ -944,6 +978,8 @@ template <
 		case Operation::AND:	Primitive::and_(destination(), source(), status);		break;
 		case Operation::OR:		Primitive::or_(destination(), source(), status);		break;
 		case Operation::XOR:	Primitive::xor_(destination(), source(), status);		break;
+		case Operation::NEG:	Primitive::neg(source(), status);						break;
+		case Operation::NOT:	Primitive::not_(source());								break;
 
 		case Operation::CALLrel:
 			Primitive::call_relative(instruction.displacement(), registers, flow_controller);
diff --git a/InstructionSets/x86/Instruction.hpp b/InstructionSets/x86/Instruction.hpp
index 9bbc80dc4..3cd6f756f 100644
--- a/InstructionSets/x86/Instruction.hpp
+++ b/InstructionSets/x86/Instruction.hpp
@@ -144,9 +144,9 @@ enum class Operation: uint8_t {
 
 	/// Loads the destination with the source.
 	MOV,
-	/// Negatives; source and destination point to the same thing, to negative.
+	/// Negatives; source indicates what to negative.
 	NEG,
-	/// Logical NOT; source and destination point to the same thing, to negative.
+	/// Logical NOT; source indicates what to negative.
 	NOT,
 	/// Logical AND; source, destination, operand and displacement will be populated appropriately.
 	AND,
diff --git a/OSBindings/Mac/Clock SignalTests/8088Tests.mm b/OSBindings/Mac/Clock SignalTests/8088Tests.mm
index 6c166c4fb..a14a11adb 100644
--- a/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/8088Tests.mm	
@@ -376,12 +376,11 @@ struct FailedExecution {
 		// TODO: LOOP, LOOPE, LOOPNE
 
 		// TODO: MOV
-		// TODO: NEG, NOT
 
 		// AND
 		@"20.json.gz",	@"21.json.gz",	@"22.json.gz",	@"23.json.gz",	@"24.json.gz",	@"25.json.gz",
 		@"80.4.json.gz", @"81.4.json.gz", @"83.4.json.gz",
-*/
+
 		// OR
 		@"08.json.gz",	@"09.json.gz",	@"0A.json.gz",	@"0B.json.gz",	@"0C.json.gz",	@"0D.json.gz",
 		@"80.1.json.gz", @"81.1.json.gz", @"83.1.json.gz",
@@ -389,6 +388,13 @@ struct FailedExecution {
 		// XOR
 		@"30.json.gz",	@"31.json.gz",	@"32.json.gz",	@"33.json.gz",	@"34.json.gz",	@"35.json.gz",
 		@"80.6.json.gz", @"81.6.json.gz", @"83.6.json.gz",
+*/
+
+		// NEG
+		@"F6.3.json.gz",	@"F7.3.json.gz",
+
+		// NOT
+		@"F6.2.json.gz",	@"F7.2.json.gz",
 
 /*
 		// NOP