From 1defeca1ade29d13915d772ff6bda4bc73ad0042 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Fri, 6 May 2022 12:30:49 -0400
Subject: [PATCH] Implement RTS, RTR, RTE.

---
 InstructionSets/M68k/Executor.hpp             |  3 +++
 .../Implementation/ExecutorImplementation.hpp | 20 ++++++++++++++++
 .../Implementation/PerformImplementation.hpp  | 24 ++++++++-----------
 InstructionSets/M68k/Instruction.hpp          |  1 +
 .../68000ComparativeTests.mm                  |  4 +++-
 5 files changed, 37 insertions(+), 15 deletions(-)

diff --git a/InstructionSets/M68k/Executor.hpp b/InstructionSets/M68k/Executor.hpp
index c77ddecaf..6c35cde9b 100644
--- a/InstructionSets/M68k/Executor.hpp
+++ b/InstructionSets/M68k/Executor.hpp
@@ -55,6 +55,9 @@ template <Model model, typename BusHandler> class Executor {
 		template <typename IntT> void movem_toR(Preinstruction instruction, uint32_t source, uint32_t dest);
 		void pea(uint32_t address);
 		void tas(Preinstruction instruction, uint32_t address);
+		void rtr();
+		void rts();
+		void rte();
 
 		// TODO: ownership of this shouldn't be here.
 		struct Registers {
diff --git a/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp b/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
index 96ee3ba00..5b232e632 100644
--- a/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
+++ b/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
@@ -401,6 +401,26 @@ void Executor<model, BusHandler>::pea(uint32_t address) {
 	bus_handler_.template write<uint32_t>(sp().l, address);
 }
 
+template <Model model, typename BusHandler>
+void Executor<model, BusHandler>::rtr() {
+	status_.set_ccr(bus_handler_.template read<uint16_t>(sp().l));
+	sp().l += 2;
+	rts();
+}
+
+template <Model model, typename BusHandler>
+void Executor<model, BusHandler>::rte() {
+	status_.set_status(bus_handler_.template read<uint16_t>(sp().l));
+	sp().l += 2;
+	rts();
+}
+
+template <Model model, typename BusHandler>
+void Executor<model, BusHandler>::rts() {
+	program_counter_.l = bus_handler_.template read<uint32_t>(sp().l);
+	sp().l += 4;
+}
+
 template <Model model, typename BusHandler>
 void Executor<model, BusHandler>::tas(Preinstruction instruction, uint32_t address) {
 	uint8_t original_value;
diff --git a/InstructionSets/M68k/Implementation/PerformImplementation.hpp b/InstructionSets/M68k/Implementation/PerformImplementation.hpp
index b227d264f..2f98a4b4a 100644
--- a/InstructionSets/M68k/Implementation/PerformImplementation.hpp
+++ b/InstructionSets/M68k/Implementation/PerformImplementation.hpp
@@ -1204,21 +1204,17 @@ template <
 		/*
 			RTE and RTR share an implementation.
 		*/
-//		case Operation::RTE_RTR:
-//			// If this is RTR, patch out the supervisor half of the status register.
-//			if(decoded_instruction_.l == 0x4e77) {
-//				const auto current_status = status();
-//				source_bus_data_.halves.low.halves.high =
-//					uint8_t(current_status >> 8);
-//			}
-//			apply_status(source_bus_data_.l);
-//		break;
+		case Operation::RTR:
+			flow_controller.rtr();
+		break;
 
-//		case Operation::RTE:
-//		break;
-//
-//		case Operation::RTR:
-//		break;
+		case Operation::RTE:
+			flow_controller.rte();
+		break;
+
+		case Operation::RTS:
+			flow_controller.rts();
+		break;
 
 		/*
 			TSTs: compare to zero.
diff --git a/InstructionSets/M68k/Instruction.hpp b/InstructionSets/M68k/Instruction.hpp
index d04dc373d..b189259a9 100644
--- a/InstructionSets/M68k/Instruction.hpp
+++ b/InstructionSets/M68k/Instruction.hpp
@@ -276,6 +276,7 @@ template <Model model, Operation t_operation = Operation::Undefined> uint8_t ope
 		case Operation::MOVEMtoMw:	case Operation::MOVEMtoMl:
 		case Operation::MOVEMtoRw:	case Operation::MOVEMtoRl:
 		case Operation::TAS:
+		case Operation::RTR:		case Operation::RTS:		case Operation::RTE:
 			return 0;
 
 		//
diff --git a/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm b/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm
index 8064e14b3..bb54dd6e5 100644
--- a/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm	
@@ -52,6 +52,8 @@
 //	swap
 //	tas
 //	tst
+//	rts
+//	rtr
 
 // Issues to fix:
 //
@@ -81,7 +83,7 @@
 
 - (void)setUp {
 	// To limit tests run to a subset of files and/or of tests, uncomment and fill in below.
-	_fileSet = [NSSet setWithArray:@[@"rts.json", @"rtr.json"]];
+//	_fileSet = [NSSet setWithArray:@[@"rts.json", @"rtr.json"]];
 //	_testSet = [NSSet setWithArray:@[@"NEGX 00c0"]];
 //	_fileSet = [NSSet setWithArray:@[@"jmp_jsr.json"]];
 //	_testSet = [NSSet setWithArray:@[@"CHK 41a8"]];