From af973138df3275f4c85ec1c52d8ad67e1a7c23cf Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 3 May 2022 15:32:54 -0400
Subject: [PATCH] Correct decoding of Bcc.b, satisfying Bcc and BSR tests.

---
 InstructionSets/M68k/Decoder.cpp                       |  7 ++++++-
 InstructionSets/M68k/Executor.hpp                      |  1 +
 .../M68k/Implementation/ExecutorImplementation.hpp     |  7 +++++++
 .../M68k/Implementation/PerformImplementation.hpp      | 10 ++++++++++
 InstructionSets/M68k/Instruction.hpp                   |  1 +
 .../Mac/Clock SignalTests/68000ComparativeTests.mm     |  5 +++--
 6 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/InstructionSets/M68k/Decoder.cpp b/InstructionSets/M68k/Decoder.cpp
index edfc86ec8..45e3e5c31 100644
--- a/InstructionSets/M68k/Decoder.cpp
+++ b/InstructionSets/M68k/Decoder.cpp
@@ -812,10 +812,15 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
 		// No further operands decoded, but note that one is somewhere in the opcode.
 		//
 		case OpT(Operation::TRAP):
-		case OpT(Operation::Bccb):
 		case OpT(Operation::BSRb):
 			return validated<op, validate>(AddressingMode::Quick);
 
+		case OpT(Operation::Bccb):
+			return validated<op, validate>(
+				AddressingMode::Quick, 0,
+				AddressingMode::None, 0,
+				Condition((instruction >> 8) & 0xf));
+
 		//
 		// MARK: LINKw
 		//
diff --git a/InstructionSets/M68k/Executor.hpp b/InstructionSets/M68k/Executor.hpp
index 917f44114..b2abd9c61 100644
--- a/InstructionSets/M68k/Executor.hpp
+++ b/InstructionSets/M68k/Executor.hpp
@@ -45,6 +45,7 @@ template <Model model, typename BusHandler> class Executor {
 		void add_pc(uint32_t);
 		void decline_branch() {}
 		void did_update_status();
+		void bsr(uint32_t offset);
 
 		// 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 cf541a5e5..683512f91 100644
--- a/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
+++ b/InstructionSets/M68k/Implementation/ExecutorImplementation.hpp
@@ -364,6 +364,13 @@ void Executor<model, BusHandler>::add_pc(uint32_t offset) {
 	program_counter_.l = instruction_address_ + offset;
 }
 
+template <Model model, typename BusHandler>
+void Executor<model, BusHandler>::bsr(uint32_t offset) {
+	address_[7].l -= 4;
+	bus_handler_.template write<uint32_t>(address_[7].l, program_counter_.l);
+	program_counter_.l = instruction_address_ + offset;
+}
+
 }
 }
 
diff --git a/InstructionSets/M68k/Implementation/PerformImplementation.hpp b/InstructionSets/M68k/Implementation/PerformImplementation.hpp
index 5f8bd6af6..c72e45be8 100644
--- a/InstructionSets/M68k/Implementation/PerformImplementation.hpp
+++ b/InstructionSets/M68k/Implementation/PerformImplementation.hpp
@@ -302,6 +302,16 @@ template <
 			}
 		break;
 
+		case Operation::BSRb:
+			flow_controller.bsr(int8_t(src.b) + 2);
+		break;
+		case Operation::BSRw:
+			flow_controller.bsr(int16_t(src.w) + 2);
+		break;
+		case Operation::BSRl:
+			flow_controller.bsr(src.l + 2);
+		break;
+
 		case Operation::DBcc:
 			// Decide what sort of DBcc this is.
 			if(!status.evaluate_condition(instruction.condition())) {
diff --git a/InstructionSets/M68k/Instruction.hpp b/InstructionSets/M68k/Instruction.hpp
index 8868f01fc..51fd07fe2 100644
--- a/InstructionSets/M68k/Instruction.hpp
+++ b/InstructionSets/M68k/Instruction.hpp
@@ -273,6 +273,7 @@ template <Model model, Operation t_operation = Operation::Undefined> uint8_t ope
 		case Operation::ANDItoSR:	case Operation::ANDItoCCR:
 		case Operation::EORItoSR:	case Operation::EORItoCCR:
 		case Operation::Bccb:		case Operation::Bccw:		case Operation::Bccl:
+		case Operation::BSRb:		case Operation::BSRw:		case Operation::BSRl:
 			return FetchOp1;
 
 		//
diff --git a/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm b/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm
index 4862534d8..7d24a212e 100644
--- a/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm	
+++ b/OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm	
@@ -35,11 +35,12 @@
 //	eor_and_or
 //	addq_subq
 //	addx_subx
+//	bcc
 
 - (void)setUp {
 	// To limit tests run to a subset of files and/or of tests, uncomment and fill in below.
-	_fileSet = [NSSet setWithArray:@[@"bcc.json"]];
-//	_testSet = [NSSet setWithArray:@[@"Bcc 6000 [0]"]];
+	_fileSet = [NSSet setWithArray:@[@"btst_bchg_bclr_bset.json"]];
+//	_testSet = [NSSet setWithArray:@[@"Bcc 6206"]];
 //	_fileSet = [NSSet setWithArray:@[@"jmp_jsr.json"]];
 //	_testSet = [NSSet setWithArray:@[@"CHK 41a8"]];
 }