Implement Bcc.

OSBindings/Mac/Clock SignalTests/68000ComparativeTests.mm

@@ -156,7 +156,7 @@ struct TestProcessor: public CPU::MC68000Mk2::BusHandler {
 
 	// To limit tests run to a subset of files and/or of tests, uncomment and fill in below.
 	_fileSet = [NSSet setWithArray:@[
-//		@"bcc.json",
+		@"bcc.json",
 
 		// Below this line are passing tests.
 		@"abcd_sbcd.json",
@@ -167,7 +167,7 @@ struct TestProcessor: public CPU::MC68000Mk2::BusHandler {
 		@"dbcc_scc.json",
 		@"eor_and_or.json",
 		@"nbcd.json",
-		@"ext.json"]];
+		@"ext.json"]];		// 9/32 = ~28% done, as far as the tests go.
 //	_testSet = [NSSet setWithArray:@[@"ADDQ 05df"]];
 }
 

Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp

@@ -91,6 +91,11 @@ enum ExecutionState: int {
 	DBcc_branch_taken,
 	DBcc_condition_true,
 	DBcc_counter_overflow,
+
+	Bcc,
+	Bcc_branch_taken,
+	Bcc_b_branch_not_taken,
+	Bcc_w_branch_not_taken,
 };
 
 // MARK: - The state machine.
@@ -523,6 +528,9 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 				StdCASE(DBcc,	perform_state_ = DBcc);
 
+				StdCASE(Bccb,	perform_state_ = Bcc);
+				StdCASE(Bccw,	perform_state_ = Bcc);
+
 				default:
 					assert(false);
 			}
@@ -962,7 +970,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 
 
 		//
-		// Specific forms of perform.
+		// Specific forms of perform...
 		//
 
 		BeginState(MOVEw):
@@ -988,6 +996,9 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			Prefetch()		// np
 		MoveToState(Decode);
 
+		//
+		// [ABCD/SBCD/SUBX/ADDX] (An)-, (An)-
+		//
 		BeginState(TwoOp_Predec_bw):
 			IdleBus(1);					// n
 
@@ -1046,7 +1057,6 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 		//
 		// CHK
 		//
-
 		BeginState(CHK):
 			Prefetch();			// np
 			InstructionSet::M68k::perform<
@@ -1079,7 +1089,6 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 		//
 		// Scc
 		//
-
 		BeginState(Scc_Dn):
 			Prefetch();			// np
 			InstructionSet::M68k::perform<
@@ -1113,7 +1122,7 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			// Just do the write-back here.
 			registers_[instruction_.reg(0)].w = operand_[0].w;
 
-			// Next state was set by complete_dbcc. Branch to it.
+			// Next state was set by complete_dbcc.
 		break;
 
 		BeginState(DBcc_branch_taken):
@@ -1141,6 +1150,33 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
 			Prefetch();		// np
 		MoveToState(Decode);
 
+		//
+		// Bcc [.b and .w]
+		//
+		BeginState(Bcc):
+			InstructionSet::M68k::perform<InstructionSet::M68k::Model::M68000>(
+				instruction_, operand_[0], operand_[1], status_, *static_cast<ProcessorBase *>(this));
+
+			// Next state was set by complete_bcc.
+		break;
+
+		BeginState(Bcc_branch_taken):
+			IdleBus(1);		// n
+			Prefetch();		// np
+			Prefetch();		// np
+		MoveToState(Decode);
+
+		BeginState(Bcc_b_branch_not_taken):
+			IdleBus(2);		// nn
+			Prefetch();		// np
+		MoveToState(Decode);
+
+		BeginState(Bcc_w_branch_not_taken):
+			IdleBus(2);		// nn
+			Prefetch();		// np
+			Prefetch();		// np
+		MoveToState(Decode);
+
 		//
 		// Various states TODO.
 		//
@@ -1207,6 +1243,18 @@ void ProcessorBase::complete_dbcc(bool matched_condition, bool overflowed, int16
 	state_ = DBcc_condition_true;
 }
 
+template <typename IntT> void ProcessorBase::complete_bcc(bool take_branch, IntT offset) {
+	if(take_branch) {
+		program_counter_.l = instruction_address_.l + uint32_t(offset) + 2;
+		state_ = Bcc_branch_taken;
+		return;
+	}
+
+	state_ =
+		(instruction_.operation == InstructionSet::M68k::Operation::Bccb) ?
+			Bcc_b_branch_not_taken : Bcc_w_branch_not_taken;
+}
+
 // MARK: - External state.
 
 template <class BusHandler, bool dtack_is_implicit, bool permit_overrun, bool signal_will_perform>

Processors/68000Mk2/Implementation/68000Mk2Storage.hpp

@@ -108,7 +108,7 @@ struct ProcessorBase: public InstructionSet::M68k::NullFlowController {
 	template <bool did_overflow> void did_divs(int32_t, int32_t) {}
 	inline void did_bit_op(int) {}
 	inline void did_update_status();
-	template <typename IntT> void complete_bcc(bool, IntT) {}
+	template <typename IntT> void complete_bcc(bool, IntT);
 	inline void complete_dbcc(bool, bool, int16_t);
 	inline void bsr(uint32_t) {}
 	inline void jsr(uint32_t) {}