Add 'quick' decoding and testing.

InstructionSets/68k/Decoder.cpp

@@ -172,14 +172,20 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::validated
 
 		// ADD, SUB, MOVE, MOVEA
 		case OpT(Operation::ADDb):		case OpT(Operation::ADDw):	case OpT(Operation::ADDl):
+		case ADDQb:						case ADDQw:					case ADDQl:
 		case OpT(Operation::SUBb):		case OpT(Operation::SUBw):	case OpT(Operation::SUBl):
+		case SUBQb:						case SUBQw:					case SUBQl:
 		case OpT(Operation::MOVEb):		case OpT(Operation::MOVEw):	case OpT(Operation::MOVEl):
-		case OpT(Operation::MOVEAw):	case OpT(Operation::MOVEAl):
+		case OpT(Operation::MOVEAw):	case OpT(Operation::MOVEAl): {
+			// TODO: I'm going to need get-size-by-operation elsewhere; use that here when implemented.
+			constexpr bool is_byte =
+				op == OpT(Operation::ADDb) || op == OpT(Operation::SUBb) || op == OpT(Operation::MOVEb) ||
+				op == ADDQb	|| op == SUBQb;
+
 			switch(original.mode<0>()) {
 				default: break;
 				case AddressingMode::AddressRegisterDirect:
-					// TODO: I'm going to need get-size-by-operation elsewhere; use that here when implemented.
+					if constexpr (!is_byte) {
-					if constexpr (op != OpT(Operation::ADDb) && op != OpT(Operation::SUBb) && op != OpT(Operation::MOVEb)) {
 						break;
 					}
 					[[fallthrough]];
@@ -191,7 +197,7 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::validated
 				default: return original;
 
 				case AddressingMode::AddressRegisterDirect:
-					if constexpr (op == OpT(Operation::MOVEAw) || op == OpT(Operation::MOVEAl)) {
+					if constexpr (!is_byte) {
 						return original;
 					}
 					[[fallthrough]];
@@ -201,6 +207,7 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::validated
 				case AddressingMode::None:
 					return Preinstruction();
 			}
+		}
 
 		// ADDA, SUBA.
 		case OpT(Operation::ADDAw):	case OpT(Operation::ADDAl):
@@ -1061,7 +1068,11 @@ Preinstruction Predecoder<model>::decode7(uint16_t instruction) {
 	using Op = Operation;
 
 	// 4-134 (p238)
-	Decode(Op::MOVEq);
+	if(!(instruction & 0x100)) {
+		Decode(Op::MOVEq);
+	} else {
+		return Preinstruction();
+	}
 }
 
 template <Model model>

InstructionSets/68k/Instruction.hpp

@@ -136,6 +136,28 @@ constexpr int size(Operation operation) {
 	}
 }
 
+template <Operation op>
+constexpr int8_t quick(uint16_t instruction) {
+	switch(op) {
+		case Operation::Bccb:
+		case Operation::MOVEq:	return int8_t(instruction);
+		default: {
+			int8_t value = (instruction >> 9) & 7;
+			value |= (value - 1)&8;
+			return value;
+		}
+	}
+}
+
+constexpr int8_t quick(Operation op, uint16_t instruction) {
+	if(op == Operation::MOVEq || op == Operation::Bccb) {
+		return quick<Operation::MOVEq>(instruction);
+	} else {
+		// ADDw is arbitrary; anything other than MOVEq will do.
+		return quick<Operation::ADDw>(instruction);
+	}
+}
+
 /// Indicates the addressing mode applicable to an operand.
 ///
 /// Implementation notes:

OSBindings/Mac/Clock SignalTests/m68kDecoderTests.mm

@@ -17,7 +17,7 @@ using namespace InstructionSet::M68k;
 
 namespace {
 
-template <int index> NSString *operand(Preinstruction instruction) {
+template <int index> NSString *operand(Preinstruction instruction, uint16_t opcode) {
 	switch(instruction.mode<index>()) {
 		default:	return [NSString stringWithFormat:@"[Mode %d?]", int(instruction.mode<index>())];
 
@@ -52,6 +52,9 @@ template <int index> NSString *operand(Preinstruction instruction) {
 
 		case AddressingMode::ImmediateData:
 			return @"#";
+
+		case AddressingMode::Quick:
+			return [NSString stringWithFormat:@"%d", quick(instruction.operation, opcode)];
 	}
 }
 
@@ -216,10 +219,12 @@ template <int index> NSString *operand(Preinstruction instruction) {
 			case Operation::ROXRl:	instruction = @"ROXR.l";	break;
 			case Operation::ROXRm:	instruction = @"ROXR.w";	break;
 
+//			case Operation::MOVEMl:	instruction = @"MOVEM.l";	break;
+//			case Operation::MOVEMw:	instruction = @"MOVEM.w";	break;
+
 			/*
 				TODO:
 
-				MOVEMl, MOVEMw,
 				MOVEPl, MOVEPw,
 
 				ANDb,	ANDw,	ANDl,
@@ -252,17 +257,17 @@ template <int index> NSString *operand(Preinstruction instruction) {
 			continue;
 		}
 
-		NSString *const operand1 = operand<0>(found);
+		NSString *const operand1 = operand<0>(found, uint16_t(instr));
-		NSString *const operand2 = operand<1>(found);
+		NSString *const operand2 = operand<1>(found, uint16_t(instr));
 
 		if(operand1.length) instruction = [instruction stringByAppendingFormat:@" %@", operand1];
 		if(operand2.length) instruction = [instruction stringByAppendingFormat:@", %@", operand2];
 
 		// Quick decoding not yet supported. TODO.
-		if(found.mode<0>() == AddressingMode::Quick || found.mode<1>() == AddressingMode::Quick) {
+//		if(found.mode<0>() == AddressingMode::Quick || found.mode<1>() == AddressingMode::Quick) {
-			++skipped;
+//			++skipped;
-			continue;
+//			continue;
-		}
+//		}
 
 		XCTAssertFalse(found.mode<0>() == AddressingMode::None && found.mode<1>() != AddressingMode::None, @"Decoding of %@ provided a second operand but not a first", instrName);
 		XCTAssertEqualObjects(instruction, expected, "%@ should decode as %@; got %@", instrName, expected, instruction);