diff --git a/InstructionSets/68k/Decoder.cpp b/InstructionSets/68k/Decoder.cpp
index 2d8680fb4..9db1367c8 100644
--- a/InstructionSets/68k/Decoder.cpp
+++ b/InstructionSets/68k/Decoder.cpp
@@ -91,6 +91,11 @@ constexpr Operation Predecoder<model>::operation(OpT op) {
return Operation::Undefined;
}
+template <Model model>
+template <uint8_t operation, bool validate> Preinstruction Predecoder<model>::validated(Preinstruction original) {
+ return original;
+}
+
/// Decodes the fields within an instruction and constructs a `Preinstruction`, given that the operation has already been
/// decoded. Optionally applies validation
template <Model model>
@@ -119,9 +124,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
const auto addressing_mode = (instruction & 8) ?
AddressingMode::AddressRegisterIndirectWithPredecrement : AddressingMode::DataRegisterDirect;
- return Preinstruction(operation,
- addressing_mode, ea_register,
- addressing_mode, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ addressing_mode, ea_register,
+ addressing_mode, data_register));
}
//
@@ -169,9 +175,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// }
// }
- return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, data_register,
- ea_combined_mode, ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, data_register,
+ ea_combined_mode, ea_register));
} else {
// < ea > Λ Dn → Dn
@@ -180,9 +187,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// return Preinstruction();
// }
- return Preinstruction(operation,
- ea_combined_mode, ea_register,
- AddressingMode::DataRegisterDirect, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ ea_combined_mode, ea_register,
+ AddressingMode::DataRegisterDirect, data_register));
}
return Preinstruction();
@@ -202,9 +210,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case CMPIb: case CMPIl: case CMPIw:
case BTSTI: case BCHGI:
case BCLRI: case BSETI:
- return Preinstruction(operation,
- AddressingMode::ImmediateData, 0,
- combined_mode(ea_mode, ea_register), ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::ImmediateData, 0,
+ combined_mode(ea_mode, ea_register), ea_register));
//
@@ -215,9 +224,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
//
case OpT(Operation::BTST): case OpT(Operation::BCLR):
case OpT(Operation::BCHG): case OpT(Operation::BSET):
- return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, data_register,
- combined_mode(ea_mode, ea_register), ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, data_register,
+ combined_mode(ea_mode, ea_register), ea_register));
//
// MARK: STOP, ANDItoCCR, ANDItoSR, EORItoCCR, EORItoSR, ORItoCCR, ORItoSR, Bccl, Bccw, BSRl, BSRw
@@ -230,9 +240,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case OpT(Operation::ORItoSR): case OpT(Operation::ORItoCCR):
case OpT(Operation::ANDItoSR): case OpT(Operation::ANDItoCCR):
case OpT(Operation::EORItoSR): case OpT(Operation::EORItoCCR):
- return Preinstruction(operation,
- AddressingMode::ImmediateData, 0,
- operation == Operation::ORItoSR || operation == Operation::ANDItoSR || operation == Operation::EORItoSR);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::ImmediateData, 0,
+ operation == Operation::ORItoSR || operation == Operation::ANDItoSR || operation == Operation::EORItoSR));
//
// MARK: CHK
@@ -241,9 +252,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// b0–b2 and b3–b5: source effective address.
//
case OpT(Operation::CHK):
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register,
- AddressingMode::DataRegisterDirect, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register,
+ AddressingMode::DataRegisterDirect, data_register));
//
// MARK: EXG.
@@ -256,17 +268,20 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
switch((instruction >> 3)&31) {
default: return Preinstruction();
- case 0x08: return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, ea_register,
- AddressingMode::DataRegisterDirect, data_register);
+ case 0x08: return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, ea_register,
+ AddressingMode::DataRegisterDirect, data_register));
- case 0x09: return Preinstruction(operation,
- AddressingMode::AddressRegisterDirect, ea_register,
- AddressingMode::AddressRegisterDirect, data_register);
+ case 0x09: return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::AddressRegisterDirect, ea_register,
+ AddressingMode::AddressRegisterDirect, data_register));
- case 0x11: return Preinstruction(operation,
- AddressingMode::AddressRegisterDirect, ea_register,
- AddressingMode::DataRegisterDirect, data_register);
+ case 0x11: return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::AddressRegisterDirect, ea_register,
+ AddressingMode::DataRegisterDirect, data_register));
}
//
@@ -277,9 +292,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
//
case OpT(Operation::DIVU): case OpT(Operation::DIVS):
case OpT(Operation::MULU): case OpT(Operation::MULS):
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register,
- AddressingMode::DataRegisterDirect, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register,
+ AddressingMode::DataRegisterDirect, data_register));
//
// MARK: LEA
@@ -288,9 +304,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// b0–b2 and b3–b5: source effective address.
//
case LEA:
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register,
- AddressingMode::AddressRegisterDirect, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register,
+ AddressingMode::AddressRegisterDirect, data_register));
//
// MARK: MOVEPtoRw, MOVEPtoRl
@@ -300,14 +317,16 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// [already decoded: b6–b8: an opmode, indicating size and direction]
//
case OpT(MOVEPtoRw): case OpT(MOVEPtoRl):
- return Preinstruction(operation,
- AddressingMode::AddressRegisterIndirectWithDisplacement, ea_register,
- AddressingMode::DataRegisterDirect, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::AddressRegisterIndirectWithDisplacement, ea_register,
+ AddressingMode::DataRegisterDirect, data_register));
case OpT(MOVEPtoMw): case OpT(MOVEPtoMl):
- return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, data_register,
- AddressingMode::AddressRegisterIndirectWithDisplacement, ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, data_register,
+ AddressingMode::AddressRegisterIndirectWithDisplacement, ea_register));
//
// MARK: MOVE
@@ -317,9 +336,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// [already decoded: b12–b13: size]
//
case OpT(Operation::MOVEb): case OpT(Operation::MOVEl): case OpT(Operation::MOVEw):
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register,
- combined_mode<false, false>(opmode, data_register), data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register,
+ combined_mode<false, false>(opmode, data_register), data_register));
//
// MARK: RESET, NOP RTE, RTS, TRAPV, RTR
@@ -329,7 +349,7 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case OpT(Operation::RESET): case OpT(Operation::NOP):
case OpT(Operation::RTE): case OpT(Operation::RTS): case OpT(Operation::TRAPV):
case OpT(Operation::RTR):
- return Preinstruction(operation);
+ return validated<op, validate>(Preinstruction(operation));
//
// MARK: NEGX, CLR, NEG, MOVEtoCCR, MOVEtoSR, NOT, NBCD, PEA, TST
@@ -347,8 +367,9 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case OpT(Operation::TAS):
case OpT(Operation::TSTb): case OpT(Operation::TSTw): case OpT(Operation::TSTl):
case OpT(Operation::Scc):
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register));
//
// MARK: UNLINK, MOVEtoUSP, MOVEfromUSP
@@ -357,8 +378,9 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
//
case OpT(Operation::UNLINK):
case OpT(Operation::MOVEfromUSP): case OpT(Operation::MOVEtoUSP):
- return Preinstruction(operation,
- AddressingMode::AddressRegisterDirect, ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::AddressRegisterDirect, ea_register));
//
// MARK: DBcc
@@ -367,9 +389,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// Followed by an immediate value.
//
case OpT(Operation::DBcc):
- return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, ea_register,
- AddressingMode::ImmediateData, 0);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, ea_register,
+ AddressingMode::ImmediateData, 0));
//
// MARK: SWAP, EXTbtow, EXTwtol
@@ -378,8 +401,9 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
//
case OpT(Operation::SWAP):
case OpT(Operation::EXTbtow): case OpT(Operation::EXTwtol):
- return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, ea_register));
//
// MARK: MOVEMtoMw, MOVEMtoMl, MOVEMtoRw, MOVEMtoRl
@@ -388,16 +412,16 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// [already decoded: b10: direction]
//
case MOVEMtoMl: case MOVEMtoMw:
- return Preinstruction(operation,
- AddressingMode::ImmediateData, 0,
- combined_mode(ea_mode, ea_register), ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::ImmediateData, 0,
+ combined_mode(ea_mode, ea_register), ea_register));
case MOVEMtoRl: case MOVEMtoRw:
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register,
- AddressingMode::ImmediateData, 0);
-
- // TODO: more validation on the above.
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register,
+ AddressingMode::ImmediateData, 0));
//
// MARK: TRAP, BCCb, BSRb
@@ -407,8 +431,9 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case OpT(Operation::TRAP):
case OpT(Operation::Bccb):
case OpT(Operation::BSRb):
- return Preinstruction(operation,
- AddressingMode::Quick, 0);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::Quick, 0));
//
// MARK: LINKw
@@ -417,9 +442,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
// Implicitly: 'destination' is an immediate.
//
case OpT(Operation::LINKw):
- return Preinstruction(operation,
- AddressingMode::AddressRegisterDirect, ea_register,
- AddressingMode::ImmediateData, 0);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::AddressRegisterDirect, ea_register,
+ AddressingMode::ImmediateData, 0));
//
// MARK: ADDQ, SUBQ
@@ -429,9 +455,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
//
case ADDQb: case ADDQw: case ADDQl:
case SUBQb: case SUBQw: case SUBQl:
- return Preinstruction(operation,
- AddressingMode::Quick, 0,
- combined_mode(ea_mode, ea_register), ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::Quick, 0,
+ combined_mode(ea_mode, ea_register), ea_register));
//
// MARK: MOVEq
@@ -441,9 +468,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
//
// TODO: does this need to be a separate instruction from MOVEl?
case OpT(Operation::MOVEq):
- return Preinstruction(operation,
- AddressingMode::Quick, 0,
- AddressingMode::DataRegisterDirect, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::Quick, 0,
+ AddressingMode::DataRegisterDirect, data_register));
//
// MARK: ASR, LSR, ROXR, ROR, ASL, LSL, ROXL, ROL
@@ -459,9 +487,10 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case OpT(Operation::LSLb): case OpT(Operation::LSLw): case OpT(Operation::LSLl):
case OpT(Operation::ROXLb): case OpT(Operation::ROXLw): case OpT(Operation::ROXLl):
case OpT(Operation::ROLb): case OpT(Operation::ROLw): case OpT(Operation::ROLl):
- return Preinstruction(operation,
- AddressingMode::DataRegisterDirect, ea_register,
- (instruction & 0x100) ? AddressingMode::DataRegisterDirect : AddressingMode::Quick, data_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ AddressingMode::DataRegisterDirect, ea_register,
+ (instruction & 0x100) ? AddressingMode::DataRegisterDirect : AddressingMode::Quick, data_register));
//
// MARK: ASRm, LSRm, ROXRm, RORm, ASLm, LSLm, ROXLm, ROLm
@@ -472,8 +501,9 @@ template <uint8_t op, bool validate> Preinstruction Predecoder<model>::decode(ui
case OpT(Operation::LSRm): case OpT(Operation::LSLm):
case OpT(Operation::ROXRm): case OpT(Operation::ROXLm):
case OpT(Operation::RORm): case OpT(Operation::ROLm):
- return Preinstruction(operation,
- combined_mode(ea_mode, ea_register), ea_register);
+ return validated<op, validate>(
+ Preinstruction(operation,
+ combined_mode(ea_mode, ea_register), ea_register));
//
// MARK: Impossible error case.
diff --git a/InstructionSets/68k/Decoder.hpp b/InstructionSets/68k/Decoder.hpp
index b023c938e..3812f7740 100644
--- a/InstructionSets/68k/Decoder.hpp
+++ b/InstructionSets/68k/Decoder.hpp
@@ -48,6 +48,7 @@ template <Model model> class Predecoder {
// Specific instruction decoders.
template <OpT operation, bool validate = true> Preinstruction decode(uint16_t instruction);
+ template <OpT operation, bool validate> Preinstruction validated(Preinstruction original);
// Extended operation list; collapses into a single byte enough information to
// know both the type of operation and how to decode the operands. Most of the