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Simplify address handling; add perform patterns for CMP, AND, OR, EOR.

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This commit is contained in:
Thomas Harte 2022-05-19 12:18:47 -04:00
parent 274902c3c1
commit 084d6ca11d
1 changed files with 90 additions and 32 deletions
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104
Processors/68000Mk2/Implementation/68000Mk2Implementation.hpp
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@ -61,6 +61,7 @@ enum ExecutionState: int {
Perform_np,
Perform_np_n,
Perform_np_nn,
// MOVE has unique bus usage, so has specialised states.
@ -165,12 +166,15 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
WaitForDTACK(announce); \
CompleteAccess(perform);
// Sets up the next data access — its address and size/read flags.
#define SetupDataAccess(addr, read_flag, select_flag) \
access.address = access_announce.address = &addr; \
// Sets up the next data access size and read flags.
#define SetupDataAccess(read_flag, select_flag) \
access_announce.operation = Microcycle::NewAddress | Microcycle::IsData | (read_flag); \
access.operation = access_announce.operation | (select_flag);
// Sets the address source for the next data access.
#define SetDataAddress(addr) \
access.address = access_announce.address = &addr;
// Performs the access established by SetupDataAccess into val.
#define Access(val) \
AccessPair(val, access_announce, access)
@ -214,7 +218,8 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
status_.trace_flag = 0;
did_update_status();
SetupDataAccess(temporary_address_, Microcycle::Read, Microcycle::SelectWord);
SetupDataAccess(Microcycle::Read, Microcycle::SelectWord);
SetDataAddress(temporary_address_);
temporary_address_ = 0;
Access(registers_[15].high); // nF
@ -253,39 +258,85 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
next_operand_ = 0;
// Obtain operand flags and pick a perform pattern.
#define CASE(x) \
#define CASE(x, y) \
case InstructionSet::M68k::Operation::x: \
operand_flags_ = InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::x>();
#define FetchOperands(x) \
operand_flags_ = InstructionSet::M68k::operand_flags<InstructionSet::M68k::Model::M68000, InstructionSet::M68k::Operation::x>(); \
y; \
\
if constexpr (InstructionSet::M68k::operand_size<InstructionSet::M68k::Operation::x>() == InstructionSet::M68k::DataSize::LongWord) { \
SetupDataAccess(temporary_address_, Microcycle::Read, Microcycle::SelectWord); \
SetupDataAccess(Microcycle::Read, Microcycle::SelectWord); \
MoveToState(FetchOperand_l); \
} else { \
if constexpr (InstructionSet::M68k::operand_size<InstructionSet::M68k::Operation::x>() == InstructionSet::M68k::DataSize::Byte) { \
SetupDataAccess(temporary_address_, Microcycle::Read, Microcycle::SelectByte); \
SetupDataAccess(Microcycle::Read, Microcycle::SelectByte); \
} else { \
SetupDataAccess(temporary_address_, Microcycle::Read, Microcycle::SelectWord); \
SetupDataAccess(Microcycle::Read, Microcycle::SelectWord); \
} \
MoveToState(FetchOperand_bw); \
}
switch(instruction_.operation) {
CASE(NBCD)
CASE(NBCD, {
if(instruction_.mode(0) == Mode::DataRegisterDirect) {
perform_state_ = Perform_np_n;
} else {
perform_state_ = Perform_np;
}
FetchOperands(NBCD)
})
CASE(SWAP)
CASE(SWAP, perform_state_ = Perform_np);
CASE(MOVEw, perform_state_ = MOVEw);
CASE(CMPb, perform_state_ = Perform_np);
CASE(CMPw, perform_state_ = Perform_np);
CASE(CMPl, perform_state_ = Perform_np_n);
CASE(ANDb, perform_state_ = Perform_np);
CASE(ANDw, perform_state_ = Perform_np);
CASE(ANDl, {
if(instruction_.mode(1) == Mode::DataRegisterDirect) {
switch(instruction_.mode(0)) {
default:
perform_state_ = Perform_np_n;
break;
case Mode::DataRegisterDirect:
case Mode::ImmediateData:
perform_state_ = Perform_np_nn;
break;
}
} else {
perform_state_ = Perform_np;
FetchOperands(SWAP)
}
});
CASE(MOVEw)
perform_state_ = MOVEw;
FetchOperands(MOVEw)
CASE(ORb, perform_state_ = Perform_np);
CASE(ORw, perform_state_ = Perform_np);
CASE(ORl, {
if(instruction_.mode(1) == Mode::DataRegisterDirect) {
switch(instruction_.mode(0)) {
default:
perform_state_ = Perform_np_n;
break;
case Mode::DataRegisterDirect:
case Mode::ImmediateData:
perform_state_ = Perform_np_nn;
break;
}
} else {
perform_state_ = Perform_np;
}
});
CASE(EORb, perform_state_ = Perform_np);
CASE(EORw, perform_state_ = Perform_np);
CASE(EORl, {
if(instruction_.mode(1) == Mode::DataRegisterDirect) {
perform_state_ = Perform_np_nn;
} else {
perform_state_ = Perform_np;
}
})
default:
assert(false);
@ -403,19 +454,18 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
BeginState(FetchAddressRegisterIndirect_bw):
effective_address_[next_operand_] = registers_[8 + instruction_.reg(next_operand_)].l;
SetDataAddress(effective_address_[next_operand_]);
temporary_address_ = effective_address_[next_operand_];
Access(operand_[next_operand_].low); // nr
MoveToNextOperand(FetchOperand_bw);
// TODO: avoid use of temporary_address_ here and probably above.
BeginState(FetchAddressRegisterIndirect_l):
effective_address_[next_operand_] = registers_[8 + instruction_.reg(next_operand_)].l;
SetDataAddress(effective_address_[next_operand_]);
temporary_address_ = effective_address_[next_operand_];
Access(operand_[next_operand_].high); // nR
temporary_address_ += 2;
effective_address_[next_operand_] += 2;
Access(operand_[next_operand_].low); // nr
MoveToNextOperand(FetchOperand_l);
@ -436,14 +486,15 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
}
SetupDataAccess(
effective_address_[next_operand_],
0,
(instruction_.operand_size() == InstructionSet::M68k::DataSize::Byte) ? Microcycle::SelectByte : Microcycle::SelectWord);
SetDataAddress(effective_address_[next_operand_]);
Access(operand_[next_operand_].low); // nw
MoveToState(Decode);
BeginState(StoreOperand_l):
SetupDataAccess(effective_address_[next_operand_], 0, Microcycle::SelectWord);
SetupDataAccess(0, Microcycle::SelectWord);
SetDataAddress(effective_address_[next_operand_]);
Access(operand_[next_operand_].low); // nw
effective_address_[next_operand_] -= 2;
@ -470,6 +521,13 @@ void Processor<BusHandler, dtack_is_implicit, permit_overrun, signal_will_perfor
IdleBus(1); // n
MoveToWritePhase();
BeginState(Perform_np_nn):
InstructionSet::M68k::perform<InstructionSet::M68k::Model::M68000>(
instruction_, operand_[0], operand_[1], status_, *static_cast<ProcessorBase *>(this));
Prefetch(); // np
IdleBus(2); // nn
MoveToWritePhase();
#undef MoveToWritePhase