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Muddle further towards data processing.

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This commit is contained in:
Thomas Harte 2024-02-26 14:50:45 -05:00
parent 030dda34f0
commit 580f402bb6
2 changed files with 56 additions and 18 deletions
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16
InstructionSets/ARM/OperationMapper.hpp
View File

@ -35,6 +35,22 @@ enum class DataProcessingOperation {
MVN, /// Rd = NOT Op2.
};
constexpr bool is_logical(DataProcessingOperation operation) {
switch(operation) {
case DataProcessingOperation::AND:
case DataProcessingOperation::EOR:
case DataProcessingOperation::TST:
case DataProcessingOperation::TEQ:
case DataProcessingOperation::ORR:
case DataProcessingOperation::MOV:
case DataProcessingOperation::BIC:
case DataProcessingOperation::MVN:
return true;
default: return false;
}
}
enum class Operation {
MUL, /// Rd = Rm * Rs
MLA, /// Rd = Rm * Rs + Rn

58
OSBindings/Mac/Clock SignalTests/ARMDecoderTests.mm
View File

@ -15,17 +15,18 @@ using namespace InstructionSet::ARM;
namespace {
template <ShiftType type>
void shift(uint32_t &source, uint32_t &carry, uint32_t amount) {
template <ShiftType type, bool set_carry>
void shift(uint32_t &source, uint32_t amount, uint32_t *carry = nullptr) {
switch(type) {
case ShiftType::LogicalLeft:
if(amount > 32) {
source = carry = 0;
if constexpr (set_carry) *carry = 0;
source = 0;
} else if(amount == 32) {
carry = source & 1;
if constexpr (set_carry) *carry = source & 1;
source = 0;
} else {
carry = source & (0x8000'0000 >> amount);
if constexpr (set_carry) *carry = source & (0x8000'0000 >> amount);
source <<= amount;
}
break;
@ -34,12 +35,21 @@ void shift(uint32_t &source, uint32_t &carry, uint32_t amount) {
}
}
void shift(ShiftType type, uint32_t &source, uint32_t &carry, uint32_t amount) {
template <bool set_carry>
void shift(ShiftType type, uint32_t &source, uint32_t amount, uint32_t *carry) {
switch(type) {
case ShiftType::LogicalLeft: shift<ShiftType::LogicalLeft>(source, carry, amount); break;
case ShiftType::LogicalRight: shift<ShiftType::LogicalRight>(source, carry, amount); break;
case ShiftType::ArithmeticRight: shift<ShiftType::ArithmeticRight>(source, carry, amount); break;
case ShiftType::RotateRight: shift<ShiftType::RotateRight>(source, carry, amount); break;
case ShiftType::LogicalLeft:
shift<ShiftType::LogicalLeft, set_carry>(source, amount, carry);
break;
case ShiftType::LogicalRight:
shift<ShiftType::LogicalRight, set_carry>(source, amount, carry);
break;
case ShiftType::ArithmeticRight:
shift<ShiftType::ArithmeticRight, set_carry>(source, amount, carry);
break;
case ShiftType::RotateRight:
shift<ShiftType::RotateRight, set_carry>(source, amount, carry);
break;
}
}
@ -55,12 +65,13 @@ struct Scheduler {
uint32_t operand2;
uint32_t rotate_carry = 0;
// Populate carry from the shift only if it'll be used.
constexpr bool shift_sets_carry = is_logical(flags.operation()) && flags.set_condition_codes();
if constexpr (flags.operand2_is_immediate()) {
if(!fields.rotate()) {
operand2 = fields.immediate();
} else {
operand2 = fields.immediate() >> fields.rotate();
operand2 |= fields.immediate() << (32 - fields.rotate());
operand2 = fields.immediate();
if(fields.rotate()) {
shift<ShiftType::RotateRight, shift_sets_carry>(operand2, fields.rotate(), &rotate_carry);
}
} else {
uint32_t shift_amount;
@ -71,7 +82,7 @@ struct Scheduler {
}
operand2 = registers_[fields.operand2()];
shift(fields.shift_type(), operand2, rotate_carry, shift_amount);
shift<shift_sets_carry>(fields.shift_type(), operand2, shift_amount, &rotate_carry);
}
switch(flags.operation()) {
@ -81,6 +92,16 @@ struct Scheduler {
default: break; // ETC.
}
// Set N and Z in a unified way.
if constexpr (flags.set_condition_codes()) {
status.set_nz(destination);
}
// Set C from the barrel shifter if applicable.
if constexpr (shift_sets_carry) {
status.set_c(rotate_carry);
}
}
template <Operation, Flags> void perform(Condition, Multiply) {}
@ -113,9 +134,10 @@ private:
- (void)testXYX {
Scheduler scheduler;
for(int c = 0; c < 65536; c++) {
InstructionSet::ARM::dispatch(c << 16, scheduler);
}
InstructionSet::ARM::dispatch(0xEAE06900, scheduler);
// const auto intr = Instruction<Model::ARM2>(1);
// NSLog(@"%d", intr.operation());
}
@end