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Introduces first DIVS test, and associated fixes.

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This commit is contained in:
Thomas Harte 2019-06-20 19:02:03 -04:00
parent bcf6f665b8
commit fafd1801fe
2 changed files with 33 additions and 3 deletions
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27
OSBindings/Mac/Clock SignalTests/68000Tests.mm
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@ -58,6 +58,7 @@ class RAM68000: public CPU::MC68000::BusHandler {
HalfCycles perform_bus_operation(const CPU::MC68000::Microcycle &cycle, int is_supervisor) {
const uint32_t word_address = cycle.word_address();
duration_ += cycle.length;
using Microcycle = CPU::MC68000::Microcycle;
if(cycle.data_select_active()) {
@ -101,10 +102,15 @@ class RAM68000: public CPU::MC68000::BusHandler {
return m68000_;
}
int get_cycle_count() {
return 0;
}
private:
CPU::MC68000::Processor<RAM68000, true, true> m68000_;
std::vector<uint16_t> ram_;
int instructions_remaining_;
HalfCycles duration_;
};
class CPU::MC68000::ProcessorStorageTests {
@ -1038,7 +1044,26 @@ class CPU::MC68000::ProcessorStorageTests {
[self performDBccTestOpcode:0x5fca status:Flag::Negative | Flag::Overflow d2Outcome:0];
}
/* Further DBF tests omitted. */
/* Further DBF tests omitted; they seemed to be duplicative, assuming I'm not suffering a failure of comprehension. */
// MARK: DIVS
- (void)testDIVSOverflow {
_machine->set_program({
0x83fc, 0x0001 // DIVS #1, D1
});
auto state = _machine->get_processor_state();
state.data[1] = 0x4768f231;
state.status = Flag::ConditionCodes;
_machine->set_processor_state(state);
_machine->run_for_instructions(2);
state = _machine->get_processor_state();
XCTAssertEqual(state.data[1], 0x4768f231);
XCTAssertEqual(state.status & Flag::ConditionCodes, Flag::Extend | Flag::Negative | Flag::Overflow);
// Test: 20 cycles passed.
}
// MARK: MOVE USP

9
Processors/68000/Implementation/68000Implementation.hpp
View File

@ -1022,16 +1022,21 @@ template <class T, bool dtack_is_implicit, bool signal_will_perform> void Proces
cycles_expended += 2; // An additional microycle applies if the dividend is negative.
}
carry_flag_ = 0;
// These are officially undefined for results that overflow, so the below is a guess.
zero_result_ = decltype(zero_result_)(quotient & 0xffff);
negative_flag_ = zero_result_ & 0x8000;
// Check for overflow. If it exists, work here is already done.
if(quotient > 32767 || quotient < -32768) {
overflow_flag_ = 1;
active_step_->microcycle.length = HalfCycles(3*2*2);
break;
}
overflow_flag_ = 0;
zero_result_ = decltype(zero_result_)(quotient);
negative_flag_ = zero_result_ & 0x8000;
// TODO: check sign rules here; am I necessarily giving the remainder the correct sign?
// (and, if not, am I counting it in the correct direction?)