diff --git a/src/machine.rs b/src/machine.rs index e85837e..94d2c24 100644 --- a/src/machine.rs +++ b/src/machine.rs @@ -220,6 +220,14 @@ impl Machine { self.dec_x(); } + (instruction::EOR, instruction::UseImmediate(val)) => { + self.exclusive_or(val); + } + (instruction::EOR, instruction::UseAddress(addr)) => { + let val = self.memory.get_byte(addr); + self.exclusive_or(val); + } + (instruction::INC, instruction::UseAddress(addr)) => { let m = self.memory.get_byte(addr); let m = m + 1; @@ -688,6 +696,11 @@ impl Machine { self.compare(y, val); } + fn exclusive_or(&mut self, val: u8) { + let a_after = self.registers.accumulator ^ (val as i8); + self.load_accumulator(a_after); + } + fn push_on_stack(&mut self, val: u8) { let addr = self.registers.stack_pointer.to_address(); self.memory.set_byte(addr, val); @@ -1194,4 +1207,34 @@ fn compare_with_y_register_test() { }, instruction::LDY ); +} + +#[test] +fn exclusive_or_test() { + let mut machine = Machine::new(); + + for a_before in range(0u8, 255u8) { + for val in range(0u8, 255u8) { + machine.execute_instruction( + (instruction::LDA, instruction::UseImmediate(a_before)) + ); + + machine.exclusive_or(val); + + let a_after = a_before ^ val; + assert_eq!(machine.registers.accumulator, a_after as i8); + + if a_after == 0 { + assert!(machine.registers.status.contains(PS_ZERO)); + } else { + assert!(!machine.registers.status.contains(PS_ZERO)); + } + + if (a_after as i8) < 0 { + assert!(machine.registers.status.contains(PS_NEGATIVE)); + } else { + assert!(!machine.registers.status.contains(PS_NEGATIVE)); + } + } + } } \ No newline at end of file