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using the associated function decrement

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This commit is contained in:
Sam M W 2022-10-21 06:33:40 +01:00
parent 665ee4193d
commit 95731752ba
1 changed files with 9 additions and 9 deletions
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18
src/cpu.rs
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@ -207,16 +207,16 @@ impl CPU {
self.compare_with_y_register(val);
}
(Instruction::DEC, OpInput::UseAddress(addr)) => self.decrement_memory(addr),
(Instruction::DEC, OpInput::UseAddress(addr)) => {
CPU::decrement(&mut self.memory.get_byte_mut_ref(addr), &mut self.registers.status);
}
(Instruction::DEY, OpInput::UseImplied) => {
let mut r = u8::from_ne_bytes(self.registers.index_y.to_ne_bytes());
self.decrement(&mut r);
self.load_y_register(r);
CPU::decrement(&mut self.registers.index_y, &mut self.registers.status);
}
(Instruction::DEX, OpInput::UseImplied) => {
self.dec_x();
CPU::decrement(&mut self.registers.index_x, &mut self.registers.status);
}
(Instruction::EOR, OpInput::UseImmediate(val)) => {
@ -672,14 +672,14 @@ impl CPU {
self.load_accumulator(result);
}
fn decrement(&mut self, val: &mut u8) {
fn decrement(val: &mut u8, flags: &mut Status) {
let value_new = val.wrapping_sub(1);
*val = value_new;
let is_negative = (value_new as i8) < 0;
let is_zero = value_new == 0;
self.registers.status.set_with_mask(
flags.set_with_mask(
Status::PS_NEGATIVE | Status::PS_ZERO,
Status::new(StatusArgs {
negative: is_negative,
@ -708,8 +708,8 @@ impl CPU {
}
fn dec_x(&mut self) {
let mut r = u8::from_ne_bytes(self.registers.index_x.to_ne_bytes());
self.decrement(&mut r);
let mut r = self.registers.index_x;
CPU::decrement(&mut r, &mut self.registers.status);
self.load_x_register(r);
}