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ch5- Fix se and sne implementation for cpu-4 #83

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ch5- Fix se and sne implementation for cpu-4 #83

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c992cd4
Update main.rs
tropicbliss Aug 10, 2022
0d90406
Set carry flag for and_xy
tropicbliss Aug 10, 2022
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13 changes: 7 additions & 6 deletions ch5/ch5-cpu4/src/main.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -59,14 +59,14 @@ impl CPU {
}

fn se(&mut self, vx: u8, kk: u8) {
if vx == kk {
if self.registers[vx as usize] == kk {
self.position_in_memory += 2;
}
}

/// () SNE **S**tore if **n**ot **e**qual
fn sne(&mut self, vx: u8, kk: u8) {
if vx != kk {
if self.registers[vx as usize] != kk {
self.position_in_memory += 2;
}
}
Expand Down Expand Up @@ -102,9 +102,10 @@ impl CPU {

// (7xkk)
fn add_xy(&mut self, x: u8, y: u8) {
self.registers[x as usize] += self.registers[y as usize];

// TODO: SET CARRY FLAG!!!!
/// Set carry flag
let (wrapped, is_overflow) = self.registers[x as usize].overflowing_add(self.registers[y as usize]);
self.registers[0xF] = if is_overflow {1} else {0};
self.registers[x as usize] = wrapped;
}

fn and_xy(&mut self, x: u8, y: u8) {
Expand Down Expand Up @@ -154,4 +155,4 @@ fn main() {
assert_eq!(cpu.registers[0], 45);

println!("5 + (10 * 2) + (10 * 2) = {}", cpu.registers[0]);
}
}