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Rebase onto master to pick up compiler errors and use load_x_register to simplify impl of dec_x. Because load_x_register sets the zero and negative status flags already

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This commit is contained in:
Alex Weisberger 2014-10-16 20:05:41 -04:00
parent 8fd38026aa
commit dd1d52ae24
1 changed files with 22 additions and 37 deletions
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59
src/machine.rs
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@ -205,23 +205,8 @@ impl Machine {
} }
pub fn dec_x(&mut self) { pub fn dec_x(&mut self) {
let x_before = self.registers.index_x; let val = self.registers.index_x;
let value = 1i8; self.load_x_register(val - 1);
let x_after = x_before - value;
self.registers.index_x = x_before - 1;
let is_negative = x_after < 0;
let is_zero = x_after == 0;
let mask = ps_negative | ps_zero;
self.registers.status.set_with_mask(
mask,
Status::new(StatusArgs {
negative: is_negative,
zero: is_zero,
..StatusArgs::none()
})
);
} }
} }
@ -312,25 +297,25 @@ fn dec_x_test() {
machine.dec_x(); machine.dec_x();
assert_eq!(machine.registers.index_x, -1); assert_eq!(machine.registers.index_x, -1);
assert_eq!(machine.registers.status.contains(ps_carry), false); assert_eq!(machine.registers.status.contains(PS_CARRY), false);
assert_eq!(machine.registers.status.contains(ps_zero), false); assert_eq!(machine.registers.status.contains(PS_ZERO), false);
assert_eq!(machine.registers.status.contains(ps_negative), true); assert_eq!(machine.registers.status.contains(PS_NEGATIVE), true);
assert_eq!(machine.registers.status.contains(ps_overflow), false); assert_eq!(machine.registers.status.contains(PS_OVERFLOW), false);
machine.dec_x(); machine.dec_x();
assert_eq!(machine.registers.index_x, -2); assert_eq!(machine.registers.index_x, -2);
assert_eq!(machine.registers.status.contains(ps_carry), false); assert_eq!(machine.registers.status.contains(PS_CARRY), false);
assert_eq!(machine.registers.status.contains(ps_zero), false); assert_eq!(machine.registers.status.contains(PS_ZERO), false);
assert_eq!(machine.registers.status.contains(ps_negative), true); assert_eq!(machine.registers.status.contains(PS_NEGATIVE), true);
assert_eq!(machine.registers.status.contains(ps_overflow), false); assert_eq!(machine.registers.status.contains(PS_OVERFLOW), false);
machine.load_x_register(5); machine.load_x_register(5);
machine.dec_x(); machine.dec_x();
assert_eq!(machine.registers.index_x, 4); assert_eq!(machine.registers.index_x, 4);
assert_eq!(machine.registers.status.contains(ps_carry), false); assert_eq!(machine.registers.status.contains(PS_CARRY), false);
assert_eq!(machine.registers.status.contains(ps_zero), false); assert_eq!(machine.registers.status.contains(PS_ZERO), false);
assert_eq!(machine.registers.status.contains(ps_negative), false); assert_eq!(machine.registers.status.contains(PS_NEGATIVE), false);
assert_eq!(machine.registers.status.contains(ps_overflow), false); assert_eq!(machine.registers.status.contains(PS_OVERFLOW), false);
machine.dec_x(); machine.dec_x();
machine.dec_x(); machine.dec_x();
@ -338,15 +323,15 @@ fn dec_x_test() {
machine.dec_x(); machine.dec_x();
assert_eq!(machine.registers.index_x, 0); assert_eq!(machine.registers.index_x, 0);
assert_eq!(machine.registers.status.contains(ps_carry), false); assert_eq!(machine.registers.status.contains(PS_CARRY), false);
assert_eq!(machine.registers.status.contains(ps_zero), true); assert_eq!(machine.registers.status.contains(PS_ZERO), true);
assert_eq!(machine.registers.status.contains(ps_negative), false); assert_eq!(machine.registers.status.contains(PS_NEGATIVE), false);
assert_eq!(machine.registers.status.contains(ps_overflow), false); assert_eq!(machine.registers.status.contains(PS_OVERFLOW), false);
machine.dec_x(); machine.dec_x();
assert_eq!(machine.registers.index_x, -1); assert_eq!(machine.registers.index_x, -1);
assert_eq!(machine.registers.status.contains(ps_carry), false); assert_eq!(machine.registers.status.contains(PS_CARRY), false);
assert_eq!(machine.registers.status.contains(ps_zero), false); assert_eq!(machine.registers.status.contains(PS_ZERO), false);
assert_eq!(machine.registers.status.contains(ps_negative), true); assert_eq!(machine.registers.status.contains(PS_NEGATIVE), true);
assert_eq!(machine.registers.status.contains(ps_overflow), false); assert_eq!(machine.registers.status.contains(PS_OVERFLOW), false);
} }