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remove unused function decrement_memory

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This commit is contained in:
Sam M W 2022-10-21 06:40:56 +01:00
parent 1d0fd6aad0
commit 4e057a2a94
1 changed files with 7 additions and 25 deletions
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32
src/cpu.rs
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@ -689,24 +689,6 @@ impl CPU {
);
}
fn decrement_memory(&mut self, addr: Address) {
let value_new = self.memory.get_byte(addr).wrapping_sub(1);
self.memory.set_byte(addr, value_new);
let is_negative = (value_new as i8) < 0;
let is_zero = value_new == 0;
self.registers.status.set_with_mask(
Status::PS_NEGATIVE | Status::PS_ZERO,
Status::new(StatusArgs {
negative: is_negative,
zero: is_zero,
..StatusArgs::none()
}),
);
}
fn jump(&mut self, addr: Address) {
self.registers.program_counter = addr;
}
@ -1062,31 +1044,31 @@ mod tests {
cpu.memory.set_byte(addr, 5);
cpu.decrement_memory(addr);
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
assert_eq!(cpu.memory.get_byte(addr), 4);
assert!(!cpu.registers.status.contains(Status::PS_ZERO));
assert!(!cpu.registers.status.contains(Status::PS_NEGATIVE));
cpu.decrement_memory(addr);
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
assert_eq!(cpu.memory.get_byte(addr), 3);
assert!(!cpu.registers.status.contains(Status::PS_ZERO));
assert!(!cpu.registers.status.contains(Status::PS_NEGATIVE));
cpu.decrement_memory(addr);
cpu.decrement_memory(addr);
cpu.decrement_memory(addr);
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
assert_eq!(cpu.memory.get_byte(addr), 0);
assert!(cpu.registers.status.contains(Status::PS_ZERO));
assert!(!cpu.registers.status.contains(Status::PS_NEGATIVE));
cpu.decrement_memory(addr);
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
assert_eq!(cpu.memory.get_byte(addr) as i8, -1);
assert!(!cpu.registers.status.contains(Status::PS_ZERO));
assert!(cpu.registers.status.contains(Status::PS_NEGATIVE));
cpu.memory.set_byte(addr, 0);
cpu.decrement_memory(addr);
cpu.execute_instruction((Instruction::DEC, OpInput::UseAddress(addr)));
assert_eq!(cpu.memory.get_byte(addr), 0xff);
assert!(!cpu.registers.status.contains(Status::PS_ZERO));
assert!(cpu.registers.status.contains(Status::PS_NEGATIVE));