Dead Code Elimination

[Richard (Rikki) Andrew Cattermole]

On 19/10/2026 7:36 PM, Walter Bright wrote:
> On 10/18/2026 8:33 AM, libxmoc wrote:
>> I noticed that dmd doesn't do DCE
> 
> Yes, it does. Use the -O switch.

dmd -O

```d
void main() {

}

void foo() {
}
```

```asm.text._Dmain	segment
	assume	CS:.text._Dmain
_Dmain:
		push	RBP
		mov	RBP,RSP
		xor	EAX,EAX
		pop	RBP
		ret
.text._Dmain	ends
.text.void onlineapp.foo()	segment
	assume	CS:.text.void onlineapp.foo()
void onlineapp.foo():
		push	RBP
		mov	RBP,RSP
		pop	RBP
		ret
		add	[RAX],AL
.text.void onlineapp.foo()	ends
```