[LLVMdev] where are my phi-nodes?

Fariborz Jahanian
Mon, 13 Sep 2010 18:43:02 -0000

On Sep 13, 2010, at 11:11 AM, John McCall wrote:

> On Sep 13, 2010, at 10:58 AM, Fariborz Jahanian wrote:
>>
> We do emit phis when the semantics aren't defined in terms of memory,
> e.g. with expressions that have multiple paths of control flow (like
> the
> conditional operator or null-checked derived-to-base conversions).

But at least for conditional operator, there are labels, conditionals
and branches.
Optimizer should be able to build the phi nodes from control flow. I
don't know
why not. But I am sure there is good reason for it being in the fe.
(maybe it makes
optimizer's work easier).

- fariborz

>
>
> John.