[PATCH] D29866: [PDSE] Add PDSE.

[Davide Italiano via llvm-commits]

On Sun, Jun 18, 2017 at 11:56 PM, Daniel Berlin <dberlin at dberlin.org> wrote:
>>
>>
>> ================
>> Comment at: lib/Transforms/Scalar/PDSE.cpp:920
>> +    if (!PDT.getRootNode()) {
>> +      DEBUG(dbgs() << "FIXME: ran into the PDT bug. nothing we can
>> do.\n");
>> +      return false;
>> ----------------
>> Can you please describe the `PDT` bug? I'm not really familiar with it (or
>> I call it with another name :)
>>
>
> This is because the postdominator tree is *badly* broken in a myriad of
> ways.
>
> It's possible to hit this particular issue in a number of ways.
>
> In practice, we are going to have to fix post-dominators before we ever turn
> on this pass.
>

Oh. I'm aware of the PDT brokeness (I also have some examples) but I
thought you're referring to something specifically :)

Thanks!

--
Davide