[PATCH] D86262: [LoopIdiomRecognizePass] Options to disable part or the entire Loop Idiom Recognize Pass

Tue Sep 1 08:17:23 PDT 2020

fhahn added a comment.

In D86262#2234176 <https://reviews.llvm.org/D86262#2234176>, @bmahjour wrote:

>> I think such an option is fine as a temporary stop-gap solution, but the goal should be to fix the underlying issue IMO.
>
> The long term solution would be to make loop-idiom consider compile-time or PGO loop trip count data when deciding to transform loops. For non-constant non-PGO cases the cost modeling would be a heuristic at best, in which case the option would still be useful.
>
>> Otherwise I am worried that the option reduces the incentive to fix the cost-modeling (which should be a fix-able issue).
>
> On the other hand, having an option makes it easier to identify opportunities and collect performance data for developing a cost model and tuning heuristics.

Sure, I am looking forward to patches improving the cost-modeling.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86262/new/

https://reviews.llvm.org/D86262