[PATCH] D26359: Better handling of values missing in predecessors

[Matthias Braun via llvm-commits]

MatzeB added a comment.

- extendToUses(): This is a very similar algorithm than LiveRangeCalc::extend(), the difference is just that we can reuse the existing value numbers (and hence phi insertion points). Given that it is mostly the same I would expect this to require the same handling with an Undef array and using the extend(..., undef) variant as LiveRangeCalc.

- The extendPHIRange change looks fine. I did not check but I assume it is fine to wait with updating the main liverange because constructMainRangeFromSubranges() will be called anyway? So the SplitKit pieces are "LGTM" and could be put into a separate patch.


Repository:
  rL LLVM

https://reviews.llvm.org/D26359