[PATCH] D107829: SplitKit: Don't further split subrange mask in buildCopy

Tue Aug 10 08:05:34 PDT 2021

arsenm accepted this revision.
arsenm added a comment.
This revision is now accepted and ready to land.

In D107829#2937029 <https://reviews.llvm.org/D107829#2937029>, @ruiling wrote:

> In D107829#2937013 <https://reviews.llvm.org/D107829#2937013>, @arsenm wrote:
>
>> I'm currently working on yet another patch for this which also apparently works. With this patch, can you delete the subrange handling in extendPHIKillRanges?
>
> Do you mean completely removing the code in the loop `for (LiveInterval::SubRange &PS : ParentLI.subranges())` in `SplitEditor::extendPHIKillRanges()`? I am not sure about this, I may need some further investigation.

Yes. I'm able to get every test to pass by removing it, and avoiding adding dead subrange defs if the incoming value is a phi def (although I still don't trust this is always correct)

This patch LGTM. Refining subranges after all the copies are inserted makes way more sense. Figuring out why extendPHIKillRanges needs to touch the subranges is another question

Repository:
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https://reviews.llvm.org/D107829