[PATCH] D88535: CodeGen: Fix livein calculation in MachineBasicBlock splitAt

[Carl Ritson via Phabricator via llvm-commits]

critson added a comment.

In D88535#2303273 <https://reviews.llvm.org/D88535#2303273>, @arsenm wrote:

> Fix in what way? How was it broken before?

I have not fully root caused it, but if I apply D88537 <https://reviews.llvm.org/D88537> with splitAt as-is then I get code generation errors due to missing liveins.
Since the code sequence in splitAt is almost the same as that used by computeAndAddLiveIns, it seems logic to use that instead?

Looking at the code again for the moment, I think the problem is that SplitPoint (after increment) is missed in the stepBackward application.
i.e. the iteration needs to be inclusive of the whole range, not exclusive of the end point.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D88535/new/

https://reviews.llvm.org/D88535