[PATCH] D72997: [AMDGPU] SIRemoveShortExecBranches should not remove branches exiting loops

[Christudasan Devadasan via Phabricator via llvm-commits]

cdevadas added a comment.

You are right, the s_cbranch_execz shouldn't be removed from this loop exit BB.

But depending on the MachineLoopInfo to fix it is not good in general. There are irreducible control flows and the check may fail.

There is already a special check in function mustRetainExeczBranch, looking for loop code if the opcode is S_CBRANCH_VCCNZ & S_CBRANCH_VCCZ.
We should include S_CBRANCH_SCC0 & S_CBRANCH_SCC1 here. I hope this guarantees to be working for such cases.

If everyone agrees, I can create a patch and fix it.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D72997/new/

https://reviews.llvm.org/D72997