[PATCH] D120330: [MachineSink] Fix CFG walk in clobber check (PR53990)

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

In D120330#3339261 <https://reviews.llvm.org/D120330#3339261>, @shchenz wrote:

> Can we check why the instruction is sunk from a shallower block `From` to a deeper block `To`?  `MachineSinking::isProfitableToSinkTo()` should not allow this?

This happens because the loop is irreducible. The loop depth check is based on MachineLoopInfo, which only handles natural loops. So sinking into irreducible cycles is not prevented by the profitability check.


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https://reviews.llvm.org/D120330