[PATCH] D134152: [SimplifyCFG][TranformUtils]Do not simplify away a trivial basic block if both this block and at least one of its predecessors are loop latches.

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

The current representation of loop metadata (using a loop latch terminator attachment) is known to be fundamentally broken. Loop latches are not uniquely associated with loops (both in that a latch can be part of multiple loops and a loop may have multiple latches). Loop headers are. The solution to this problem is also known: Add support for basic block metadata, and attach loop metadata to the loop header.

I don't think adding these kinds of hacks is going to scale much further -- someone needs to actually address the root problem.


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  https://reviews.llvm.org/D134152/new/

https://reviews.llvm.org/D134152