[PATCH] D104618: [LoopDeletion] Exploit undef when symbolically executing 1st iteration

[Philip Reames via Phabricator via llvm-commits]

reames added a comment.

I would suggest splitting this into two patches.  The "ignore undef input in phi" is safe, and commonly done across the optimizer.  The "branch on undef" is tricky.  Just from a risk management perspective, I think it makes sense to split them into separate changes.

If you want to split, you can consider this an LGTM for the "ignore undef input in phi" part, and then continue this review for the "branch on undef" part.


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https://reviews.llvm.org/D104618