[PATCH] D132022: [SCEVExpander] Recompute poison-generating flags on hoisting. PR57187

[Nikita Popov via Phabricator via llvm-commits]

nikic added a comment.

In D132022#3755012 <https://reviews.llvm.org/D132022#3755012>, @nikic wrote:

> I'm confused. Why would the `nuw` be legal in the "old context"? Wouldn't we already branch on poison there as well, because `%iv.next` is used in `%loop.exit.cond` is used in br (unconditionally)?

Okay, the missing context here is that we create an additional IV with increment in the dead block and then perform a congruent IV replacement that hoists that increment and introduces uses in a live block.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D132022/new/

https://reviews.llvm.org/D132022