[PATCH] D109457: [SCEV] Use constant range of RHS to prove NUW on narrow IV in trip count logic

[Philip Reames via Phabricator via llvm-commits]

reames added a subscriber: mkazantsev.
reames added a comment.

@nikic, @mkazantsev, @fhahn - Given the the must-exit logic has been removed and this is now pretty much just basic constant range reasoning, I'd greatly appreciate a review so we can get this in.  After implementing the indvars approach, I'm more convinced than ever that SCEV really should just be able to compute a trip count for these loops.  Everything else seems like a massive hack.


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  https://reviews.llvm.org/D109457/new/

https://reviews.llvm.org/D109457