[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 created this revision.
reames added reviewers: efriedma, nikic, fhahn.
Herald added subscribers: bollu, hiraditya, mcrosier.
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The basic idea here is that given a zero extended narrow IV, we can prove the inner IV to be NUW if we can prove there's a value the inner IV must take before overflow which must exit the loop.

This is a follow to D108651 <https://reviews.llvm.org/D108651>.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D109457

Files:
  llvm/lib/Analysis/ScalarEvolution.cpp
  llvm/test/Analysis/ScalarEvolution/trip-count-implied-addrec.ll

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