[PATCH] D103118: [SCEV] Compute exit counts for unsigned IVs using mustprogress semantics

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:11398
+      if (getURemExpr(MaxVal, Stride) != StrideMinusOne)
+        return false;
+
----------------
Could you just check that Stride is a power of 2 here? This seems overly complicated.

Could you separate out checking "there must be some value of LHS that forces the loop to exit" from "the IV can't wrap"?  We can use the former to compute a max backedge taken count even if we can't prove the IV doesn't wrap.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103118/new/

https://reviews.llvm.org/D103118