[PATCH] D95521: [SCEV] Apply loop guards to trailing zero bits

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:13277
+              auto ClearLowBits = getMulExpr(
+                  getUDivExpr(LHSUnknown, Divisor), Divisor,
+                  (SCEV::NoWrapFlags)(SCEV::FlagNUW | SCEV::FlagNSW));
----------------
gilr wrote:
> fhahn wrote:
> > Here we could just re-use the existing `URem` expression?
> Do you mean by computing `(A / B) * B` from the URem expression e.g. via `A - URemExpr`?
Nevermind, I was thinking about something else and we probably need the div & multiply to make sure the SCEV logic can determine the right multiple.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95521/new/

https://reviews.llvm.org/D95521