[PATCH] D93973: [SCEV] Simplify trunc to zero based on known bits

[Nikita Popov via Phabricator via llvm-commits]

nikic added inline comments.


================
Comment at: llvm/lib/Analysis/ScalarEvolution.cpp:1157
+  if (MinTrailingZeros >= getTypeSizeInBits(Ty))
+    return getZero(Ty);
+
----------------
This check should be lower in the function. Certainly doesn't make sense to do this before the folding set lookup or the constant folding. I think the right position is directly before a new SCEVTruncateExpr is allocated, i.e. after trunc has already been pushed through operations where possible.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D93973/new/

https://reviews.llvm.org/D93973