[PATCH] D137758: [HardwareLoops] remove loops which has undef count

[Florian Hahn via Phabricator via llvm-commits]

fhahn added inline comments.


================
Comment at: llvm/lib/CodeGen/HardwareLoops.cpp:447
+  // dedicated exit block, so we just delete these loops.
+  if (isa<UndefValue>(Count)) {
+    LLVM_DEBUG(dbgs() << " - Bailing, loop count is undef\n");
----------------
I doubt this is enough. I think you would at least have to ensure that the branch on undef is executed unconditionally in the loop. Also, shouldn't those dead loops be cleaned up earlier?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D137758/new/

https://reviews.llvm.org/D137758