[PATCH] D76135: [MachineLICM] Don't treat cross copies as cheap

[Matt Arsenault via Phabricator via llvm-commits]

arsenm added inline comments.


================
Comment at: llvm/lib/CodeGen/MachineLICM.cpp:1179-1181
+  if (isCrossCopy(MI))
+    return false;
   if (TII->isAsCheapAsAMove(MI) || MI.isCopyLike())
----------------
I'd like to get somebody else's opinion on this too. Based on the isAsCheapAsAMove check, I'm not sure what the intended handling of copies is here. For AMDGPU for example, copies get more expensive with wider register classes, which isn't a property of the register bank


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D76135/new/

https://reviews.llvm.org/D76135