[PATCH] D103816: [SimpleLoopUnswich] Fix a bug on ComputeUnswitchedCost with partial unswitch

[Sanne Wouda via Phabricator via llvm-commits]

sanwou01 added inline comments.


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Comment at: llvm/lib/Transforms/Scalar/SimpleLoopUnswitch.cpp:2875
             continue;
-        } else if (!PartialIVInfo.InstToDuplicate.empty()) {
+        } else if (PartialIVCondBranch == &TI) {
           if (PartialIVInfo.KnownValue->isOneValue() &&
----------------
Isn't this always true for a partial unswitch? If there is a partial unswitch candidate, PartialIVCondBranch will be the terminator of the loop header. When ComputeUnswitchedCost is called for a partial unswitch TI is *also* the terminator of the loop header. Did I miss something?

FWIW I also think that the previous condition is always true: for a partial unswitch, there is always at least one instruction in InstToDuplicate. (again, the terminator of the loop header!)


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D103816/new/

https://reviews.llvm.org/D103816