[PATCH] D34085: [PGO] Register promote profile counter updates

[David Li via Phabricator via llvm-commits]

davidxl marked an inline comment as done.
davidxl added a comment.

Added one more test case to show the merged live-in values from multiple predecessors in the loop.



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Comment at: lib/Transforms/Instrumentation/InstrProfiling.cpp:170
+      Instruction *InsertPos = InsertPts[i];
+      Value *LiveInValue = SSA.GetValueInMiddleOfBlock(ExitBlock);
+      Value *Addr = cast<StoreInst>(Store)->getPointerOperand();
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vsk wrote:
> This may be a basic question, but.. why is it that SSA.GetValueInMiddleOfBlock(ExitBlock) gives the right increment, coming from the promoted counter for {L, S}? It may help to have a short comment about this for readers who are unfamiliar with SSAUpdater (like me).
Added a comment. The name of the API is a little misleading -- it really means getting the LiveIn value (from the promoted counter stores) to the exit block.


https://reviews.llvm.org/D34085