[PATCH] D81981: [PGO] Supplement PGO profile with Sample profile

[David Li via Phabricator via llvm-commits]

davidxl added a comment.

If we don't need to handle all zero cases using scaling, we can remove the dependency on the always entry patch.



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Comment at: llvm/tools/llvm-profdata/llvm-profdata.cpp:400
+  InstrProfRecord *ProfRecord = IFE.ProfRecord;
+  if (!InstrEntryCount) {
+    // If the function is never executed in instrumentation profile,
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handling this case (all zero case) in this way won't help much -- The branch Probablity pass will set all branch weights to 1 making all branch unbiased -- it is worse than using static heuristic based.

The right way I think is to remove their profile entries completely. I assume the compiler pass later will treat such functions as unknown and not put into .text.unlikely.


Repository:
  rL LLVM

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https://reviews.llvm.org/D81981