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

[David Li via Phabricator via llvm-commits]

davidxl added a comment.

There is a use case that user check in indexed format profile for sources that do not change much (e.g. library code), thus the indexed format profile needs to be backward compatible. Raw profile has not such requirement.

For IR PGO, the compatibility requirement is nice to have, but it is probably not a hard requirement as there are other ways to easily break it -- for instance any early inliner changes or CFG cleanup pass changes can make the old profile unusable.

Also is it suffice to just never select the fake edge to entry in MST?


Repository:
  rL LLVM

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  https://reviews.llvm.org/D81981/new/

https://reviews.llvm.org/D81981