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

[David Li via Phabricator via llvm-commits]

davidxl added a comment.

See the summary for precision data. With this patch, the multi-threaded counter value is much closer to the single threaded case with very little loss.

It is unlikely that loops with calls to no-return function can be in the hot paths.  Regardless, the patch already  disables promotion for such loops (with multiple existing blocks). If we want to improve training run performance for such loops, we can make enhancement insert counter flush before the noreturn calls.


https://reviews.llvm.org/D34085