[PATCH] D159050: [PowerPC] set min jump table entries to 64

[Nemanja Ivanovic via Phabricator via llvm-commits]

nemanjai accepted this revision.
nemanjai added a comment.
This revision is now accepted and ready to land.

The reason 64 seems to be a good value on PPC chips is hopefully a transient situation that seems to have something to do with how bad the chips can be with branch prediction for indirect branches (CTR branches). I think at least some indication should be added in code comments suggesting this be re-evaluated on future HW that will hopefully do better with this kind of branch.
The other knob we have access to wrt. jump tables (density) could probably use some tuning as well.

Other than the above (which doesn't require another review), LGTM.


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https://reviews.llvm.org/D159050