[compiler-rt] [llvm] [TypeProf][InstrFDO]Omit vtable symbols in indexed profiles by default (PR #96520)

[Teresa Johnson via llvm-commits]

teresajohnson wrote:

> To clarify, are we currently including both compressed and uncompressed vtable names in the indexed profiles?

Nevermind, I misunderstood. We have either compressed or uncompressed names - and with this change we won't emit either (iiuc).

> > How much overhead does it add to the indexed profile?
> 
> I have a raw profile at hand for a search binary with large ELF size. Its raw profile size is 507M.
> 
> * With `--keep-vtable-symbol=true`, indexed profile `profile.profdata` is 901M.
> * With `--keep-vtable-symbol=false`, indexed profie `profile.profdata` is 893M.
> 
> So this is ~8M out of ~900M; but something nice to have (e.g., for deployment, and for faster indexed profile generation).

That's a fairly small decrease, but otoh I don't see a big downside since the names are there in the raw profile which is often available.

https://github.com/llvm/llvm-project/pull/96520