[PATCH] D108741: [GlobalDCE] Handle non-vfunc entries in vtables during VFE

[Kuba (Brecka) Mracek via Phabricator via llvm-commits]

kubamracek added a comment.

> It isn't great that VFE apparently relies on the type metadata that we added to support member function pointer CFI in C++. I was unaware that this was the case, and it shouldn't be necessary for frontends that don't have something like C++'s peculiar member function pointer ABI (I assume that Swift doesn't?) It would be better if we designed an independent way of marking these entries as subject to VFE.

As far as I can tell, VFE was added via https://reviews.llvm.org/D63932 and it has since always used type metadata and the !type annotations on vtables. Are you asking for a reversal on how VFE is done at the IR level, including how it's done for C++ in Clang? I'd love to see more thought on that (and what exactly do you think the design should aim to do better), but it seems to me that that's out of scope for this particular small tweak that I'm pursuing.


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  https://reviews.llvm.org/D108741/new/

https://reviews.llvm.org/D108741