[clang] [llvm] [clang][CodeGen][AA] Add `!llvm.errno.tbaa` gathering int-compatible TBAA nodes (PR #125258)

[Nikita Popov via llvm-commits]

nikic wrote:

> > > so IIUC !llvm.errno.tbaa should just be a module-level list of int-compatible TBAA nodes.
> > 
> > 
> > Yes, exactly. It should be a module level MD node, not on individual instructions.
> 
> Thank you, I'm updating this. I've been contemplating this, and thought originally we needed to extend TBAA (like aliasErrno as per tmp commit, provided it is correct), but TBAA seems to take care of this already (as clang propagates int TBAA correctly to the call), so I think this shouldn't be needed.

The fact that clang currently places TBAA on FP libcalls is a hack that we want to remove. It doesn't work for libcalls that also access other memory.


https://github.com/llvm/llvm-project/pull/125258