[llvm-branch-commits] [clang] [llvm] [clang] Function Multi Versioning supports IFunc lowerings on Darwin platforms (PR #73688)

[Jon Roelofs via llvm-branch-commits]

jroelofs wrote:

> Will this cause an ABI compatibility issue for any existing use of the function multiversioning attributes on Darwin? I think it might, but I haven't tried to confirm.

I don't think there is an ABI compatibility concern here for a couple of reasons:
* The corresponding builtins were unimplemented on Darwin until https://github.com/llvm/llvm-project/pull/73685 (FYI, this is part of a patch series: #73688, #73687, #73686, #73685)
* On AArch64, the IFunc lowering is required: https://github.com/llvm/llvm-project/blob/859338a695169d2804d6999f44e1e94bedf6ddd7/clang/lib/CodeGen/CodeGenFunction.cpp#L2746-L2748

https://github.com/llvm/llvm-project/pull/73688