Comment by wmobit

The _fltused handling is quite crude: https://github.com/llvm/llvm-project/blob/5cfd02f44a43a2e2a0...

TLDR it's going to emit the reference if it's targeting MSVC and there's any float typed reference. You'd need to do something to avoid it, other than avoiding float types.

Presumably you are compiling for the MSVC ABI. Trying to plug your own runtime that doesn't behave exactly as the MSVC scheme isn't going to just work out of the box. The compiler has to know the details of the ABI you are targeting, if you're doing your own thing the compiler would need to treat that as a separate ABI. I'm not sure there's a triple now that means MSVC-like-freestanding.

The same logic applies on the clang driver side. The ABI expects to link those libraries, so it will.