> I guess the answer to both questions is that most TCO opportunities are within a single DLL, so the compiler is free to create non-exported versions of functi

> I guess the answer to both questions is that most TCO opportunities are within a single DLL, so the compiler is free to create non-exported versions of functions with custom calling conventions. Is this right? LLVM mostly follows this path: it allows full TCO only when using the “fastcc” (i.e. “whatever LLVM feels like generating”) and some calling conventions from functional languages (like GHC) that have a specific carve out for it.