On Fri, 12 Mar 2021 at 09:38, Kito Cheng <kito.ch...@gmail.com> wrote: > > Hi Jonathan: > > > > C++ also has another proposal for extended floating-point types > > > (https://wg21.link/p1467), which included half-precision types, so in > > > my understanding, _Float16 won't be a portable typen between C/C++. > > > > Why not just make _Float16 available in C++ as a GCC extension? > > Not sure it would introduce any ABI issue or not? Especially the function > name mangling for _Decimal* types, or maybe we could just implement the > interchanged floating point type (_FloatN) part to C++ is fine?
I would forget about the decimal types. I thought you were just talking about _Float16? You will need to decide on a mangling for it in C++, which should be co-ordinated with other compilers that are likely to support the type. You could mangle it as "u8_Float16" which is in the namespace reserved for vendor-extensions but if you wanted to assign a new shorter, non-extension then it should be discussed at https://github.com/itanium-cxx-abi/cxx-abi/issues (which will need to happen anyway if std::float16 is expected to go into the C++ standard). Are you planning to support this in Clang too?
