https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105509
--- Comment #1 from H.J. Lu <hjl.tools at gmail dot com> --- _Float16 was added for AVX512FP16 as a C++ extention. The fN suffixes were added by https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=c65699efcce48d68ef57ab3ce7fc5420fac5cbf9 which has C++ note: no support for the new types or constant suffixes is added for C++. C++ decimal floating-point support was very different from the C support, using class types, and the same may well apply to any future C++ bindings for IEEE interchange and extended types. There is a case, however, for supporting at least *f128 constants in C++, so that code using __float128 can use the newer style for constants throughout rather than needing to use the older *q constants in C++. Also, if built-in functions are added that may provide a way in which the types could leak into C++ code.
