https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80886
--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This has nothing to do with __builtin_constant_p really.
Just GCC started to rejecting:
constexpr void *phardware {((void *) 0x1000)};
Starting in GCC 7; it was accepted before.
What is interesting is the __builtin_constant_p makes clang accept it but that
is a clang bug.
>This use appears to be documented
I don't think it was ever documented to be accepted this way but I could be
wrong.
