Preprocessor macro
#include <SYS/TYPES.H>
#ifdef __LONG_LONG_SUPPORTED
This macro is defined if the compiler supports long long and unsigned long long types. When this macro is defined, additional constants MAXLLONG, MINLLONG, MAXULLONG, __LLONG_SGN_BIT are defined.
The code may assume that types __u64 and __s64 are always present, but it should not assume that long long is present unless this macro is defined.