as GCC doesn't yet provide <stdint.h>, but as it changes GCC's understanding of the type of the built-in function imaxabs if nothing else, and of the types expected by printf %jd and %ju,it makes no sense without corresponding library changes to use such a bigger intmax_t, and such a library would have a different ABI from the
previous one
----------------------------
__int128_t m = 11111111111111111111;
printf("%jd",m);