@lucy "We don’t support 16-bit machines in GNU. "; https://www.gnu.org/prep/standards/html_node/CPU-Portability.html

16 bit is really a hackfest and 16 bit machines are really too slow to be useful as a general purpose computer and not supporting them to save a lot of development time and avoid nasty hacks was a design decision.

GCC does support outputting 16 bit code for 16 bit microcontrollers as a single program - which is what those kind of computers are good for.