From Philipp Klaus Krause@21:1/5 to All on Fri Sep 3 10:30:14 2021
Since C99, ptrdiff_t needs to have at least 17 bit. IMO, this places an unnecessary burden on 16-bit systems, and should be changed. The problem
was pointed out when the 17 bit requirement was introduced for C99, but
WG14 chose to go ahead anyway. By now time has shown that C compilers
targeting 16-bit systems just ignore that part of the standard, and
continue to use a 16-bit type.