256*175=44800. This is well within the bounds of representing it as a floating point number.
Sinclair BASIC for example uses 1 exponent byte and 4 mantissa bytes.
I would think that as an inline function it expects a floating point number. It should work and not cause an overflow.
As a function it is coerced to an integer, passed on the stack as a 32-bit signed integer.
This would be done to make variable memory management easier.
Still got, still working: Atari 4Mb STe, 520STFM, 2.5Mb STF.
Hardware: Cumana CSA 354, Ultimate Ripper, Blitz Turbo, Synchro Express II (US and UK Versions).