Sorry, but I fail to see where the problem is. Any general purpose ISA designed in the past 40 years can handle 8/16/32 bit integers just fine regardless of the register size. That includes the 64-bit x86-64 or ARM64 from which you are typing.

The are a few historical architectures that couldn't handle smaller integers, like the first generation Alpha, but:

    a) those are long dead.

    b) hardware engineers learnt from their mistake and no modern general purpose architecture has repeated it (specialized architectures like DSP and GPU are another story though).

    c) worst case scenario, you can simulate it in software.