Why do integers process faster than bytes on NDS?

Question

i've noticed that my nds application works a little faster when I replace all the instances of bytes with integers. all the examples online put u8/u16 instances whenever possible. is there a specific reason as to why this is the case?

Answer 1

The main processor the Nintendo DS utilizes is ARM9, a 32-bit processor.

Reference: http://en.wikipedia.org/wiki/ARM9

                    

Typically, CPU will conduct operations in word sizes, in this case, 32-bits. Depending on your operations, having to convert the bytes up to integers or vice-versa may be causing additional strain on the processor. This conversion and the potential lack of instructions for values other than 32-bit integers may be causing the lack of speed.