AND faster than integer modulo operation?

Question

It is possible to re-express:

• i % m

as:

• i & (m-1)

where,

• i is an unsigned integer
• m is a po

Answer 1

ARM is very generic. There are lot of different ARMs and there are ARMs which do NOT have a division instruction (as Ray Toal already mentioned, modulo is usually implemented as additional result of the division implementation). So if you dont want to call a very slow division subroutine, the logical operation is much faster (and as cyco130 mentioned, any good compiler would recognize it on its own and generate the logical operation on its own - so for clearness of the program code I would stay with the division (except you program assembler, then you have of course to program it yourself, and then you should take the logical operation).