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

If m is known at compile time (or even it it isn't) integer division and modulo can be re-expressed using multiplication by a magic "multiplicative inverse." The result of the division ends up in the high 32 bits and the remainder (modulus) in the lower 32 bits:

http://www.hackersdelight.org/magic.htm

The following link claims that it is a standard compiler strength reduction:

http://www.flounder.com/multiplicative_inverse.htm