> I'm not sure if the compiler is smart enough to do it for you, but you might be able to squeak a bit more performance by precomputing a partial sum (data + V_

> I'm not sure if the compiler is smart enough to do it for you, but you might be able to squeak a bit more performance by precomputing a partial sum (data + V_LEN - 1) outside the loop for this statement: I don't remember last time when a compiler did not do this for me. Compilers are generally pretty smart nowadays.