dlib - d utility library

[Jacob Carlborg]

On 2012-09-28 19:47, Peter Alexander wrote:

> A note on your Vector implementation. Currently you use the vector
> operators, e.g.
>
>      Vector!(T,size) opAddAssign (Vector!(T,size) v)
>      body
>      {
>          arrayof[] += v.arrayof[];
>          return this;
>      }
>
> This is fine for large vectors, but (correct me if I'm wrong), your
> vector class appears to be designed for small vectors. Those vector ops
> currently call a asm optimised function that uses SIMD instructions in a
> loop - it works well for larger vectors with hundreds of elements, but
> for small vectors it's significantly faster to just use:
>
> foreach (i; 0..size)
>      arrayof[i] += v.arrayof[i];

Isn't the whole point of the array operators that it gives the compiler 
more semantic understanding of the code. Just as a foreach-loop does 
compared to a for-loop. So the compiler should be able to optimize this 
and generated the most optimal code. But the compiler might not be that 
good.

-- 
/Jacob Carlborg