Vector performance

[F i L]

On Tuesday, 10 January 2012 at 14:14:41 UTC, Manu wrote:
> Just thought I might share a real-life case study today. Been a 
> lot of talk
> of SIMD stuff, some people might be interested.
>
> Working on an android product today, I noticed the matrix 
> library was
> burning a ridiculous amount of our frame time.
> The disassembly looked like pretty normal ARM float code, so 
> rewriting a
> couple of the key routines to use the VFPU (carefully), our key 
> device
> moved from 19fps -> 34fps (limited at 30, we can now ship).
> GalaxyS 2 is now running at 170fps, and devices we previously 
> considered
> un-viable can now actually get a release! .. Most devices saw 
> around 25-45%
> speed improvement.
>
> Imagine if all vector code throughout was using the vector 
> hardware nicely,
> and not just one or 2 key functions...
> Getting the API right (intuitively encouraging proper usage and 
> disallowing
> inefficient operations), it'll make a big difference!

Wow, impressive difference.

In the future, how will [your idea of] D's SIMD vector libraries 
effect my math libraries? Will I simply replace:

    struct Vector4(T) {
        T x, y, z, w;
    }

with something like:

    struct Vector4(T) {
        __vector(T[4]) values;
    }

or will std.simd automatically provide a full range of vector 
operations (normalize, dot, cross, etc) like mono.simd? I can't 
help but hope for the latter, even if it does make my current 
efforts redundant, it would defiantly be a benefit to future D 
pioneers.