narrowed down the problem area

[Tim Burrell]

downs wrote:
>> Strangely, Vec v = void; Vec.sub(center, ray.orig, v); runs in 8.8s, producing a correct output once the printf at the bottom has been fixed,
>> but Vec v = center - ray.orig; runs in 11.1s.
> 
> For some reason, the bad case, although inlined, stores its values back into memory. The fast case keeps working with them.
> 
> So it comes down to a GDC FP "bug". I think changing to 4.2 or 4.3 might help. Does anybody have an up-to-date version of the 4.2.x patch?

Hey good deal on figuring this out!  It's good to know, especially for
those of us using D for real-time simulation type stuff.

Is there really a GDC that compiles against gcc >= 4.2?!