Remove real type

[BCS]

Hello bearophile,

> BCS:
> 
>> If you have no special reason to use float or double and are not IO
>> or memory space bound, use real. Every machine I know the details of
>> will use it in the FPU so the only general advantage to not using it
>> is IO speed and data size.
>> 
> Take one of the little ray-tracers written in D from my site, test its
> running speed compiled with ldc, replace doubles with reals, and time
> it again. You will see a nice performance difference. LDC FP
> performance is not good if it doesn't use SSE registers.
> 

Ray tracing is very amiable to that sort of optimization, particularly if 
you are carful about how you write things. Also, I suspect that most cases 
where SSE is able to make a major difference will spend a lot of time moving 
large arrays through the CPU so they will have memory size and IO bottleneck 
concerns, exactly the cases I excepted.

-- 
... <IXOYE><