On Thu, 22 Apr 2010 20:51:44 -0300, bearophile <bearophileh...@lycos.com>
wrote:
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.
Bye,
bearophile
Ray-tracers are insanely memory IO bound, not compute bound, bearophile.
So what you're seeing is the difference between 80-bits and 64-bits of
memory, not the FP performance.