N-body bench

[bearophile]

Stanislav Blinov:

> ldc2 -release -O3 -disable-boundscheck -vectorize 
> -vectorize-loops

All my versions of ldc2 don't even accept -vectorize :-)

ldc2: Unknown command line argument '-vectorize'.  Try: 'ldc2 
-help'
ldc2: Did you mean '-vectorize-slp'?

And -vectorize-loops should be active on default on recent 
versions of ldc2 (including V.0.12.1), and indeed I see no 
performance difference in using it.

Bye,
bearophile