path tracing benchmark

[bearophile]

Christian Kamm:

> bearophile, just out of interest, what's the performance like if you ran 
> ldmd -O3 -release -inline smallpt2_d.d ?

I don't remember what ldmd is. Without LTO the performance of the LDC compile was a bit lower than the G++ compile.


> And why would internalizing _Dmain have a noticable performance impact?

It's the only way I have found to perform link-time-optimization with LDC1. It assumes the whole program is compiled at once, so it's able to perform more cross optimizations.

Bye,
bearophile