bearophile wrote:
Rainer Deyke:
D's performance is unexpectedly bad, so much that I expect that it might be using
dynamic memory allocation anyway despite the 'scope' keyword. Java is clever in
that it eliminates unnecessary dynamic memory allocations automatically.<
I think Java here is doing a bit more than just removing the dynamic
allocation. I don't think D (compiled with LDC) is doing doing any allocation
here. I'll ask to the LDC IRC channel.
LDC actually still does a dynamic allocation there because it doesn't eliminate
dynamic allocations in loops.
This is unfortunate, but I haven't yet had the time to figure out how to get the
optimization passes to prove the allocation can't be live when reached again.
(If multiple instances of memory allocated at the same allocation site may be
reachable at the same time, it's not safe to use a stack allocation instead of a
heap allocation)
It's on my to-do list, though.
