On Tuesday, 24 September 2013 at 15:25:11 UTC, Andrei
Alexandrescu wrote:
What are they paying exactly? An extra arg to allocate that
can probably
be defaulted?
void[] allocate(size_t bytes, size_t align = this.alignment)
shared;
For allocating relatively small objects (say up to 32K), we're
looking at tens of cycles, no more. An extra argument needs to
be passed around and more importantly looked at and acted upon.
At this level it's a serious dent in the time budget.
The cost of a few cycles really doesn't matter for memory
allocation... If you are really allocating memory so frequently
that those few extra cycles matter then you are probably going to
be memory bound anyway.
I think this is a situation where you need to justify yourself
with something concrete. Can you provide an example of some code
whose performance is significantly impacted by the addition of an
alignment parameter? It has to be "real code" that does something
useful, not just a loop the continually calls allocate.
