On Friday, 9 June 2017 at 18:32:06 UTC, Steven Schveighoffer
wrote:
Wow, so that's how D code would look like if it were C++ :)
Well, I cannot (and did not try to) hide where I am coming from.
;-)
The results are quite disappointing. What seems particularly
strange to
me is that -boundscheck=off leads to a performance decrease.
That doesn't make much sense, but I'm not an ldc2 user.
However, it does note in the help that -release disables bounds
checks already.
Sounds like a bug, then.
I did replicate that issue on my box, and mucking around with
the implementation didn't help.
In answer to the subject, no D is not slow. However, it's quite
possible that std.algorithm.bringToFront is slower than
std::rotate, or SortedRange.upperBound is slower than
std::upper_bound, or both. I don't think it's a design issue
per se, probably more of an implementation issue.
Thank you for confirming the results and your factual explanation
notwithstanding my pointed question. ;-)
Maybe I was expecting too much given Andrei's performance
oriented talks. I realize that the conceptual groundwork is more
important than a concrete implementation that can be easily
improved. However, I think that real world out-of-the-box
performance - particularly with respect to toy examples (since
those are small enough to be literally translated) - is important
for prospects to gain confidence in buying into D.
At the current state, at least for such benchmarks, I think, I
should not rely on standard library facilities. Unfortunately,
that does not increase my confidence.
