Problems with dmd inlining

[Jason House]

Walter Bright Wrote:

> Jason House wrote:
> > I wish I had your problems. I ported a sizable set of C++ code to D2 and
> > discovered D2 with dmd was 50x slower than C++ with gcc! I've been to
> > busy/disappointed to track down the bug(s) causing such a slowdown. If anyone
> > is sufficiently inspired to find the bugs, I can make the GPL source code
> > available.
> > 
> 
> 50 times slower is not likely to be a problem with inlining, it's likely to be 
> an algorithmic one.

Normally, yes, I'd agree. But in this case, it's merely a port of the C++ source code, so all algorithms are identical. The only change I did initially was to use ranges, but even after replacing those with mixins, the performance was equally as bad. There's also no memory allocations, so the GC isn't an issue either. There are also benchmarks on behavior that make me fairly confident the behavior is comparable.