Required DMD changes for Mir and few thoughts about D future

[Andrei Alexandrescu via Digitalmars-d]

On 9/27/16 1:33 PM, Johan Engelen wrote:
> I thought so too but if the algorithm is 50x slower, it probably means
> you can't develop that algorithm any more (I wouldn't). I think the
> common use-case for Mir is a calculation that takes seconds, so 50x
> turns a test into a run of several minutes, defeating the compilation
> speed advantage of DMD. The way I see it, faster development with
> Mir+DMD is not possible.

Yes, 50x is not going to pass. In my experience, generally (not for 
numerics code) dmd generated code is somewhat in between 5% faster and 
40% slower. I'd say if we get it within the same range for Ilya's 
library we can call it a successful port.

> It is easy to want something, but someone else has to do it and live
> with it too. It's up to the Mir devs (**volunteers!**) to choose which
> compilers they support. As you can see from the PR that removed DMD
> support, the extra burden is substantial.
> https://github.com/libmir/mir/pull/347

We need to do what it takes to make dmd work with Mir properly.

> An extra subjective comment from recent experience: I think LDC has been
> very responsive to Mir's needs, thinking _with_ Mir development instead
> of fighting it and debating things to death. Imagine you are developing
> Mir, want to get something done, and then read the discussion starting here
> https://forum.dlang.org/post/brieiuuuslpzfeioxuql@forum.dlang.org
> The LDC PR with the requested functionality was submitted less than two
> weeks after
> (pull was stalled because we don't control our own frontend).

That's far from the worst we've had, but I agree that generally the 
endless debates are often gridlocking our progress.


Andrei