On Fri, Oct 21, 2022 at 04:32:17PM +0000, Hipreme via Digitalmars-d-learn wrote:
> Hey guys, I have been complaining a lot of time right now from D compilation speed at least for my project.
> 
> I have:
> - Underused CTFE
> - Underused Templates
> - Avoided importing standard libraries
> - Created a multi module projects for better code reuse
> 
> Those are all the techniques I have tried to maintain my compilation times lower, yet, It still builds slow even when using the --combined (which does a single compiler run on dub)

Using dub immediately slows you down by at least several seconds. There may be some options to skip the time-consuming dependency graph resolution and network access.  But my personal preference is to use an offline build system with less overhead.


> So, doesn't matter if all is imported at once or not, it seems the problem seems to be somewhere in my project which I've been unable to find. I wanted to show someone who is more experienced on the time trace from LDC to check what I've been doing wrong.

LDC generally tends to be quite a bit slower than DMD because of the time spent in aggressive optimizations.  For development builds, consider using DMD instead.


> This time trace took 9 seconds. DMD takes 7 seconds to build my project.  Adam has built his entire arsd in 2.5 seconds, while my PC is faster and arsd is much bigger than my project, this does not make any sense.

It could be caused by a number of different things:

- Using many nested templates will slow down compilation.
- Doing excessive CTFE computations will slow things down.
- Using unusually-large static arrays in some cases may trigger slow
  paths in the front-end, consuming lots of compiler memory.
- Using string imports may slow things down as the compiler parses the
  imported file(s).
- Having excessively-large function bodies may trigger some O(n^2) paths
  in the compiler that significantly slows things down.
- Using excessive mixins may also slow things down due to copying of the
  AST.

OTOH, uninstantiated templates are cheap (the only cost is parsing them, which is very fast): just avoiding templates along may not save you much time if it's being spent elsewhere.  I suspect a good chunk of Adam's code is in uninstantiated templates, so a straight comparison isn't really fair, if those templates aren't actually being instantiated in the first place.

I also notice you use mixin templates a lot; it might be worth investigating whether they might be the cause of your issue.


> So I would gladly wish you guys help:
> 
> My repository: https://github.com/MrcSnm/HipremeEngine/
> My time trace: https://ufile.io/gmvw1wlu (This time trace will be in air for
> 30 days only)

Sorry, no time to look into it in detail, but I did skim over a few files and note that you use mixin templates a lot.  I haven't had much experience with mixin templates but it might be worth investigating whether they might be causing compile time slowdowns.


T

-- 
They say that "guns don't kill people, people kill people." Well I think the gun helps. If you just stood there and yelled BANG, I don't think you'd kill too many people. -- Eddie Izzard, Dressed to Kill