DMD Performance Regression Publisher [GSoC 2026]

[FinalEvilution]

On Thursday, 25 June 2026 at 17:51:10 UTC, Abul Hossain Khan 
wrote:

> Now as my mentor also suggested adding PGO (Profile Guided 
> Optimization) with the LDC2 build for even better results. I 
> didn't know much about PGO at first, but Dennis helped me 
> understand it and also shared his local build script with PGO 
> enabled with me. I think I've almost figured it out, so that 
> will be the next thing I work on.

+1 for PGO.
As far as I'm concerned everyone who is seriously optimizing for 
performance should be using PGO.
Modifying a build script to run the benchmark suite (if you don't 
have one what are you optimizing) and compile a second time is a 
pretty simple change, but I've seen up to a 30% decrease in run 
time... For just a makefile edit.

> **Semester exam**
> Yes I will have my semester exams from June 27 to July 3, so I 
> will be unavailable for about a week.

You're going to ace it.

> As always, feel free to leave any feedback or suggestions!

If memory serves perf has the ability to diff the performance of 
2 separate profiles on a per function basis. Might be handy.