Why is this code slow?

[Sergey]

On Thursday, 28 March 2024 at 20:18:10 UTC, rkompass wrote:
> D advantage is gone here, I would say.

It's hard to compare actually.
Std.parallelism has a bit different mechanics, and I think easier 
to use. The syntax is nicer.

OpenMP is an well-known and highly adopted tool, which is also 
quite flexible, but usually used with initially sequential code. 
And the syntax is not very intuitive.

Interesting point from Dr Russel here: 
https://forum.dlang.org/thread/qvksmhwkaxbrnggsvtxe@forum.dlang.org

However since 2012 OpenMP also got some development and 
improvement and HPC world is pretty conservative. So it is one of 
the most popular tool in the area: 
https://www.openmp.org/wp-content/uploads/sc23-openmp-popularity-mattson.pdf
With MPI.. But probably with AI and GPU revolution the balance 
will shift a bit to CUDA-like technologies.