[fpc-devel] The 15k bounty: Optimizing executable speed for Linux x86 / LLVM

Simon Kissel simon.kissel at nerdherrschaft.com
Fri Nov 23 14:36:01 CET 2018

Hi Adriaan,

> I find the phrase. "FPC's terrible multi-threading performance"
> unjust.

Well, see the complete thread to better understand what this
is about, and what progress is being made. So far a 20%
improvement has been made, which kinda is like a proof that
there was something to improve ;)

>  When I do multi-threading
> with FPC, I get a near N speed improvement (on i386 and x86_64) where N is the number of cores,
> including hyper-threaded cores ....

This isn't about FPC's code not scaling with N cores, it does.
It is about it being slow as soon as threads are used *at all*,
due to TLS stuff and exception handling. It's slow in a linear
fashion, so to say...

Best regards,


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