On Tue, Dec 10, 2019 11:13:47 +0100, Florian Weimer wrote:
* Ankur Sinha:
> -D_GLIBCXX_ASSERTIONS was added to the default build flags in F28[1].
> For one of my packages, upstream reports that this results in a 25% slow
> down[2], which is quite a lot.
>
> Has anyone else noticed such performance deterioration as a result of this?
We have seen cases where GCC cannot eliminate the bounds check in a
tight loop because the array index has the wrong type. This is arguably
a bug in the source code; fixing the type also addresses the performance
regression.
Apart from that, I don't know of any performance regressions. We would
have to look at profiles and disassembly to see what's going on in the
case of arbor-sim.
Thanks for your reply, Florian.
Upstream have dug in to this. Could you please have a look and suggest
what to do in this case?
https://github.com/arbor-sim/arbor/issues/917#issuecomment-564106931
--
Thanks,
Regards,
Ankur Sinha "FranciscoD" (He / Him / His) |
https://fedoraproject.org/wiki/User:Ankursinha
Time zone: Europe/London