[Interest] slower compilation with Qt6
Hamish Moffatt
hamish at risingsoftware.com
Mon Jul 24 10:23:19 CEST 2023
On 24/7/23 17:01, Cristian Adam wrote:
> The compilation time degradation is being tracked at [QTBUG-97601]
> Compilation speed decrease with Qt 6.2 compared to Qt 5.15.2 - Qt Bug
> Tracker <https://bugreports.qt.io/browse/QTBUG-97601>
>
> For Qt Creator I use https://ccache.dev/ (yes, it works with MSVC) so
> that even if it takes longer to compile, I won't be compiling the same
> file in same situation twice.
Thanks, good to know this a known issue with work in progress. I do use
ccache on my linux builds, though I'm finding it increasingly unreliable
with PCH enabled so I will have to decide which is more useful.
My test compile results for 5.15.13 versus 6.5.2 are even worse than the
figures you reported in that issue.
For a project with ~600 TUs, compiled on linux with clang 14, PCH on but
no ccache, I see 40 seconds -> 96 seconds.
For another project with ~900 TUs, compiled with MSVC 2022 with jom, PCH
on but no ccache, I see 178 seconds -> 332.
I compile with CONFIG += c++2a on both Qt versions.
Hamish
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20230724/9c565ced/attachment.htm>
More information about the Interest
mailing list