clang vs gcc build performance (executable not build time)

Luboš Luňák l.lunak at
Wed Nov 24 12:29:14 UTC 2021

On Tuesday 23 of November 2021, Luboš Luňák wrote:
> > > 	OpenSUSE 7.2 	Clang + libc++ 	Clang + std 	Gcc + std
> > > Run 1 	50,923045275 	45,456441587 	45,878275287 	49,487550577
>  Do you have more tests than this one? With the data you've provided that's
> good enough as an indicator that it should be investigated, but not much
> more, as there can be various factors that cause such results. Maybe Clang
> just happened to optimize better one function that's called often in this
> case, maybe one of the compilers is older than the older, maybe whatever
> else.
>  Can you try more different tests?

 By the way, if you're testing LO performance, you should use build settings 
that try to match what is used for release builds. You can find the setups in 
the distro-configs directory. In particular --enable-mergelibs --enable-lto 
are two flags that could have a significant impact on your results.

 Luboš Luňák
 l.lunak at

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