Building skia with clang(-cl)

[Stephan Bergmann]

On 23/04/2020 11:46, Miklos Vajna wrote:
> In short, I would like to hear what others think about using clang(-cl)
> for building skia.
> 
> Why? See this video from Lubos, showing skia raster performance on
> Windows: <https://youtu.be/iSo4wVtGQ2A>. Above is clang-cl, below is
> MSVC. The reason for the difference is that skia developers focus on
> good performance with clang, so building their codebase with gcc or msvc
> works, but the result is not as great as it could be. This would be the
> benefit.

FYI, 
<https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org/message/HWBXFXPFNNPZSB3OYW6DUKZUDSSGZJ7H/> 
"Re: Fedora 33 System-Wide Change proposal: CompilerPolicy Change":  "If 
I understand the LO case, it is just that LO sometimes uses the Skia 
library which is written by Google and Google likes compiler monoculture 
and is using heavily #ifdef __clang__ in it and using the clang variants 
of the generic vectors guarded by that, and as fallback just doesn't use 
simd.  I believe Honza Hubicka had quite some changes for Skia, not sure 
if they went
upstream already or not."

So at least for GCC the performance degradation when building skia with 
anything but Clang might eventually get addressed.