GCC 8 vs. GCC 9 speed and size comparison

[Michael Matz]

Hi,

On Mon, 15 Apr 2019, Martin Liška wrote:

> There's a similar comparison that I did for the official openSUSE gcc 
> packages. gcc8 is built with PGO, while the gcc9 package is built in 2 
> different configurations: PGO, LTO, PGO+LTO (LTO used for FE in stage4, 
> for generators in stage3 as well).
> 
> Please take a look at attached statistics.

It seems the C++ parser got quite a bit slower with gcc 9 :-( Most visible 
in the compile time for tramp-3d (24%) and kdecore.cc (18% slower with 
just PGO); it seems that the other .ii files are C-like enough to not 
trigger this behaviour, so it's probably something to do with templates 
and/or classes.


Ciao,
Michael.