Comment # 4 on bug 1160994 from Wolfgang Rosenauer

I can confirm a performance degradation related to (likely) graphics.
Compared 72.0.1 and 68.4.1 on my Leap 15.1 system:
- graphics from basemark moving faster
  72.0.1: 270
  68.4.1: 314

Just a very quick thought does not reveal larger differences in build and
patches between both.
Obviously some typical fluctuation in patches being obsolete or rebased.

So the difference between openSUSE versions of ESR and regular are VERY small.
Compared with upstream we use gcc instead of clang but as ESR is not (as much?)
affected as regular it somehow think that it's a combination of Firefox core
changes and probably toolchain.

As a first step I can switch from gcc to clang to see if that is related.