[Bug ipa/96337] [10/11 Regression] GCC 10.2: twice as slow for -O2 -march=x86-64 vs. GCC 9.3/8.4

[hubicka at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96337

--- Comment #4 from Jan Hubicka <hubicka at gcc dot gnu.org> ---
There was changes to -O2 inliner.  I have
 - enabled auto-inlininig
 - reduced early inlining a bit
 - reduced limits for inlining functions declared inline
The second two was needed to keep code size under control and did well on
overall -O2 spec and Firefox performance (without FDO, with FDO we indeed had
some performance loss and code size gains, which I plan to revisit).

This should not be visible on linux kernel though since it does always inline.
The linked patch to enable -O3 by default does not make too much sense to me. 

I will see if I can reproduce phoronix benchmarks - indeed those workloads are
not typical -O2 workloads and may be affected by the inline limits.

Honza