AMD Zen 2 "Znver2" Compiler Optimizations Back-Ported For GCC 9.2 Compiler

Last week I wrote about the GCC 10 compiler picking up a new scheduler model and cost tables for AMD Zen 2 CPUs to build off the initial "znver2" microarchitecture target from last year. Fortunately, those Znver2-specific improvements have now been back-ported to the GCC 9 compiler branch so it will see user systems with not as long of a wait until GCC 10 stable.

SUSE compiler engineer Jan Hubicka who worked out the scheduler model and cost table adjustments for Znver2 has now back-ported the changes to gcc-9-branch. With GCC 10.1 as the first GCC 10 stable release not due out until Q2'2020, this back-porting will allow it to see user systems sooner.

GCC 9.2.0 should be out within the next month or two if their past x.2.0 timing is any indication. Though whether that will align for getting this minor bug-fix release into Ubuntu 19.10, Fedora 31, or others, remains to be seen.

Hopefully for future CPU launches, AMD is able to improve their compiler enablement alignment similar to Intel where it comes out well in advance so as not to worry about software release schedules post-launch for getting out this optimized support.

Yesterday I did wrap up compiler benchmarks of the new GCC 10 Znver2 code and will be publishing those results tomorrow.