GNU Compiler Collection 9.2 version will be released next Monday, and before that, has released a release candidate for testing. GCC 9.2 offers a variety of bug fixes.
Since the beginning of 5 GCC 9.1.0 release, which mostly bug fixes, but added a noteworthy GCC 9.2 is an extension of AMD Zen 2 "Znver2" support, including cost update for AMD's new processor 7nm table and scheduling model. This support than initially Znver2 GCC 9 add much better, supports some new instructions, but no table adjustment costs and scheduling model.
These improvements are contributed by SUSE bit compiler personnel to the GCC 10, and then try to re-transplant GCC 9.2.
About GCC 9.2.0 release candidate See note: