I am looking for GCC optimization options described in this article:
GCC has its own target for the Jaguar SoCs. You can optimise by using the -march=btver2 -mtune=btver2 GCC options, with a recent GCC version. In the buildroot, enable Advanced configuration options (for developers), then tick Target Options and add the compiler flags to Target Optimizations. Do keep in mind though this will greatly limit your testing capabilites - I haven't found a way to emulate a CPU supporting the same feature set yet, if you do, let me know, that would greatly simplify testing. For now I build a separate generic x86_64 build so I can test it in a VM, before deploying it.
I know this is not recommended, as it can trigger errors in target system now and then and is mostly untested.
Under my system, advanced configuration are empty:
--- Advanced configuration options (for developers)
How can access Advanced configuration options?