AMD Publishes More Zen 3 Compiler Support Patches For LLVM
Last month AMD engineers began posting their "znver3" support for LLVM that was largely replicating the existing Znver2 (Zen 2) target and exposing the newly-enabled instructions. Fortunately, now through the holidays, further work is coming for LLVM and presumably GCC in time.
Under review today is the Zen 3 scheduler descriptions for LLVM.
Merged last week meanwhile was this addition for exposing the TLBSYNC, INVLPGB, and SNP instructions found with Zen 3 processors.
The Zen 3 progress for LLVM can be tracked via reviews.llvm.org.
This work should ultimately make it into LLVM 12.0, which will be out around March -- though unfortunate it's taken until months after the Ryzen 5000 series premiered as the first Zen 3 processors until seeing optimized support in the compilers for those wishing to enjoy the performance benefits of -march=znver3. As the Zen 3 support continues to mature in both the GCC and LLVM Clang compilers there will be more optimization benchmarks on Phoronix but for now there are the Ryzen 9 5950X compiler benchmarks with various optimization settings from a few days ago.