GCC 12 Lands Support For -march=armv9-a

As of this morning the GCC 12 compiler has landed support for -march=armv9-a for targeting the forthcoming Armv9-A ISA.

After announcing ARMv9 earlier this year and the likes of the Cortex-X2, the open-source code compilers has been preparing for this evolutionary advancement over ARMv8.

LLVM/Clang has been working on Armv9-A enablement and the GNU toolchain from Binutils to the GNU Compiler Collection have also been preparing their new code. As of today GCC 12 hit the stage of being able to target -march=armv9-a as of this commit. Using "-march=armv9-a" is used for targeting the ARMv9-A ISA and enabling the new instructions available. Tuning is currently based on the existing ARMv8 Cortex-A53. This is an important step for supporting the next-gen Arm architecture.

GCC 12.1 as the first stable GCC 12 release should be out in Q2'2022. Feature development is beginning to wind down on GCC 12 to focus on bug fixing but given the risk of regression is low it's still possible we'll see more ARMv9 feature work land before next year's release.