Earlier this week IBM announced the z17 mainframes powered by Tellum I processors . But months prior we've seen IBM patches for an "arch15" target for SystemZ within the open-source compilers that we expected was z17. IBM has now confirmed such and has begun updating the open-source compilers to acknowledge this z17 compiler support.

With prior IBM SystemZ generations we've seen the same move of them publishing their open-source compiler support early and then post-launch go about actually acknowledging the product they are targeting. IBM also does this over on the POWER side too where they post "future" compiler patches and then post-launch rename "future" to their next-gen product name/number. While less than straightforward, it's at least a better solution than waiting until post-launch for the CPUs before introducing any level of compiler support.

Yesterday the LLVM Clang 21 Git code was updated now to recognize "z17" rather than having to go the "arch15" route for targeting the new IBM z17 hardware shipping this summer. There's also a scheduler description added and we'll see if they add any more z17 compiler refinements ahead of the next-gen hardware shipping this summer.

This patch is what now formally acknowledges the z17 support within the open-source LLVM compiler.