Coding Neon Kernels for the Cortex-A53

(destevez.net)

18 points | by yeko 9 hours ago ago

8 comments

  • dmitrygr 7 hours ago ago

    A53 is not a great core, and seemingly no compiler targets it well. Back at el goog, ChromeOS team had an intern who used a cycle-accurate model of it to find that android's AOT compiler produced shit code for it when multiplies were involved. A small patch to the AOT compiler produced measurable perf improvement in most android workloads on A53, costing no perf on A57/A72. This patch was, of course, not shipped (politics).

    • BoingBoomTschak 7 hours ago ago

      Could you expand on the "politics" part? I can't imagine the reason why. I mean, if you had said "suits thought this wasn't business relevant" or something, I'd have believed it.

      • dmitrygr 7 hours ago ago

        The intern was in the ChromeOS team, the fix would have needed to go into android. Those two teams were always in a bit of "stay in your lane, buddy" relationship.

        • saagarjha 6 hours ago ago

          I continue to maintain that Google should adopt negative peer bonuses

          • mtklein 6 hours ago ago

            "The peer malus" - Frederic Beal

          • gessha 5 hours ago ago

            And that will result increased tension between the teams “downvoting each other”.

            Maybe this way Google will truly become a Microsoft-type of company.

        • jjmarr 5 hours ago ago

          I thought the fabled monorepo was supposed to prevent this?

          • nullpoint420 5 hours ago ago

            IIRC, both Android and Chrome(OS) upstream are not in the google3 monorepo.