HN.zip

Coding Neon Kernels for the Cortex-A53

9 points by yeko - 5 comments
dmitrygr [3 hidden]5 mins 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 [3 hidden]5 mins 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 [3 hidden]5 mins 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 [3 hidden]5 mins ago
I continue to maintain that Google should adopt negative peer bonuses
mtklein [3 hidden]5 mins ago
"The peer malus" - Frederic Beal