1) "Who cares" is not the sort of thing you want to say to someone who cares about performance because:

2) Sending the data to buffers for subsequent reduction was the first implementation (2009). But it was a memory hog and a 5% or so slowdown to perform the reduction subsequently rather than concurrently with Atomic Ops and 64-bit Fixed Point (2012).

But I guess what we're arriving at is that this is essentially a functional design using imperative code? I can live with that.