Make the storage used to accumulate the RGB sums and the Y histogram
value a vector of SwIspStats objects instead of a single object so
that when using multi-threading every thread can use its own storage to
collect intermediate stats to avoid cache-line bouncing.
Benchmarking with the GPU-ISP which does separate swstats benchmarking,
on the Arduino Uno-Q which has a weak CPU which is good for performance
testing, shows 20ms to generate stats for a 3272x2464 frame both before
and after this change.
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
6e53e72e96