Invert loops to operate vertically in the inner loop. This allows
removing redundant loads.
Also add preloading of data.
Change-Id: I4fa85c0ab1735bcb1dd6ea58937efac949172bdc
Each iteration of the horizontal loop reuses 7 of the 11 source
values. Loading only the 4 new values saves some time.
Also add preload for source data.
Overall 4% faster on Chromebook.
Change-Id: I8f69e749f2b7f79e9734620dcee51dbfcd716b44
Loading to single lanes in multiple registers is expensive since
it requires a read and write of each register which saturates
the register file access. Loading to single registers followed
by a separate transpose reduces this pressure.
Change-Id: I4cc35887ddbca80e5e635b50d2b1d158de9668ee
Independent horizontal and vertical implementations.
Requires that blocks be built from 4x4 and [xy]_step_q4 == 16
6-10% improvement. CIF improved the least.
Change-Id: I137f5ceae4440adc0960bf88e4453e55a618bcda
