tree d1f5d79aa5ee66ff82e81ea00f7895b81f7c19fe
parent ce3b001c886dc788bad36cb95ddcef4556bb62c5
author Jonathan Wright <jonathan.wright@arm.com> 1658252138 +0100
committer James Zern <jzern@google.com> 1662604442 +0000

Specialize Neon subpel variance by filter value for large blocks

The optimal implementation of the bilinear interpolation depends on
the filter values being used. For both horizontal and vertical
interpolation this can simplify to just taking the source values, or
averaging the source and reference values - which can be computed
more easily than a bilinear interpolation with arbitrary filter
values.

This patch introduces tests to find the most optimal bilinear
interpolation implementation based on the filter values being used.
This new specialization is only used for larger block sizes
(>= 16x16) as we need to be doing enough work to make the cost of
finding the optimal implementation worth it.

Change-Id: Ie3dd99093fde19ee9abf3233e1c828c97510b464