commit 5236846b648418089d9d88b797ed1b7a5e03e907
author George Steed <george.steed@arm.com> Wed Apr 24 18:03:20 2024 +0100
committer Frank Barchard <fbarchard@chromium.org> Mon Jul 08 20:26:23 2024 +0000
tree d20ee38ffb791cc072142d2e1c25918460ab2c7e
parent 555f80f3ce4b789f4e91e98e0848c3d8f51d19ef

[AArch64] Keep UV interleaved in some *ToARGBRow_SVE2 kernels

The existing I4XXTORGB_SVE macro operates only on even byte lanes of the
loaded U/V vectors. This is sub-optimal since we are effectively wasting
half of the vector in any pre-processing steps before the conversion.
In particular, where the UV components are loaded from interleaved data
we can save a TBL instruction by maintaining the interleaved format.

This commit introduces a new NVTORGB_SVE macro to handle the case where
U/V components are interleaved into even/odd bytes of a vector,
mirroring a similar macro in the AArch64 Neon implementation.

Reduction in runtimes observed compared to the existing SVE2 code:

                   | Cortex-A510 | Cortex-A720 | Cortex-X2
NV12ToARGBRow_SVE2 |       -5.3% |       -0.2% |     -4.4%
NV21ToARGBRow_SVE2 |       -5.3% |       -0.2% |     -4.4%
UYVYToARGBRow_SVE2 |       -5.6% |        0.0% |     -4.6%
YUY2ToARGBRow_SVE2 |       -5.5% |       -0.1% |     -4.2%

Bug: libyuv:973
Change-Id: I418de2e684e0b6b0b9e41c39b564438531e44671
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5622133
Reviewed-by: Justin Green <greenjustin@google.com>
Reviewed-by: Frank Barchard <fbarchard@chromium.org>