commit d5303f4f779a6baf66bbac8a97937e507ffaaaba
author George Steed <george.steed@arm.com> Mon Apr 22 09:03:28 2024
committer Frank Barchard <fbarchard@chromium.org> Mon Sep 16 04:36:43 2024
tree 5a90ee5285e107ec34ae4feca7a931e4ce0cef8b
parent 772f0fde1c6f5dbdd741b8c79e626a97304ebc7e

[AArch64] Unroll ARGB1555ToARGBRow_NEON to use full Neon vectors

Processing more data per loop iteration means that we can use the full
128-bit Neon vectors and also allows us to use e.g. UZP1 to perform XTN
+ XTN2 in a single instruction.

The early Cortex-X cores are not a fan of ST4 .16b with a
post-increment, so split out the pointer increment to a separate
instruction to avoid this bottleneck.

Reductions in runtime observed for ARGB1555ToARGBRow_NEON:

 Cortex-A55: -18.1%
Cortex-A510: -11.2%
Cortex-A520: -39.5%
 Cortex-A76: -18.0%
Cortex-A715: -34.8%
Cortex-A720: -34.8%
  Cortex-X1:  -0.9%
  Cortex-X2:  -4.6%
  Cortex-X3:  -3.6%
  Cortex-X4: -20.8%

Bug: libyuv:976
Change-Id: Iae2ac24ffdbc718cd1e05bb77191f8d1df3fcf6f
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/5790975
Reviewed-by: Frank Barchard <fbarchard@chromium.org>
Reviewed-by: Justin Green <greenjustin@google.com>