1536358 - Prototype using PLS for clip task rendering on mobile devices with WR

Status: RESOLVED WONTFIX

(Core :: Graphics: WebRender, enhancement, P2)

Description

[Glenn Watson [:gw]]

Using pixel local storage on supported devices seems like a perfect feature for clip mask rendering in WR. This has the potential to drastically reduce resolve bandwidth, and texture fetch bandwidth.

Comment 1

[Glenn Watson [:gw]]

Attachment: 0001-WIP-Use-pixel-local-storage-for-clip-masks.patch

This patch contains a prototype of using pixel local storage for clip masks. It's incomplete, but has enough functionality to do benchmarking.

Unfortunately, it seems slower than the existing code on my test cases. This is surprising, since the memory resolve bandwidth should be much better.

I'm going to leave it here as a WIP patch for now, and revisit again in the near future.

It's possible that there are some mistakes in the patch, or some slow path that is being hit unexpectedly. It's also possible that in the test case I'm using the extra copy bandwidth is not relevant, but that it may be relevant in more real world cases.

Comment 2

[Glenn Watson [:gw]]

Unassigning for now, since I'm not planning to work on this in the near future.