1870486 - WASM demo (https://www.fxhash.xyz/generative/28947) is slower in Nightly compared to Chrome

Status: NEW

(Core :: JavaScript: WebAssembly, task, P3)

Description

[Mayank Bansal]

Go to https://www.fxhash.xyz/generative/28947
Click on run

Nightly: https://share.firefox.dev/3NSNbqf (4.5s)
Chrome: https://share.firefox.dev/3TuZHji (3s)

Comment 1

[Mayank Bansal]

Attachment: about:support

Comment 2

[Yury Delendik (:yury)]

Two things here:

• The profiler shows that entire thing is run in one function $main::art::h55a937f259a0de0d, so tiering is not working here and it never reaches the Ion
• The HTTP caching is not working since the code is loaded via data:application/wasm;charset=utf-8;base64,AGFzb... URL

The calculation kicks in immediately and not giving a change for Ion to execute and there is no caching ability. The size of the Wasm is 1.5MB. It works fast when run with baseline disabled.

It is easy to address the issue for the application by loading Wasm via instantiateStream from HTTP resource and/or load it before the "run" button is clicked.

Comment 3

[Mayank Bansal]

Profile with latest Nightly: https://share.firefox.dev/3wYDKjn