highway VS jxl.js

The bf16 dot instruction replaces 6 instructions: https://github.com/google/highway/blob/master/hwy/ops/x86_12...

[0] for those interested in Highway.

It's also mentioned in [1], which starts off

> Today we're sharing open source code that can sort arrays of numbers about ten times as fast as the C++ std::sort, and outperforms state of the art architecture-specific algorithms, while being portable across all modern CPU architectures. Below we discuss how we achieved this.

[0] https://github.com/google/highway

[1] https://opensource.googleblog.com/2022/06/Vectorized%20and%2..., which has an associated paper at https://arxiv.org/pdf/2205.05982.pdf.

Thanks so much!

Everyone working on this self-selected into contributing, so I think of it less as my team than ... a team?

Specifically want to call out: Jan Wassenberg (author of https://github.com/google/highway) and I started gemma.cpp as a small project just a few months ago + Phil Culliton, Dan Zheng, and Paul Chang + of course the GDM Gemma team.

C++ users can enjoy Highway [1].

[1] https://github.com/google/highway/

At that point it is better to have some kind of DSL that should not be in the main language, because it would target a much lower level than a typical program. The best effort I've seen in this scene was Google's Highway [1] (not to be confused with HighwayHash) and I even once attempted to recreate it in Rust, but it is still distanced from my ideal.

[1] https://github.com/google/highway

Interesting, thanks for sharing :)

At the time we open-sourced Highway, the standardization process had already started and there were some discussions.

I'm curious why stdlib is the only path you see to default? Compare the activity level of https://github.com/VcDevel/std-simd vs https://github.com/google/highway. As to open-source usage, after years of std::experimental, I see <200 search hits [1], vs >400 for Highway [2], even after excluding several library users.

But that aside, I'm not convinced standardization is the best path for a SIMD library. We and external users extend Highway on a weekly basis as new use cases arise. What if we deferred those changes to 3-monthly meetings, or had to wait for one meeting per WD, CD, (FCD), DIS, (FDIS) stage before it's standardized? Standardization seems more useful for rarely-changing things.

1: https://sourcegraph.com/search?q=context:global+std::experim...

2: https://sourcegraph.com/search?q=context:global+HWY_NAMESPAC...

Thanks for the link. We were previously using GFNI for bit reversal and 8-bit shifts, and I just extended that to our 8-bit BroadcastSignBit (https://github.com/google/highway/pull/1784).

You could study Google's Highway library [1].

[1] https://github.com/google/highway

Runtime feature detection need not be rare nor hard, it's a few dozen lines of boilerplate. You can even write your code just once: see https://github.com/google/highway#examples.

> It's so frustrating how the chromium team is ending up as a gatekeeper of the Internet by pick and choosing what gets developed or not.

https://github.com/niutech/jxl.js is based on Chromium tech (Squoosh from GoogleChromeLabs) and provides an opportunity to use JXL with no practical way for Chromium folks to intervene.

Even if that's a suboptimal solution, JXL's benefits supposedly should outweight the cost of integrating that, and yet I haven't seen actual JXL users running to that in droves.

So JXL might not be a good support for your theory: where people could do they still don't. Maybe the format isn't actually that important, it's just a popular meme to rehash.

https://github.com/niutech/jxl.js a javascript polyfill taken from the main page https://jpegxl.info/

There are other decoders [0] written in a "safe language" (rust) listed as well. So no there are many "safe" implementations

[0] https://github.com/tirr-c/jxl-oxide

> If you care about JXL, and only want to support JXL, and you put a JXL in your picture tag, then the browser still won't render it, even if you use a picture tag.

Is this true if you provide a polyfill? Have you tried it and it failed? (Serious question.)

https://github.com/niutech/jxl.js

All of the people here who are so passionate about JPEG-XL will be happy to learn that there's nothing preventing them from using it on their sites right now:

https://github.com/niutech/jxl.js

If you want Chrome to ship with JPEG-XL support, use it. At some point, browser makers will decide it's worth the cost to them and all users to add it.

> Please be aware that some images may not load on this page unless your browser supports JPEG-XL

The site could provide a WebAssembly decoder to make the JPEG-XL images work for everyone.

For example, here's a WebAssembly decoder: https://github.com/niutech/jxl.js

Demo: https://niutech.github.io/jxl.js/

at this point, I'd consider just using a polyfill library to decode jpegxl data client-side, like JXL https://github.com/niutech/jxl.js

:) There are some wasm vs native benchmarks in the context of JPEG XL (for example https://github.com/niutech/jxl.js#benchmark)

For adding JPEG XL support I went with jxl.js which I modified for my use case. After looking through the main file, which is also called jxl.js, I decided I only needed 2 relevant code blocks. The one to decode the image and the one to turn the ImageData into something I could display in my existing codebase (which I already partially had implemented for another use case).

It's easy - you'll get ReferenceError: SharedArrayBuffer is not defined when the COOP and COEP headers are not set. Multithreading is enabled by default if you use the scripts from multithread folder. If only SIMD is supported, it is being used. Oh, and progressive decoding is also enabled by default.