WebAssembly (Wasm)

[SolidComp]

Hi all — Have any of you experimented with WebAssembly (Wasm)? It's an interesting high-performance binary compilation target for web browsers, with better than JS performance. I think there are compilers for C, C++, Rust, Typescript, Go, and a few other languages, though I'm not sure about their maturity. The C/C++ compiler seems most mature.

Wasm applications run in a virtual stack machine, with static types. It's not meant to be programmed in directly, but rather is a compilation target for other PLs. Wasm's text representation looks like s-expressions.

Are there any compression benchmarks that include Wasm implementations? I haven't seen anything so far.

It looks like a good way for web apps and games to use compression codecs other than gzip and brotli – codecs that aren't built into browsers yet, like Zstd, Kraken, etc. Wasm is supported by all major browsers: Edge, Chrome, Firefox, Safari, and Opera.

Homepage: https://webassembly.org/

MDN: https://developer.mozilla.org/en-US/docs/WebAssembly

[Cyan]

I've tested wasm compilation target some time ago with both lz4 and zstd.

I found the performance to be surprisingly good.
In "good" cases, it was only ~10% slower than native 32-bit code.
In "worse" cases, it was up to 2x slower.
Most of the times, outcome will be between those 2 extremes, which I believe is still very good.

On the minus side, vector instructions did not work (documentation hints that it should or will be present, but I was not so lucky in my tests).
Also, as the address space is 32-bit, it can force some code to use a 32-bit code path.
The impact is especially sensible for `zstd`, since its 64-bit variant is substantially faster.

Anyway, not magical, but definitely functional, and already good enough in the performance department.
I agree it opens new possibilities.

As a follow-up example, `zstd` repository now hosts a script from Carl Woffenden
which converts the `libzstd` library into a single source file, then compile and test it in `wasm` mode :
https://github.com/facebook/zstd/tre..._libs/examples

[Hakan Abbas]

Below is an interesting video filter test. (WASM vs JS)

https://d2jta7o2zej4pf.cloudfront.net/