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Comment by SoSKatan | Hacker News Reader

I've written my fare share of performant code over the years, but this is some next level shit. I've been reading it the last few hours. The only question I have is what is the term for that place considered two degrees past black magic? Since you live there, I have to assume you know the name.

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It's not magic. The things that enable writing this kind of code are essentially practice and specialization. Most people have to write code that works all all architectures and where performance is probably less critical than having a simple, workable codebase - so the opportunities to practice writing SIMD code are rare under those constraints.

Unfortunately, the fragmentation of SIMD standards and various pitfalls in implementation (the much ballyhoo'ed "running AVX will make your processor clock to half its speed or something" exaggerations, for example) make a lot of people nervous about putting in the time to commit to developing expertise, which is a shame.

Not really a question, but if you ever get to the point of wondering what a good next challenging project would be, consider generalizing some of these techniques into a next generation Yacc / Bison replacement.

Something that can take generic grammer rules and turn it into a high performance parsing engine.

It wouldn't have to support every possible grammar or option. Json isn't that complex of a language, but even a limited set of grammar options in exchange for a performant parser could be of benefit for a very large set of problems.

Oh now that would be an interesting tool

It's on the list as a research project. It's not obvious to me at this stage that the bottlenecks for more advanced parsers are necessarily going to be in the same place as they are for JSON. It might make more sense to look at a state-of-the-art parser and see if we can contribute a few tricks instead.

That sounds interesting. Where is the best place to follow your future work? Your & Daniel Lemire's Github, or elsewhere?

I might go so far as to post to branchfree.org, and Daniel posts at https://lemire.me/blog/ so either of those, plus github, ought to cover it.

I'm just starting to look at Tree-sitter; that might qualify as a state of the art parser that could use a few tricks.

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