SIMD Parser Speedups Explained

So the plan is to use SIMD intrinsics to scan 16–64 bytes at a time, generating bitmasks for “interesting” characters (e.g. letters, punctuation, whitespace) and feeding those directly into the FST transitions. They do this in high-speed JSON and HTML parsers, it should slash branch mispredictions and data dependencies, yielding large speedups in practice.

A person explains an extremely technical optimization involving SIMD, bitmasks, FST transitions, and JSON/HTML parsers to a woman who appears visibly uninterested. The joke is the mismatch between dense computer-science jargon and the casual social setting, making it useful as a reaction to overly complicated technical explanations.

• @profunctor_io / 10899 2025-05-18