purplesyringa's blog
purplesyringa's blog
Alisa Sireneva
Hi! 👋 I'm Alisa Sireneva (she/her), a software developer and blogger from Moscow. I specialize in performance optimization and systems programming. I also have experience with security, compression, and decentralized systems. My primary goal as a writer is to teach the concepts I regularly apply through accessible content.
Latest Posts
I’m making progress on the Java decompiler I’ve mentioned in a previous post, and I want to share the next couple of tricks I’m using to speed it up. Java bytecode is a stack-based language, and so data flow is a bit cursed, especially...
This post is about a popular but niche technique I can never find a succinct reference for. I didn’t invent it, I just need a page I can link when giving optimization advice. Integer ↔ float casts that utilize specialized processor...
I’m working on a Java decompiler because I’m not satisfied with the performance of other solutions. I’ve always heard that decompiling JVM bytecode is a solved problem, but I’ve concluded that the decompilation methods used by CFR and...
I’m not talking about skill, knowledge, or convincing a world focused on radical acceleration that optimization is necessary. Performance optimization is hard because it’s fundamentally a brute-force task, and there’s nothing you can do...
Null pointers look simple on the surface, and that’s why they’re so dangerous. As compiler optimizations, intuitive but incorrect simplifications, and platform-specific quirks have piled on, the odds of making a wrong assumption have...
The RAM myth is a belief that modern computer memory resembles perfect random-access memory. Cache is seen as an optimization for small data: if it fits in L2, it’s going to be processed faster; if it doesn’t, there’s nothing we can do....
In languages like Python, Java, or C++, values are hashed by calling a “hash me” method on them, implemented by the type author. This fixed-hash size is then immediately used by the hash table or what have you. This design suffers from...
If you don’t take whitespace into account. My friend challenged me to find the shortest solution to a certain Leetcode-style problem in Python. They were generous enough to let me use whitespace for free, so that the code stays readable....
Four days ago, the Rust Foundation released a new draft of the Rust Language Trademark Policy. The previous draft caused division within the community several years ago, prompting its retraction with the aim of creating a new, milder...
Three months ago, I wrote about why you might want to use panics for error handling. Even though it’s a catchy title, panics are hardly suited for this goal, even if you try to hack around with macros and libraries. The real star is the...
Demoscene is the art of pushing computers to perform tasks they weren’t designed to handle. One recurring theme in demoscene is the shadow-art animation “Bad Apple!!”. We’ve played it on the Commodore 64, Vectrex (a unique game console...
Коллизии в играх обнаруживаются тяжелыми алгоритмами. Для примера попробуйте представить себе, насколько сложно это для просто двух произвольно повернутых кубов в пространстве. Они могут контактировать двумя ребрами, вершиной и гранью...
I want to provide a smooth experience to my site visitors, so I work on accessibility and ensure it works without JavaScript enabled. I care about page load time because some pages contain large illustrations, so I minify my HTML. But...
Developers don’t usually divide numbers all the time, but hashmaps often need to compute remainders modulo a prime. Hashmaps are really common, so fast division is useful. For instance, rolling hashes might compute u128 % u64 with a...
I have recently done some performance work and realized that reading about my experience could be entertaining. Teaching to think is just as important as teaching to code, but this is seldom done; I think something I’ve done last month...