Fine-grained Locking with Two-Bit Mutexes
Lets say you want to have a mutex for every item in a list with 10k elements. It feels a bit wasteful to use a std::mutex for each of those elements. In Linux std::mutex is 40 bytes, in Windows it’s...
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Beautiful Branchless Binary Search
I read a blog post by Alex Muscar, “Beautiful Binary Search in D“. It describes a binary search called “Shar’s algorithm”. I’d never heard of it and it’s impossible to google, but looking at the...
View ArticleTwo Kids Put Me on a Two Sleep Schedule
I’m writing this at 2am, having already slept from 9pm to 1am. I will sleep again from 4am to 7am. This is apparently called “biphasic sleep”, which I first heard about in the 2022 article The...
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Transform Matrices are Great and You Should Understand Them
The title of this blog post is obvious for any game programmer, but I notice that people outside of games often write clumsy code because they don’t know how transform matrices work. Especially when...
View ArticleHow I use LLMs to program
Studies have shown that LLMs help novice programmers more than experienced programmers. This matches my experience. At work I see that interns or new hires have some LLM window open almost all the...
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Initial CUDA Performance Surprises
I am somehow very late to learning CUDA. I didn’t even know until recently that CUDA is just C++ with a small amount of extra stuff. If I had known that there is so little friction to learning it, I...
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Why Does Integer Addition Approximate Float Multiplication?
Here is a rough approximation of float multiplication (source): float rough_float_multiply(float a, float b) { constexpr uint32_t bias = 0x3f76d000; return...
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I’m Open-Sourcing my Custom Benchmark GUI
I think one of the reasons why I was able to do good performance work over the years is that at some point I started taking benchmarking seriously enough to write my own library. I used to use Google...
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Revisiting Knuth’s “Premature Optimization” Paper
The most famous quote from Knuth’s paper “Structured Programming with go to Statements” is this: There is no doubt that the grail of efficiency leads to abuse. Programmers waste enormous amounts of...
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Installing a Mini-Split AC in a Brooklyn Apartment
Last year, 2024, we replaced four PTACs with a mini-split AC. I’ve been asked about it often enough (by neighbors, coworkers, friends) that I decided to write up the experience. Hopefully it’s useful...
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