Daniel Lemire's blog

AI-assisted programming is fast evolving and there is a tension between 'we no longer need to understand the code' and 'what is my purpose as a programmer'. I recorded a short video on this topic with how I think the tension can result in conflicts.

When a compiler optimizes your program, it has to guess. Which functions are worth inlining? Which side of a branch is the common one? Which method does this interface call actually reach? At compile time it cannot know, so it uses heuristics. Profile-gui

C++26 adds a new container to the standard library: std::hive. It is meant to occupy the ground between std::vector and std::list. Like a vector, it keeps its elements in contiguous blocks of memory, so scanning it does not require you to chase a pointer

When your program asks for memory that is not in cache, the processor has to go to RAM. That trip costs on the order of 100 nanoseconds. On a 3 GHz core, that is about 300 cycles of doing nothing. Memory latency has not improved in ten years. The 2016 Bro

Every week, I discuss with people who want to get a PhD. For years, I have been advising people not to pursue a PhD. It may come as a surprise to some. You would expect people with a PhD to earn more money. Individuals who complete doctorates tend to have

In 1945, Vannevar Bush published a report entitled Science: The Endless Frontier. His thesis was that prosperity follows from basic research. The report was highly influential in the United States and elsewhere. It led to the creation of an entirely new g

A few years ago, a friend of mine was stuck. He needed to quickly process over a hundred high-quality images according to a complicated sequence. He was using Photoshop, but it was going to take him days. Initially, he asked for my help, could I do the ma

I have been on X for a long time. Like most people who post regularly, I have a gut feeling for what might interest people. I post in the morning. Longer posts seem to do better. But gut feelings are not measurements. And until recently, digging into your

When I was a kid, most people did not know how to type. We took typing class. The final exam was a speed test: words per minute. Today, you will not impress anyone by saying you can type. In fact, cursive writing is fading. Kids increasingly cannot read o

Suppose that you have a configuration file in JSON. Something like this: { "width": 1920, "height": 1080, "fullscreen": true, "title": "My Game", "volume": 0.8 } Normally you ship this file alongside your program, open it at startup, read it, and parse it