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I wonder too what happens when all the human workers are out of the job and out of practice, and every company is dependent on a handful of dominant AI companies for their workforce. You'd think businesspeople would understand the concept of a captive market but apparently they're too busy salivating over the prospect of laying people off.

There isn't a language that achieves C's performance, access to hardware and portability while also having superior syntax. The reason C is hard is because it makes sacrifices to enable the above. A Rust (for example) compiler targeting many microcontrollers (8/16-bit word size (not all), Harvard architectures like AVR, non-8-bit byte) simply can't be written due to assumptions made by the spec. Many such architectures are still in use.

This is interesting. I wonder who the "other allocator" was. I think this would benefit from direct comparison with jemalloc, glibc and others. It would also be interesting to observe the effects of different "page" sizes (a better name than "pages" wouldn't go amiss either).

The developers of each have engaged in a few flamewars and the commenter I replied to was critical of GrapheneOS using similar language, so I made a (tongue in cheek comment) implying the commenter was starting the flamewar back up

Is the CalyxOS Vs GrapheneOS shitflinging about to start up again?

Fair point that binary search causes a lot of branch mispredictions. Did you ever measure whether the unrolled linear search with 8 elements outperforms a "rolled" one? Because with instruction level parallelism I wonder how much difference removing 8 mostly easily predicted (in the linear search) branches makes.

Interesting, thanks for sharing. I actually assumed ?: desugared to an if-else and never checked. I was a bit confused by the if-else chains you have e.g. on line 111 where it looks like you could just use the else branch for every case?

You could circumvent the counter issue by pinning to a specific core, otherwise you'd have to use scheduler events (ftrace/perf on Linux) to know which CPU you were running on at specific times and when so you could subtract the right counters (I've had to do this before and it isn't pretty). It would also prevent issues where your task gets preempted and moved to another core and you have to warm the caches again. If you use Linux, options like isolcpus and nohz_full ensure you're not measuring the scheduler/other tasks but have to be set at boot. But if your loops between clock_gettime take substantially more than clock_gettime itself then at least the timer overhead is probably not that important.

As for the branch prediction, I would think most of the branches would be predicted correctly because usually you'll have runs of "not x" before each "is x". Switching between many loops of course hurts the prediction.

My SIMD knowledge only extends as far as which compiler options make my code faster.

No shame using LLMs, I use them extensively, but I find I have to write some code yourself because I make noticeably more mistakes coding if I have let the LLM do everything for a couple of weeks.

How did you do it? Hopefully you generated thousands of such arrays and measured the cost of searching all of them as a single iteration? Because depending on what you use to measure time, the overhead of reading the timer would likely dwarf the cost of searching such a small array. The best case is a dedicated cycle counter instruction/register (e.g. rdtsc) and even that may cost hundreds of cycles. Cache hits cost less than a cycle so if your timing code gated a small number of searches you essentially didn't measure the search at all.

That aside your findings point to the prefetcher having identified your linear searches as sequential access so practically every single access was a cache hit (you effectively measured the latency between a CPU and its L1 cache). If you wanted to test this you could do something like make each element some number of cache lines wide. Stream prefetchers have a maximum stride, so variables more than that many bytes apart won't be prefetched. Google's multichase benchmark uses 256 bytes IIRC.

I'm guessing you don't really do this for users since the response for all of them should be 401 on any user that you aren't logged in as? I would argue even for IDs that don't exist, you should get the same error whether they don't exist or you just aren't authorised to see them. It's been a few years since I worked in web but I think that's what I would have done, GitHub does similar for private repos.

What does it do for you that, say, konsole, gnome-terminal or even xterm wouldn't?

Why are people using "learnings" as a word, when "lessons" already fits all its use cases? It's quite jarring.

Considering they knew these failure modes in advance, would it not have been prudent to put some sort of self-righting mechanism on the lander? Something like the mechanical arms you see in Robot Wars.