Hacker News: AlotOfReading

New comment by AlotOfReading in "A 3rd World Embedded Engineer Responds to "RISC-V They Should Have Known Better""

AlotOfReading — Mon, 17 Aug 2026 00:26:29 +0000

5 years ago was Apple M1/M2 and AMD Zen 3. What RISC-V cores are remotely competitive with that?

New comment by AlotOfReading in "The Case Against Formal Verification, 50 Years Later"

AlotOfReading — Sun, 16 Aug 2026 21:22:41 +0000

The final proof you get from formal methods is often irrelevant in my opinion. Most of the benefit comes from architecting the system so as much as possible can be verified and forcing yourself to make intentional decisions on the edge cases. The results are for other people.

I'm not sure you want to create a record of intentional decisions if you're at Facebook though.

New comment by AlotOfReading in "A third world engineer responds to “RISC-V: They should have known better”"

AlotOfReading — Sun, 16 Aug 2026 20:44:35 +0000

Haven't seen anyone sending partiful invites here.

New comment by AlotOfReading in "What happens when an LLM never sees material beyond fifth grade?"

AlotOfReading — Sun, 16 Aug 2026 14:08:34 +0000

    For example poor people who have never thought about rising out of it...

I obviously don't have numbers on this, but I strongly doubt there's a poor person on this planet who's never thought about "rising" out of it. That's the dream the lottery sells, that's why so many kids want to be basketball stars / celebrities / influencers, etc.

My personal experience is that the required difficulties of my life have decreased in direct proportion to my income, leaving mainly the self-imposed difficulties. It's not hard to extrapolate that line a little further to billionaires.

New comment by AlotOfReading in "Guiding Ships with Moire Patterns (2018)"

AlotOfReading — Sun, 16 Aug 2026 05:17:35 +0000

You can probably get better angular resolution with lenticular sheets. You see one image if you're dead on, and the other images if you're off to the left or right.

Some napkin math says a couple inches of precision should be achievable at reasonable distances?

New comment by AlotOfReading in "RISC-V: They Should Have Known Better"

AlotOfReading — Sun, 16 Aug 2026 00:57:55 +0000

Then it crashes in a nice, obvious way as soon as you execute one of them? Illegal instructions aren't usually that hard to debug unless they're related to memory safety issues.

New comment by AlotOfReading in "RISC-V: They Should Have Known Better"

AlotOfReading — Sat, 15 Aug 2026 20:33:47 +0000

     Either you're writing embedded firmware and know exactly what core you're using, or you're writing an application that runs in an operating system and that system has a minimum ABI like RVA20 or whatever.

It's very common for embedded teams these days to support a diverse set of cores with a shared codebase, depending on the specific requirements of different products/systems. SoC vendors will often change cores between versions or product lines, and I might need performance in this one system vs specific interfaces in another. So even if I know what core I'm using today, I don't know what core I'll be using in a year or five. I may also be writing a library or other reusable component and have no idea what core will run things today.

    Array accesses take an extra instruction? Either you're in a tight loop walking a tiny array and you don't do the full offset calculation per step, or you're walking over an array in RAM and you're bottlenecked by the memory bus.

Let's take the bitfield instructions the author complains about for similar reasons. If bfi/bfx takes multiple instructions, optimal structure packing isn't necessarily a win for performance or memory usage. The programmer needs to trade off how often the structure is instantiated vs accessed. Even they can make the right decision today, it might not be the right decision tomorrow. And if they get it wrong, that might not be apparent until later (when it will be somewhat obscured in superficial memory usage analysis). Or the ISA can get it right the first time and also make things easier for compilers/humans in the process.

    "Who can predict how their binary will act when a floating point store silently becomes a double-register move or a jump instruction, or vice-versa?" - THIS DOES NOT HAPPEN IN PRACTICE.

I can easily imagine this happening. When you change embedded platforms, the typical approach is to take the existing system and compile it for the new platform without carefully revisiting every decision made in the old system. If one of your vendor blobs was specified for the old system and the new system is "similar", you'll just link it in and see what happens. The metadata in the blob will hopefully catch the issue at link time, but it was an avoidable error.

New comment by AlotOfReading in "RayforceDB – a pure C analytics database with a Lisp-like syntax"

AlotOfReading — Fri, 14 Aug 2026 17:25:20 +0000

It's a little weird to truncate the history [0] of your open source project and lock the v1 commits in a separate repo with limited access [1]. Are the authors embarrassed of the commit history?

[0] https://github.com/RayforceDB/rayforce/pull/166

[1] https://github.com/RayforceDB/rayforce2/blob/master/README.m...

New comment by AlotOfReading in "NP-overrated"

AlotOfReading — Thu, 13 Aug 2026 23:42:19 +0000

The description you've given for apt just sounds almost exactly like SAT, a problem that's very efficiently approximated. That's exactly how the --solver 3.0 flag on recent apt versions works [0].

[0] https://blog.jak-linux.org/2024/05/14/solver3/

New comment by AlotOfReading in "Understanding is the new bottleneck"

AlotOfReading — Thu, 13 Aug 2026 23:11:47 +0000

The challenge of hard rules like this is that they're always overly restrictive. I've made multi-thousand file PRs that needed two lines of description including the title, and 5 line PRs that needed a 1hr presentation to fully explain them.

My personal guideline is that writing for humans should be done by humans.

New comment by AlotOfReading in "Antiqua–Fraktur dispute"

AlotOfReading — Thu, 13 Aug 2026 13:46:12 +0000

Part of the point was to hand out copies to wealthy allies as a visible sign of favor. Physical arches are a little bit harder to dole out that way, or distribute around the nation. It was also cutting edge technology in a way simple arches weren't.

New comment by AlotOfReading in "Tailscale Traces Database Corruption to 16y/o SQLite WAL-Reset Bug"

AlotOfReading — Wed, 12 Aug 2026 16:12:48 +0000

The general answer to this is Byzantine consensus, which cryptocurrency blockchains are designed to solve. If your nodes are willing to fail a little more politely (e.g. no lying, immediately crashing, etc) you can use something cheaper like raft/paxos.

But yeah, it's a lot cheaper to build a reliable system than it is to be resilient.

New comment by AlotOfReading in "CFTC declares market emergency, orders Kalshi to continue to operate in New York"

AlotOfReading — Wed, 12 Aug 2026 13:32:22 +0000

States have been individually regulating gambling within their borders since they were English colonies. No one interpreted it as interstate commerce until PASPA in 1992, which was gutted by Murphy.

New comment by AlotOfReading in "Compression is prediction"

AlotOfReading — Wed, 12 Aug 2026 01:50:32 +0000

I think it's better to think of the hutter prize as a challenge to see how close people can get to efficiently approximating AIXI without the exponential cost of AIXItl. The fact that winners don't generalize well is just that they're not great approximations, because the behavior is different in the limit.

New comment by AlotOfReading in "Compression is prediction"

AlotOfReading — Tue, 11 Aug 2026 21:54:18 +0000

It might not be optimal, but it's not wrong to call it the best available guess. That's basically assuming Occam's razor / Solomonoff induction. Hutter published a bunch of work about what it means to have an "optimal" compressor and famously spent the past couple decades running a compression contest on the idea that it'd lead to insights in AI.

New comment by AlotOfReading in "Woman Pulled over at Gunpoint Twice After Flock Camera Glitch"

AlotOfReading — Tue, 11 Aug 2026 18:22:14 +0000

It's a self-fulfilling prophecy. If police treat every situation as a potentially dangerous engagement, they're actually actually increasing the likelihood that dangerous engagements occur.

New comment by AlotOfReading in "Why Can't You Pack a Bag? (2024)"

AlotOfReading — Mon, 10 Aug 2026 23:52:47 +0000

Most of that volume is air, and I use vacuum bags for storage/laundry organization. My jackets only take up the volume of a few t-shirts en route. Sweaters are more difficult, because I don't want to put handknit fabric into a vacuum bag, so the times I've needed to travel with those I wear them onto the plane as normal clothing, or slung over an arm.

New comment by AlotOfReading in "Why Can't You Pack a Bag? (2024)"

AlotOfReading — Mon, 10 Aug 2026 21:09:51 +0000

The description is a bit exaggerated, but I regularly see families with a large overhead suitcase + personal bag + secondary bag per person waiting at the carousel. I don't think many of them are diving in the places I go to, but who knows.

New comment by AlotOfReading in "Why Can't You Pack a Bag? (2024)"

AlotOfReading — Mon, 10 Aug 2026 21:02:07 +0000

I'm not sure what you're considering "heavier" clothes, but my layers work just fine to about -20C. It was a bit chilly the times it was <-40C, but I don't think that's what you meant?

The comment covered special gear, so not really sure what you want me to add there. I use a slightly larger bag that fits in overhead.

New comment by AlotOfReading in "Why Can't You Pack a Bag? (2024)"

AlotOfReading — Mon, 10 Aug 2026 20:31:22 +0000

I really don't understand what people are putting in the 2-3 large suitcases I see them struggling to shove in overhead. For one, rolling luggage is usually a mistake for anyone who's not flight crew.

I bring a week's worth of thin clothes that layer. If I need more, I'm either washing by hand or using a service. Basic toiletries, an e-reader, phone, keys, charger bricks, a notebook/pens, daypack. It fits into an underseat backpack with room to spare.

This has scaled fine all the way up to multi-month scientific expeditions in remote locations. Sometimes I need to accommodate specialized equipment like formal clothes/shoes, camera bodies/lenses, excavation equipment, tent, water purification, sleeping pad/bag, etc, but that's solved through the magic of bringing a slightly larger bag.