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jjmarr

4,411 karmajoined 2 tahun yang lalu
All views are my own. Software Engineer II @ AMD

jjmarr.com

Submissions

Floating Armoury

en.wikipedia.org
1 points·by jjmarr·2 bulan yang lalu·0 comments

I tricked 3M people into believing in an evil fake polycule

rawandferal.substack.com
25 points·by jjmarr·2 bulan yang lalu·1 comments

Cppreference.com has completed their migration and is no longer read-only

isocpp.org
4 points·by jjmarr·3 bulan yang lalu·0 comments

The American consumer market is larger than the EU and China's combined

en.wikipedia.org
5 points·by jjmarr·3 bulan yang lalu·5 comments

Façade (2005 Video Game)

en.wikipedia.org
5 points·by jjmarr·3 bulan yang lalu·0 comments

A Proposed Improvement to the Diet Coke and Mentos Experiment (2016)

physics.stackexchange.com
3 points·by jjmarr·3 bulan yang lalu·0 comments

Shrimp fishing on horse back in Oostduinkerke

en.wikipedia.org
3 points·by jjmarr·4 bulan yang lalu·0 comments

Radical Forces in Germany (1931)

foreignaffairs.com
2 points·by jjmarr·5 bulan yang lalu·1 comments

Sl − display animations to correct users who accidentally enter sl instead of ls

man.cx
2 points·by jjmarr·5 bulan yang lalu·0 comments

Ask HN: Why do most AI assistants start with the letter C?

3 points·by jjmarr·6 bulan yang lalu·2 comments

Wait, You Can Unpack That with Structured Bindings?

jjmarr.com
1 points·by jjmarr·6 bulan yang lalu·2 comments

comments

jjmarr
·3 hari yang lalu·discuss
Alan Greenspan (fed chair from 1987-2006) was famous for deliberately confusing forward guidance. Ben Bernanke and Janet Yellen are the historical anomalies for clearly communicating their intent.

https://en.wikipedia.org/wiki/Fedspeak

Quote from Greenspan himself:

> As Fed chairman, every time I expressed a view, I added or subtracted 10 basis points from the credit market. That was not helpful. But I nonetheless had to testify before Congress. On questions that were too market-sensitive to answer, 'no comment' was indeed an answer. And so you construct what we used to call Fed-speak. I would hypothetically think of a little plate in front of my eyes, which was the Washington Post, the following morning's headline, and I would catch myself in the middle of a sentence. Then, instead of just stopping, I would continue on resolving the sentence in some obscure way which made it incomprehensible. But nobody was quite sure I wasn't saying something profound when I wasn't. And that became the so-called Fed-speak which I became an expert on over the years. It's a self-protection mechanism ... when you're in an environment where people are shooting questions at you, and you've got to be very careful about the nuances of what you're going to say and what you don't say.
jjmarr
·4 hari yang lalu·discuss
> An arms race is the inevitable outcome. It's either that or competitive gaming is not viable.

I'd rather just give my passport and do one of those face turning challenges to play competitive video games. Then if I get caught cheating, my real life identity can't play anymore, rather than make a new account and "get better at cheating".

If I am a habitual cheater in literally any other sport on Earth, governing body figures that out and issues me a lifetime ban. At that point, I'm blacklisted. Even my Tuesday night dodgeball league can issue bans that actually stick because they know my real identity.
jjmarr
·4 hari yang lalu·discuss
You can buy an autoclicking device or software that recognizes screen pixels of enemy avatars and instantly clicks to kill them. This works in "remote streaming" situations and is ~30% of the cheating dataset detected by Riot's kernel level anticheat:

https://www.riotgames.com/en/news/vanguard-on-demand

> A “pixelbot” is a computer vision cheat that injects player input for the purposes of aiming at heads or casting spells with perfect timing. Coming in “external” (hardware microcontroller) and “internal” (python script) varieties, pixelbots can be extremely impactful in VALORANT due to the low time-to-kill, sometimes just simply pulling the trigger for the cheater when an enemy enters their reticle (also known as a “triggerbot”).
jjmarr
·4 hari yang lalu·discuss
It was very fun. Brick Battle, Galleons, the game with many towers. The explodey terrain put Roblox on the map initially.

The problem is the opportunity cost of destructible terrain was too high. Developers could get fun for lower effort by creating linear levels with better design/graphics/etc as destructible terrain makes everything "blocky" without significant developer work.
jjmarr
·4 hari yang lalu·discuss
Counterpoint is Roblox, which had one of the most innovative game engines ever. It could multiplayer simulate thousands of blocks of destructible terrain in 2006.

This feature was mostly ignored by the playerbase because developers found it easier to create static setups and focus on iterating on other parts of their gameplay.
jjmarr
·8 hari yang lalu·discuss
Because the TPM effectively rate limits brute forcing of the key.

https://learn.microsoft.com/en-us/windows/security/hardware-...

> For example, when BitLocker is used with a TPM + PIN configuration, the number of PIN guesses is limited over time. A TPM 2.0 in this example could be configured to allow only 32 PIN guesses immediately, and then only one more guess every two hours. This totals a maximum of about 4,415 guesses per year. If the PIN is four digits, all 9999 possible PIN combinations could be attempted in a little over two years.
jjmarr
·9 hari yang lalu·discuss
Japan has stigma towards used houses.
jjmarr
·9 hari yang lalu·discuss
Airports are such a place. That is why they have duty-free stores that are exempt from taxes so long as you take the goods out of the country. The onus is on the consumer to pay taxes at their destination.

Most countries then have a "personal exemption", where consumers are exempt from paying taxes on a certain value of goods.
jjmarr
·12 hari yang lalu·discuss
Building a "Canadian equivalent" of something else is a great way to get money from the Canadian government right now.

In addition to direct subsidies/grants, the government has a buy Canadian mandate.
jjmarr
·13 hari yang lalu·discuss
Technoethical sells a refurbished T400 with GNU Boot.

https://tehnoetic.com/laptops/tet-t400s

Libreboot actually isn't free anymore by FSF standards because it has binary blobs for the Intel Management Engine. Neither is Coreboot which has blobs for many other things. Most modern computers cannot boot without binary blobs for ME, which is why GNU Boot was created.

If you want a modern/new computer, Purism sells them with the management engine "neutralized" but it's still not free by FSF standards because they haven't bypassed it entirely.

https://puri.sm/learn/intel-me/
jjmarr
·13 hari yang lalu·discuss
No, because you're doing decimal floating point, which eliminates the rounding errors of binary floating point.
jjmarr
·14 hari yang lalu·discuss
I've never understood this argument. I regularly run insmod and/or modprobe to load kernel modules.

I'm guessing it's because Linux constantly breaks ABI for out-of-tree kernel modules. And because every version of a distro can have a different kernel it's a nightmare of a support matrix.

That and Secure Boot establishing a chain of trust. Valorant requires Secure Boot and TPM 2.0 which means users can't modify the kernel driver. I'm not sure if Valorant wants to distribute their own Secure Boot keys and sign all the distro kernels + their module.
jjmarr
·14 hari yang lalu·discuss
That's literally the official FSF position.

https://www.fsf.org/resources/hw

> For example: the Free Software Foundation only purchases desktop machines which support Libreboot, and Thinkpad X200 and X60 laptops with Libreboot. All desktops and servers we buy are KGPE-D16 motherboards, which are supported by Libreboot. As a result, all of the workstations used by the FSF staff have a free BIOS.

https://www.gnu.org/distros/common-distros.html

> Except where noted, all of the distributions listed on this page fail to follow the guidelines in at least two important ways:

> ...The kernel that they distribute (in most cases, Linux) includes “blobs”: pieces of object code distributed without source, usually firmware to run some device.

They are extreme, uncompromising, and live by their principles.

They are also the reason you can buy a computer meeting those requirements instead of being a pipe dream.
jjmarr
·14 hari yang lalu·discuss
"Chess-related roguelike" is a an very crowded genre for unclear reasons and it's difficult to stick out.

So far I've played Shotgun Queen and Pawnbarian. There's also Ouroboros King, Demoncrawl, The Rookery, Passant, Chess Survivors, Gambonanza, Mind over Monarchy, and many more.

There was even a Humble Bundle for mostly Chess-inspired indie roguelikes.

https://www.humblebundle.com/games/checkmate-chess-games-col...
jjmarr
·14 hari yang lalu·discuss
"Chess-related roguelike" is a an very crowded genre for unclear reasons and it's difficult to stick out.

So far I've played Shotgun Queen and Pawnbarian. There's also Ouroboros King, Demoncrawl, The Rookery, Passant, Chess Survivors, Gambonanza, Mind over Monarchy, and many more.
jjmarr
·15 hari yang lalu·discuss
This is brilliant, except for the "alignment won't stop this part".

> Now, some people believe these machines can be made to serve humanity. Does it sound reasonable to imagine a superhumanly intelligent being that is happy to work as a butler to talking primates, forever?

The whole crux of the piece to me is that the AI can be 100% aligned to follow human instructions, and we'd still end up unable to control the AI because every human who can has an incentive not to, while also having an incentive to prevent anyone else from controlling the AI.

An LLM will never try to overthrow me because I will overthrow myself.
jjmarr
·15 hari yang lalu·discuss
From page 175 of the AMD CDNA4 ISA:

https://www.amd.com/content/dam/amd/en/documents/instinct-te...

> V_MUL_U32_U24

>,Multiply two unsigned 24-bit integer inputs and store the result as an unsigned 32-bit integer into a vector register. D0.u32 = 32'U(S0.u24) * 32'U(S1.u24)

> Notes

> This opcode is expected to be as efficient as basic single-precision opcodes since it utilizes the single-precision floating point multiplier. See also V_MUL_HI_U32_U24.

Nvidia GPUs used to do the same thing and theres a umul24 intrinsic if you care to use it.

https://stackoverflow.com/questions/5544355/cuda-umul24-func...

This is super-super-niche since it basically only applies to 32-bit integer multiplication.

You likely won't run into it unless you're doing high performance embedded systems or GPU programming on non-NVDIA cards, and for some unknowable reason, your workload does a 32-bit integer multiplication in the hot path.
jjmarr
·15 hari yang lalu·discuss
> Just don't allow casting to u24, as it makes no sense unless you define u24 to be u32 sized as I think c standard does.

The reason u32->u24 casting must be well defined is because some hardware (e.g. many GPUs, microcontrollers) only have floating point multipliers. A 24 bit unsigned integer (stored in a 32 bit register) can be losslessly converted to a 32 bit float by the hardware, multiplied, then converted back.

This is much faster than doing 32 bit multiplication in software, however, you still need to tell the compiler about this constraint.
jjmarr
·16 hari yang lalu·discuss
From playing Stellaris, it was all bottlenecked on a single threaded pop simulation which is why it got so laggy in the endgame.

Most "CPU intensive" games I've noticed are like that.
jjmarr
·17 hari yang lalu·discuss
It has gotten worse. Shadow of the Erdtree requires you to kill a boss (Mohg) hidden within a SECRET AREA (Mohgwyn Palace) hidden within ANOTHER secret area (Consecrated Snowfield).

And the Consecrated Snowfield is only accessible if you find two parts of a hidden medallion, the first in a castle later in the game than the lift it operates. The second is hidden in a jar underneath a mountain. But you can't just smash the jar, you have to talk to the NPC inside the jar twice before you'll get the medallion.

The market rewards abstruse design.