I built a GPU back end for Emacs • Hacker News Board

Re: I built a GPU back end for Emacs

#21

Post by andros » Thu, Jun 25, 2026, 6:37 PM UTC

reinitctxoffset wrote: post #19

This is outstanding, if I have time I'll be switching over today. This is the kind of thing that could drive a truly free fork of emacs forward, it's enough better on realistic desktop displays to rally around and as the parent discovered "Free Software" at this point has very little to do with the freedom to do what I want on my computer in a low friction way: an ideological position on "GPUs" as a category is bizar…

Thank you! A small correction on framing though: the goal is not a fork but a patch upstream. The backend is structured precisely to minimize the diff against Emacs mainline. The "nvim moment" comparison is flattering but I would rather this be the patch that makes the FSF argument easier to win than the one that splits the community. That said, your list of modernization items is a fair read of the backlog.

Re: I built a GPU back end for Emacs

#22

Post by andros » Thu, Jun 25, 2026, 6:38 PM UTC

bjourne wrote: post #18

Cool! Regardless of whether your code gets merged, it shows that xdisp.c can be tamed. Like Roger Bannister who ran the miracle mile, you showed that it can be done. Hopefully more will chip in and slay the Emacs redisplay code beast.

Thank you, this means a lot!

Re: I built a GPU back end for Emacs

#23

Post by reinitctxoffset » Thu, Jun 25, 2026, 6:38 PM UTC

andros wrote: post #5

skydhash wrote: post #4

This was almost a good read (a very good goal and a sensible approach), But the pacing of the article smells of LLM. I would suggest to do another pass at editing it out as it diminishes the story.

If you've reached that conclusion, I'm truly proud of my writing technique. I'm sorry to say, though, that your instincts are failing you this time. I write my articles by hand over several days, although it's true that I do consult AI to improve my style, expressions, find synonyms, create tables, and correct spelling mistakes. Thank you for your comment!

FWIW no one can tell anymore. Claude stopped doing all the LLM ticks like 6 months ago. There's a whole industry of people trying to detect LLM writing and they're getting stomped, this can be and is extremely well studied in the literature.

The criticism is that you did something wildly ambitious and pulled it off. The blog is just well written.

Re: I built a GPU back end for Emacs

#24

Post by arikrahman » Thu, Jun 25, 2026, 6:41 PM UTC

sph wrote: post #8

https://github.com/tanrax/emacs-gpu/blob/main/.github/assets... This massive speed-up on 4K screens makes me want to try it. The wayland pgtk version has such terrible latency I have to use the X11 build to avoid gnashing teeth during my working hours. And I think it's the X11 version that uses cairo, so the actual speedup in my case might be even larger. I reported the issue years ago, the pgtk maintainer confirmed,…

I didn't notice to much performance issue switching to PGTK on an ultrawide on Niri. Are you using the daemon to render Emacs as a client?

Re: I built a GPU back end for Emacs

#25

Post by abstractbg » Thu, Jun 25, 2026, 6:43 PM UTC

Interesting improvement. My biggest issue with Emacs and the reason that I left it was because it was not multi-threaded. I wonder if is/can be multi-threaded now.

Re: I built a GPU back end for Emacs

#26

Post by skydhash » Thu, Jun 25, 2026, 6:45 PM UTC

andros wrote: post #5

skydhash wrote: post #4

This was almost a good read (a very good goal and a sensible approach), But the pacing of the article smells of LLM. I would suggest to do another pass at editing it out as it diminishes the story.

If you've reached that conclusion, I'm truly proud of my writing technique. I'm sorry to say, though, that your instincts are failing you this time. I write my articles by hand over several days, although it's true that I do consult AI to improve my style, expressions, find synonyms, create tables, and correct spelling mistakes. Thank you for your comment!

I don’t think it failed. I was reading it and it did not seem written by a LLM (which I was happy for). But a few sentences did have LLM style and they disrupted my reading flow.

This is my heuristics: Usually when writing a story, authors adopt a fluid flow as they know they have your attention. Same as when telling a story. But LLM tooling usually adopt a highly emphatic tone similar to speeches: Short propositions, emotional crescendo, lots of contrast.

The difference in style is like abruptly going from a conversation to having your interlocutors doing a marketing speech in front of a crowd of one. It’s really jarring.

It’s not the whole piece. Just a few places here and there. If you’ve adjusted a few sentences, maybe try leaving them as is after fixing spelling mistakes.

Re: I built a GPU back end for Emacs

#27

Post by arikrahman » Thu, Jun 25, 2026, 6:49 PM UTC

Aside from the wonderful contribution to Emacs, I have the utmost respect for how straight-forward you were with the 100% LLM generated code. The enlightening conversation on GPU freedom that ensued was also informative.

Re: I built a GPU back end for Emacs

#28

Post by andros » Thu, Jun 25, 2026, 6:50 PM UTC

arikrahman wrote: post #27

Aside from the wonderful contribution to Emacs, I have the utmost respect for how straight-forward you were with the 100% LLM generated code. The enlightening conversation on GPU freedom that ensued was also informative.

I completely agree with you. For me, it was the best reward.

Re: I built a GPU back end for Emacs

#29

Post by internet_points » Thu, Jun 25, 2026, 6:51 PM UTC

could've guessed staying away from xdisp.c was a good idea, cf. the "Buttery Smooth Emacs"[0] post:

> Keep in mind that Emacs xdisp.c tries to support five different toolkits (including two different major versions of GTK) with #ifdefs. There is no runtime abstraction. We define three or four different versions of each damn function. It’s a nightmare.

[0] https://gist.github.com/ghosty141/c93f21d6cd476417d4a9814eb7...

Re: I built a GPU back end for Emacs

#30

Post by arikrahman » Thu, Jun 25, 2026, 6:52 PM UTC

reinitctxoffset wrote: post #19

This is outstanding, if I have time I'll be switching over today. This is the kind of thing that could drive a truly free fork of emacs forward, it's enough better on realistic desktop displays to rally around and as the parent discovered "Free Software" at this point has very little to do with the freedom to do what I want on my computer in a low friction way: an ideological position on "GPUs" as a category is bizar…

I agree. Nvim already takes notes out of emacs with major contributors using Funnel to use Lisp as a workaround for working with Lua. This would be a step in the right direction for the continued pioneer emacs proves to be.