853 karma · joined October 4, 2016
If I recall correctly, a recent post [1] has shown that Q2 quants (with like 2.6 bpw) of the same base Qwen model sit at the edge between "noticeably worse" and Q1's "useless". I took a quick glance at Bonsai's blog posts, and don't really see them comparing themselves to "typical" quants or explaining what's the special sauce that makes them better?
Fun fact, this _used_ to be the case - wasm32-unknown-unknown had extra non-mvp features added later, which in my eyes has been a breaking change on stable. You're not the first person to have been bitten by this, there's [1] and a similar story in Ruffle [2].
Weirdly, the response from the rustc side (IIRC we also talked with one of the devs of wasm component on discord a bit around 2024) has contained a lot of (paraphrasing) "in retrospect we think wasm32-unknown-unknown target was designed badly*, so we'd prefer if you either dealt with it or switched to another wasm target <with its different set of downsides> than us fixing it". (*I acknowledge that the way std was implemented on that target was unusual and "not clean", but it works _really well_ for a lot of people.)
> I looked into the process involved for rebuilding the standard library twice: once with only MVP wasm features enabled and once with an "all yes config" like usual. Based on some research I did this seemed like a massive pain.
That's what Ruffle does [3], it's a bit unfortunate but wouldn't call it a massive pain.
[1] https://internals.rust-lang.org/t/can-we-have-either-a-new-t...
[2] https://github.com/ruffle-rs/ruffle/pull/18397
[3] See lines 55 and 117-127 in https://github.com/ruffle-rs/ruffle/blob/6890c618daab3153343...
> art
Small pushback here: it (and bluesky too) is absolutely atrocious for art, at least as a consumer. Once in a while I stumble upon an artist who only posts their drawings on twitter/bsky, and it’s pretty much impossible to browse their historical works because the „media” tab is just an infinite scroll without any organization; and that’s assuming they don’t also post 10 photos of their cat or other life updates in between their art.
It’s obviously still popular for posting art for many other reasons (I just dislike putting „X”, „art” and „does well” in the same sentence). So IMO the replacements - and lots of these use cases already gave replacements! - struggle simply because of network effects, not their inherent quality.
Might be the first time I see someone complain about their website being protected from a scraper, instead of the other way around.
I saw some eve-specific logic in Destiny repo, like warp enter condition and warp velocity math, or entity visibility between grids.
(Also, it’s full of std::(unordered_)map/set. Surprised they didn’t try squeeze some more perf there.)
The extra diff files are only there because the quantization is not fully reproducible*, and author's 3-line llama.cpp fix PR** supposedly fixes this. With it fixed, then in my understanding the author's tool is literally just a wrapper around llama-quantize.
* I also wonder if this even matters for quant quality. In fact, isn't it possible for contracted FMAs to be more numerically accurate (even if less correct from IEEE pov) than non-contracted math?
** I'd give the PR like 50% chances of not surviving the day, since AFAIK on llama.cpp, vibed PR descriptions usually end up rejected as a rule. Maybe the diff being super trivial could save it from this fate, dunno.
The "dissertation" linked there (https://github.com/b7r6/cassandra-dissertation) is also incredibly interesting; looks like the HN user asked an LLM to prove/validate that they are "right" in their comments more often than not.
In general, these GH accounts and their repos/gists are kind of a rabbit hole.
I buy a VPS. I apt install nginx. Is it okay that by default, opening http://IP/index.html logs the IP address to /etc/log/nginx/access.log? Maybe yes, maybe no, maybe yes but I need a privacy policy (for an empty index.html). Maybe I need to ask a lawyer (who usually errs on side of caution) because people have been arguing about it for 10 years (and please don't answer here). And in the end, even if I didn't need to do anything, it sure is _some_ nonzero drain of my resources to have think about it at all (completely ignoring whether it's justified or not).
There's another issue that popped up on my quick naive profiling run: std::shared_ptr<Material> in the HitRecord/HittableLightSample is assigned/copied and destroyed a lot, and somehow these refcount operations show up as half of all samples on my profile (presumably because even if there's no hit and the pointer stays nullptr, the smart pointer still must check if there's anything to deallocate).
> If the resulting pointer is not correctly aligned for the pointed-to type, the behavior is undefined.
However, unless I’m missing something, producing such a pointer from an integer is apparently not insta-UB? 6.3.2.2.5:
> An integer may be converted to any pointer type. Except as previously specified, the result is implementation-defined, might not be correctly aligned, might not point to an entity of the referenced type, and might be a trap representation
And later on 6.5.3.2.4:
> If an invalid value has been assigned to the pointer, the behavior of the unary * operator is undefined.
Which implies that the invalid pointer must have been obtained without being already undefined, right?
> First off, templates are the opposite of opaque due to the fundamental requirement that the implementation be visible to every translation unit using a template.
That's not strictly true, you can have an implementation hidden in a separate TU, as long as that TU instantiates the template for all template arguments that the users are going to use.
(*hopefully I didn't misunderstand the situation)
At a glance, I see they do gather analytics about how much the app is used (model downloads, model invocations etc) without message content, pretty much just the model used.
- C library
- neovim plugin
- MCP server
But not a plain binary, which is the main way ripgrep is directly used (...at least by humans), and compared with.
Didn't Valve push Steam through HL2? It's a different kind of forcing of course, but still.
I also did some reading and experiments, so quickly talking about things I've found out re: refcount elimination:
Previously given an expression `c = a + b`, the compiler generated a sequence of two LOADs (that increment the inputs' refcounts), then BINARY_OP that adds the inputs and decrements the refcounts afterwards (possibly deallocating the inputs).
But if the optimizer can prove that the inputs definitely will have existing references after the addition finishes (like when `a` and `b` are local variables, or if they are immortals like `a+5`), then the entire incref/decref pair could be ignored. So in the new version, the DECREFs part of the BINARY_OP was split into separate uops, which are then possibly transformed into POP_TOP_NOP by the optimizer.
And I'm assuming that although normally splitting an op this much would usually cost some performance (as the compiler can't optimize them as well anymore), in this case it's usually worth it as the optimization almost always succeeds, and even if it doesn't, the uops are still generated in several variants for various TOS cache (which is basically registers) states so they still often codegen into just 1-2 opcodes on x86.
One thing I don't entirely understand, but that's super specific from my experiment, not sure if it's a bug or special case: I looked at tier2 traces for `for i in lst: (-i) + (-i)`, where `i` is an object of custom int-like class with overloaded methods (to control which optimizations happen). When its __neg__ returns a number, then I see a nice sequence of
_POP_TOP_INT_r32, _r21, _r10.
But when __neg__ returns a new instance of the int-like class, then it emits
_SPILL_OR_RELOAD_r31, _POP_TOP_r10, _SPILL_OR_RELOAD_r01, _POP_TOP_r10, etc.
Is there some specific reason why the "basic" pop is not specialized for TOS cache? Is it because it's the same opcode as in tier1, and it's just not worth it as it's optimized into specialized uops most of the time; or is it that it can't be optimized the same way because of the decref possibly calling user code?
struct S { const int x; int f() const; }; int S::f() const { int a = x; printf("hello\n"); int b = x; return a-b; }
The compiler can't reuse 'x' unless it's able to prove that it definitely couldn't have changed during the `printf()` call - and it's unable to prove it. The member is loaded twice. C++ compilers can usually only prove it for trivial code with completely inlined functions that doesn't mutate any external state, or mutates in a definitely-not-aliasing way (strict aliasing). (and the `const` don't do any difference here at all)
In Python the difference is that it can basically never prove it at all.
Similarly, I don't entirely understand refcount elimination; I've seen the codegen difference, but since the codegen happens at build time, does this mean each opcode is possibly split into two (or more?) stencils, with and without removed increfs/decrefs? With so many opcodes and their specialized variants, how many stencils are there now?
- the outputs, even if correctly deduced, are often incompatible: "utf-16be" turns into "utf-16-be", "UTF-16" turns into "utf-16-le" etc. FWIW, the old version appears to have been a bit of a mess (having had "UTF-16", "utf-16be" and "utf-16le" among its outputs) but I still wouldn't call the new version _compatible_,
- similarly, all `ascii` turn into `Windows-1252`
- sometimes it really does appear more accurate,
- but sometimes it appears to flip between wider families of closely related encodings, like one SHIFT_JIS test (confidence 0.99) turns into cp932 (confidence 0.34), or the whole family of tests that were determined as gb18030 (chinese) are now sometimes determined as gb2312 (the older subset of gb18030), and one even as cp1006, which AFAIK is just wrong.
As for performance claims, they appear not entirely false - analyzing all files took 20s, versus 150s with v6.0. However, looks like the library sometimes takes 2s to lazy initialize something, which means that if one uses `chardetect` CLI instead of Python API, you'll pay this cost each time and get several times slower instead.
Oh, and this "Negligible import memory (96 B)" is just silly and obviously wrong.