glangdale

9 ms·

1.
by glangdale 1y ago
I'm not sure what you mean here. A single cache line is 64B, and this table would thus occupy 4 cache lines, but typical x86 cache sizes are 32K or for more recent cores 48K. Whether consuming 1/512th or 1/768th of your lev
2.
by glangdale 1y ago
Yes, that's it. Vectorized SIMD annihilates this problem, a space I've been working in since 2006 and it wasn't all that new even then. A close second would be a heavily optimized (pipelined and less branchy) table or bitvect
3.
by glangdale 1y ago
To paraphrase Arthur Dent, "this must be a strange new usage of the word 'fastest' with which I am not previously familiar". The fastest way to detect a vowel in a string on any reasonable architecture (Intel or AMD equi
4.
by glangdale 2y ago
Yes, we have similar metrics in NSW (Australia). Agreed on the dynamics. There are also a lot if fairly feral edutech entrepreneurs playing special interest capture here - they obviously care more about selling their dubious education novel
5.
by glangdale 2y ago
100% this. Our kids were required to bring laptops to school for no particularly good reason, then allowed to zombie out on them in the library during lunch and free periods. Infuriating.
6.
by glangdale 2y ago
I'm sure you are a great person and all that, but in my experience, this particular recipe has produced absolute legions of smug, arrogant people who are nowhere near as smart as they think they are. Many of these people were dangerous
7.
by glangdale 2y ago
It's magnificently Paul Graham that he wrote some incredibly long essay called "The Origins Of Wokeness" without ever discussing, the origins of wokeness. Whatever you think about the current situation of "wokeness"
8.
by glangdale 2y ago
Not OP, but we use these tables all the time in Hyperscan (for string and character class matching) and it's a long-standing technique to use it for things like SIMD population count (obsoleted now if you have the right AVX-512 ISA, of
9.
by glangdale 2y ago
8 instructions seems very solid - guessing AND/PSHUFB for low nibble, SHIFT/AND/PSHUFB for high nibble, OR to combine plus load/store? If you have AVX-512, GFNI is faster for this task, but obviously many situations wher
10.
by glangdale 2y ago
This would be, speaking as someone who has dealt with his share of state machines, quite confusing. The uncomfortable thing about regular expression implementation as automata is either (a) non-determinism (i.e. "being in many states a
11.
by glangdale 4y ago
I always thought it was an odd turn of phrase; at most, you might have your speed detected by aircraft. "Enforced" always conjured up a picture of speed demons being strafed from above until they slowed down; maybe it's just
12.
by glangdale 5y ago
I started to build "simdcsv" - based on similar principles to "simdjson", but succumbed to lassitude. There's still a fork kicking around. Doing the CSV version of the quote convention is actually wildly easier than
13.
by glangdale 5y ago
To be clear, I don't approve of these "cancellations". Public universities are not well-protected in the United States from conservatives seeking to defund programs with which they disagree. One might be well-protected agains
14.
by glangdale 5y ago
I'm not going to get into a debate about whether Cotton is an idiot with a completely ahistorical view of slavery, but I think it's intriguing that he was pushing for a federal ban on a particular bit of educational content. I got
15.
by glangdale 5y ago
"Blog posts". Your mind is going to get blown when you find out there exist whole departments at universities that aren't sciences, and that there's kinda of a tradition of academic scholarship that goes back centuries
16.
by glangdale 5y ago
Deplatforming is not the only form of external pressure applied in the academic world. Getting entire university departments closed, for example, is considered a bit more final and effective. Also, it's interesting that even the very i
17.
by glangdale 5y ago
It's not inconsistent to want to 'badly want to help' groups that aren't on your political side. I may be a left-liberal, but working class conservatives arguing for lower taxes are in fact arguing for an arrangement tha
18.
by glangdale 5y ago
Some more examples: https://www.salon.com/2021/05/01/conservatives-claim-to-hate... A right-wing think tank with strong influence on Idaho legislators produces this gem of a report: 'The report doesn&#x2
19.
by glangdale 5y ago
Another good example (from a Nation article): "Arkansas Senator Tom Cotton, in a tizzy over the discontinuation by the estate of Dr. Seuss of six lesser-known books with racist content, had the audacity to gripe via social media that “
20.
by glangdale 5y ago
Followup: I can't Google up the studies I read on this, as all the terms I can think of are either overloaded or heavily partisan ("cancel culture"), etc. But I have a strong recollection of seeing quantitative data on number
21.
by glangdale 5y ago
> Schools are being pressured to remove books and cancel professors for spreading the “wrong” ideas. These sentiments are all too familiar to me, and to anyone who has survived life in a dictatorship. The only answer is more freedom, mor
22.
by glangdale 5y ago
You have a strange notion of what 'research' might be, which doesn't really map to either a academic notion of research ("write papers that might appeal to an {OS,PL,NS}DI committee") or a practical notion of resear
23.
by glangdale 5y ago
You mistake my reasons. Popularity is not an end in itself. Popularity, in this case, is a requirement to capture meaningful workloads to test what is purportedly a research operating system. The reason that Plan 9 failed as a platform for
24.
by glangdale 5y ago
If P9 had been able to run a reasonable number of computer programs not written by people at the Labs, it might have survived or at least been more influential beyond "UTF-8, some odd remnant uses of 9P, and /dev/proc".
25.
by glangdale 5y ago
It's not just a guide on how to do things with an operating system; it frequently veers off into the usual bizarre stuff about how no-one really needs proper office suites, databases, browsers, etc. In that, it's an encapsulation
26.
by glangdale 5y ago
Starting with a stripped-out Linux kernel and a standard toolchain (whether gcc or clang) would start you light-years ahead of Plan 9 and still permit you to do the kind of research a lot of us (including former 9fans) would love to see. Th
27.
by glangdale 5y ago
My criticism of Plan 9 as dead is realism, not intellectual incuriosity. Speaking of intellectual incuriosity, I find it astonishing that people are still poking the corpse in an effort to turn it into a daily driver, rather than discussing
28.
by glangdale 5y ago
There's a huge distinction between reviving the spirit of Plan 9 and reviving the ideas. Trying to retroactively revive the direction of an experimental early-90s OS to intercept 2020-era hardware is goofy. Computers are very different
29.
by glangdale 5y ago
This is worse than retrocomputing; it's necrocomputing, a pathetic attempt to mate with the corpse of a dead concept operating system. Instead of drawing any interesting lessons from Plan 9 for OS and distributed system design, it&#x27
30.
by glangdale 5y ago
p.s. Extraordinarily gifted and organized students at CMU were referred to be "on the 4 year plan". Interestingly, some of the most speedy completers of their PhD work were among the least well prepared for the MSc coursework - th

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