bertr4nd

12 ms·

61.
by bertr4nd 6y ago
What is method scoring? I’ve never heard that term in VM/compilers and my Google-fu is failing me.
62.
by bertr4nd 6y ago
I’m not sure if the feature was added after you started building Please but Buck does support multiple outputs from a genrule now. It’s kind of hacky though; you write a genrule that produces a directory containing said multiple outputs, a
63.
by bertr4nd 6y ago
My reading of section 8.2.1 suggests that it is not UB to copy bytes from an object of one type to an object of another type, and then to read the value of the second object, since it is explicitly allowed to access each object as bytes.
64.
by bertr4nd 6y ago
Zero-length arrays, used to implement a variable-sized structure with header: https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html . Although apparently it’s a GCC extension, which I didn’t realize until now.
65.
by bertr4nd 6y ago
How many people make it to that $2-20MM partner bracket in consulting? That’s VP range at FAANG and while there are only so many VPs they certainly exist.
66.
by bertr4nd 6y ago
Autotools vs cmake is just no contest from a developer’s perspective. I set up one project with autotools a few years back and the experience was horrible: lots of weird incantations, obfuscated syntax, piles of m4 macros to do what feel l
67.
by bertr4nd 6y ago
I was being glib in the description but it’s not like PageRank is a crazy idea either, is it? The reason I’m prodding at this is because there are different ways in which someone can fail to understand the value of an idea. The value propo
68.
by bertr4nd 6y ago
I’ve only once worked under a manager who also coded, and I had extremely mixed feelings. On the one hand, he was a brilliant engineer who I learned a ton from, and who set a really solid technical direction for the team. On the other hand
69.
by bertr4nd 6y ago
Something I don’t understand in this article is the “People won’t understand your ideas if they’re any good.” Like, the idea behind Google is, “Let’s make another search engine, but make it really good.” That’s not a crazy idea, is it? W
70.
by bertr4nd 6y ago
I’d be curious to see the instruction sequences for handling overflow without condition codes. I’m not even sure I see how to do it as efficiently as 3 or 5 instructions :-/
71.
by bertr4nd 6y ago
It’s not just the I$ though, it’s the MLC, LLC, and I-TLB. And instruction density at those levels actually matters quite a lot for big binaries (my experience in this regard is with HHVM at FB, but it’s certainly not unique).
72.
by bertr4nd 6y ago
By “mirroring the includes” do you just mean listing the .h files in the build files? Don’t most build systems already have that problem for cpp files? Tbh I prefer also being explicit about the headers packaged in a library as well as th
73.
by bertr4nd 6y ago
Right - I mean, I’m not confused about what’s going on, now that I’ve seen the result. But I do think it is surprising that `unsigned int` and `unsigned short` behave differently in this expression, even if I basically see the logic in the
74.
by bertr4nd 6y ago
Woah, there's even a scary gotcha for types that aren't unsigned. E.g., check out what happens with "unsigned short": https://gcc.godbolt.org/z/4xWo1G . It looks like -n is implicitly converted (to
75.
by bertr4nd 6y ago
First it's important to note that `n` is unsigned; if it's signed the value of `-n % n` is 0, intuitively. For unsigned n, the value is: MAX - n + 1 (where max is the maximum representable value in the type of n, e.g., UINT_MAX).
76.
by bertr4nd 6y ago
One of the reasons it’s hard to talk about clean C++ codebases is that there’s a huge range of possible complexity. The gap between “Solve a particular problem” and “provide a generic library” is very big. Template metaprogramming deserve
77.
by bertr4nd 6y ago
> Contributors want to do their work, not investigate "what does a git clone really do". Exactly this. Especially if the repo and CI pipeline are complicated, it is incredibly easy to just assume “it’s slow” is a fact of life.
78.
by bertr4nd 6y ago
And the same person can be unhappy for different reasons no matter what choices they make. After a few of those, one starts to distrust almost any decision-making framework :) If it helps (and it probably doesn’t, much) try not to beat your
79.
by bertr4nd 6y ago
We’re so far off topic, but I agree with you SO much. <chrono> completely resists my attempts to remember how to do anything with it, no matter how many times I have needed to do something trivial like “time this region of code.”
80.
by bertr4nd 6y ago
I wonder if the search for an alternative to the “hallway track” could actually be fruitful. Speaking for myself I never benefited much from the hallway track, because it relies on the type of in-person socializing skills that I’ve always s
81.
by bertr4nd 6y ago
Right, so I think the suggestion of brainfuck illustrates the difficulty I’m having articulating what I want, because while it’s TC and trivial to implement, it is basically impossible to use as a language. I think I’m going for simultaneo
82.
by bertr4nd 6y ago
A related idea that I’m interested in but find a bit hard to articulate is to describe “simple” Turing complete languages, where simplicity is defined more by ease of reasoning for a human than by any objective metric. Basically, if I wante
83.
by bertr4nd 7y ago
I would guess that the difficulty of preventing cheating in an online setting discourages institutions from going fully online. For masters work and above I suspect this concern is less prominent because it’s likely to be a smaller student
84.
by bertr4nd 7y ago
In grad school some of my lab mates accidentally fork-bombed UT Austin’s entire CS department compute cluster. Someone had written this weird re-entrant shell script that would, depending on arguments, either submit a batch of jobs to the
85.
by bertr4nd 7y ago
I just read Bryan Ward-Perkins’s “The Fall of Rome” and it argues pretty persuasively that the era after the fall was materially worse off than during the Roman Empire. Specifically the quality and quantity of manufactured artifacts and dw
86.
by bertr4nd 7y ago
Something I like about This advice is that it puts the research idea at the center of the writing. Too often these sort of recommendations don’t seem to even acknowledge that “having a worthwhile idea” is important, and make it sound like
87.
by bertr4nd 7y ago
Yes! In fact that’s from the same team I was working on at the time (HHVM). My tool predated BOLT by a few years, I think. Obviously BOLT is way more sophisticated and does an even better job.
88.
by bertr4nd 7y ago
We wrote this paper about it for CGO: https://research.fb.com/publications/optimizing-function-pla... . But the paper actually describes a significantly more sophisticated heuristic. My initial implementation simply us
89.
by bertr4nd 7y ago
I wrote a little tool that used perf profiles from our production fleet to generate a custom linker script that reordered our main server program’s binary to be significantly more cache friendly. The heuristic I came up with for reordering
90.
by bertr4nd 7y ago
I notice this effect all the time when cooking, and the maddening part is how hard it can be to even figure out the right details. Like, the best sausages I ever cooked were at a barbecue in park, on a random public grill with no particular

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