regehr

10 ms·

31.
by regehr 11y ago
Here's a different study with similar findings: http://www.econ.ucdavis.edu/faculty/scarrell/profqual2.pdf "... our results show that student evaluations reward professors who increase achievement in the
32.
by regehr 12y ago
Watching TV/movies is definitely something that we learn to do, though most of us learned so early that we no longer remember it. Source: anecdotal evidence from friends/relatives who observed childrens' reactions when first
33.
by regehr 12y ago
Often, the sound from the scene following the cut precedes the cut itself. There must be a name for this technique and a reason for it-- anyone know?
34.
by regehr 12y ago
Awesome books on this topic: http://www.amazon.com/Commissar-Vanishes-Falsification-Photo... http://www.amazon.com/Photo-Fakery-History-Deception-Manipul...
35.
by regehr 12y ago
512 kbps DSL -- just barely, frustratingly capable of watching Netflix at the worst quality level
36.
by regehr 12y ago
I bought a house about 1 mile from downtown Salt Lake City in 2008 and it took until last year to get a decent internet connection (from Comcast). First world problems!
37.
by regehr 12y ago
It's usually a combination of (1) being afraid of sounding unrigorous or unintelligent and (2) not knowing any better and having been trained on lots of bad examples This book is excellent: http://www.amazon.com/Stylish
38.
by regehr 12y ago
I routinely forego summer salary in order to make sure the students are fed. This works because I receive a perfectly adequate 9-month salary from the state (and also my household has two incomes).
39.
by regehr 12y ago
I'm the author of this piece. Everyone should go try out Alive instead of reading the blogpost: https://github.com/nunoplopes/alive Alive automates all of the stuff described in the post. Here's some info:
40.
by regehr 12y ago
Does this example help? http://markshroyer.com/2012/06/c-both-true-and-false/
41.
by regehr 12y ago
The linked articles by Chris Lattner explain why this is very difficult. http://blog.llvm.org/2011/05/what-every-c-programmer-should-...
42.
by regehr 12y ago
We found that UNSAFE/TRUSTED code wasn't needed very often. YMMV.
43.
by regehr 12y ago
Wrong, incorrect Deputy annotations (other than the UNSAFE annotation) cannot lead to memory safety violations. I edited to post a bit to make this more clear.
44.
by regehr 12y ago
It's not just the function that becomes undefined, it's the entire program. There's literally nothing that the compiler is supposed to do following undefined behavior.
45.
by regehr 12y ago
Absence of undefined behavior in the C implementation is of course one of the things covered by the seL4 proof.
46.
by regehr 12y ago
I never wrote up all the details (which seemed somewhat mundane, since the bugs were in unproved code) but see Section 3.1 here: http://www.cs.utah.edu/~regehr/papers/pldi11-preprint.pdf
47.
by regehr 12y ago
John Regehr (me) did in fact find something like 11 bugs in CompCert, most of which caused it to emit wrong code. But the bugs were not in the proved part.
48.
by regehr 12y ago
Metamorphic testing means taking an existing test case and mutating it into a new test case that produces the same answer (or at least an answer that can be easily predicted). Property-based testing is, as far as I can tell, a meaningless t
49.
by regehr 12y ago
4. PROFIT
50.
by regehr 12y ago
Please do, if it is not too much trouble.
51.
by regehr 12y ago
I'm still interested in somehow creating such a test suite, Pascal -- one that is designed to test corner cases in the standard rather than testing corner cases in the optimizer. It would somehow be derived from various formalizations
52.
by regehr 12y ago
Pascal, have you reported the bug? Xuejun is doing some Csmith work right now and we can probably get him to fix it.
53.
by regehr 12y ago
Sorry if I was unclear. The missing folds are at the C level. At the LLVM level we definitely run InstCombine before Souper (otherwise we would find lots of optimizations that are not actually missing).
54.
by regehr 12y ago
The immediate goal is simply to inspire LLVM hackers to improve the instruction combiner. But yes, these results can be made persistent and used directly to optimize code. We are working on it. Applying this tool to code emitted by GHC or r
55.
by regehr 13y ago
They're just following the financial jobs! I wasn't much of an outdoors person before moving to Utah and really, really like that stuff now too.
56.
by regehr 13y ago
A major natural disaster is a certainty in the SLC area: we're surrounded by active faults.
57.
by regehr 13y ago
I live in SLC and have met quite a few people over the last few years who lost jobs in the financial sector, usually in the NYC area, and subsequently moved to Utah.
58.
by regehr 13y ago
Fucking Dreamhost...
59.
by regehr 14y ago
I always find it depressing when I take a picture by moonlight and it ends up looking very much like a picture taken by sunlight, as opposed to looking like the scene looks to our eyes. Always have to keep in mind that a CCD != rods and co
60.
by regehr 14y ago
Same here. Perhaps it uses a direct drawing API.

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