sereja

8 ms·

31.
Battle of Karánsebes(en.wikipedia.org)
3 points by sereja 4y ago|0 comments
32.
by sereja 4y ago
There is "Programmers village" ("Поселок программистов") in Kirov Oblast in deep Russia. It is not exactly a rural community: it's just 20 or so families of remote tech workers (mostly freelancers) living a few kilo
33.
BLAS-level matrix multiplication in under 40 lines of C(en.algorithmica.org)
3 points by sereja 5y ago|0 comments
34.
B− tree: 15x faster than std::set(en.algorithmica.org)
2 points by sereja 5y ago|1 comments
35.
by sereja 5y ago
Flushing the cache is easy: just read 4MB (or whatever your L3 cache size is) of some dummy data and pretty much everything you had cached before would be kicked out. At the same time, resetting the branch predictor AFAIK can only be done b
36.
China-Russia trade has surged as countries grow closer(reuters.com)
99 points by sereja 5y ago|106 comments
37.
by sereja 5y ago
I briefly talk about noise reduction in the "Getting Accurate Results" section: https://en.algorithmica.org/hpc/profiling/noise/ I don't follow my own advice in much of the rest of the book, th
38.
by sereja 5y ago
> The e-book/printed editions will most likely be sold on a “pay what you want” basis, and in either case, the web version will always be available online in full. I will get out of Russia in a few months and then figure out the bes
39.
Ask HN: Which companies are hiring developers fleeing from Ukraine and Russia?
8 points by sereja 5y ago|2 comments
40.
by sereja 5y ago
I've already implemented a 32-byte version. But, as mentioned in the article, it's not faster (in terms of throughput) because it needs to fetch two cache lines.
41.
by sereja 5y ago
That's because it is in bytes, representing cache sizes. But I agree, a clarification is needed
42.
by sereja 5y ago
Probably not a lot, but the idea of using 2k and 2k + 1 as indices for children is used in a lot of basic data structures taught in CS courses, e. g. for binary heaps.
43.
by sereja 5y ago
Hmm... using blend is actually a good suggestion. You can pre-shuffle elements [1 3 5 7] [2 4 6 8], do a comparison against the search key, and then blend the low 16 bits of the first register with the high 16 bits of the second. Will add t
44.
by sereja 5y ago
By the time I realized it needs correcting, I was already like 15 graphs in and really didn't want to remake them.
45.
Static B-Trees: A data structure for faster binary search(en.algorithmica.org)
306 points by sereja 5y ago|49 comments
46.
by sereja 5y ago
It's called superscalar processing. CPUs can execute more than one instruction concurrently on each pipeline stage if there is no dependency between them. In the prefix sum, we can fetch and add the next element simultaneously with the
47.
by sereja 5y ago
A single CPU core usually can't saturate the memory bandwidth (because it would require more pending memory operations than the scheduler can handle). If you use all cores, it will approach the theoretical limit. https://en.
48.
by sereja 5y ago
It is not technically legal to use SIMD on most floating-point loops, including the inner product in matrix multiplication, because rounding errors are not commutative. C compilers don't vectorize such loops either unless you pass the
49.
by sereja 5y ago
Author here. I wrote a separate section trying to answer this question: https://en.algorithmica.org/hpc/complexity/languages/ tl;dr: to some extent, but mostly no
50.
Machine Code Layout Optimization(en.algorithmica.org)
4 points by sereja 5y ago|0 comments
51.
Argmin with SIMD(en.algorithmica.org)
3 points by sereja 5y ago|0 comments
52.
by sereja 5y ago
Leonid Volkov, a Russian oppositionist and the chief of staff of Alexei Navalny's 2018 campaign. The Russian government wants to arrest him for being a key member of the Anti-Corruption Foundation, which it brands as "extremist&qu
53.
Negotiating with Compilers(en.algorithmica.org)
10 points by sereja 5y ago|1 comments
54.
Binary GCD(en.algorithmica.org)
17 points by sereja 5y ago|2 comments