danlark1

6 ms·

1.
by danlark1 2mo ago
Congrats, that's incredible news. Watched apavlo@'s lectures while studying in the university and finished my bachelor thesis implementing features and doing research at ClickHouse. Surprised to see these worlds being together now
2.
by danlark1 3mo ago
It's a somewhat known tradeoff, you can streamline and make the format friendlier to do memcpy which this library targets, the more memcpys you do, the faster it is overall to decode. On highly compressible data lz4, snappy become fast
3.
by danlark1 9mo ago
Surprisingly I didn't put 2023, it was merged with another submission possibly with the help of mods
4.
Performance Hints(abseil.io)
143 points by danlark1 9mo ago|43 comments
5.
by danlark1 11mo ago
Yes, sorry, it should be "disclosure"
6.
by danlark1 11mo ago
Disclaimer: the author of the comment is the founder and CTO of ClickHouse
7.
by danlark1 1y ago
Great work! Popular narrative that NEON does not have a move mask alternative. Some time ago I published an article to simulate popular bit packing use cases with NEON with 1-2 instructions. This does not include unpacking cases but can be
8.
by danlark1 1y ago
I am the author of the optimization of partial sorting and selection in Clickhouse. It uses Floyd-Rivest algorithm and we tried a lot of different things back at the time, read [1] Overall clickhouse reads blocks of fixed sizes (64k) and fi
9.
by danlark1 6y ago
That's a difficult question. As I am working at Google I need to consult each open source I want to publish on my behalf. This does not involve contributing to the list of the approved projects and telling about these contributions. If
10.
by danlark1 6y ago
For compiler-rt it is Apache 2.0 license https://github.com/llvm/llvm-project/blob/master/compiler-rt...
11.
by danlark1 6y ago
Hi, I thought that this is not the most interesting part of all the benchmarks, for example, all we need to test that with the quotient and the remainder: dividend = quotient * divisor + remainder, remainder < divisor and multiplication
12.
by danlark1 6y ago
Hi, I believe they can be done for 32 bit platforms also with the multiword division in Knuth https://skanthak.homepage.t-online.de/division.html what I've chosen for fallback if not x86_64 platform. I will try to impl
13.
by danlark1 6y ago
Hi everyone, the author is here. Yes, I believe the title should be changed to `Optimizing 128-bit Division` Yet, I was not expecting it to be here. Overall, I put some knowledge hidden in Hacker's Delight book, Knuth, GMP and GNU in t