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lemire
Code-used-on-Daniel-Lemire-s-blog
C++2012–2026
lemire / Code-used-on-Daniel-Lemire-s-blog

Code-used-on-Daniel-Lemire-s-blog

This is a repository for the code posted on my blog

Explore on GitHubRead Hacker News discussions
21Distinct people
23Mentions
0Explicit recommenders
970GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

This is a repository for the code posted on my blog

GitHub

Where it is used

No documented product use was verified in the last source check.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

No other repository is repeatedly linked in the same discussions.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year23 dated mentions

Observed mentions: 2012-07-24 00:16:38 UTC to 2026-05-23 10:17:41 UTC.

012342012-01-01 00:00:00 UTC to 2013-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments20122013-01-01 00:00:00 UTC to 2014-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2014-01-01 00:00:00 UTC to 2015-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2015-01-01 00:00:00 UTC to 2016-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2016-01-01 00:00:00 UTC to 2017-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2017-01-01 00:00:00 UTC to 2018-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2018-01-01 00:00:00 UTC to 2019-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments20192020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments2023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 4 mentions; 0 submissions, 4 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20122012-01-01 00:00:00 UTC2013-01-01 00:00:00 UTC202
20132013-01-01 00:00:00 UTC2014-01-01 00:00:00 UTC000
20142014-01-01 00:00:00 UTC2015-01-01 00:00:00 UTC000
20152015-01-01 00:00:00 UTC2016-01-01 00:00:00 UTC000
20162016-01-01 00:00:00 UTC2017-01-01 00:00:00 UTC202
20172017-01-01 00:00:00 UTC2018-01-01 00:00:00 UTC000
20182018-01-01 00:00:00 UTC2019-01-01 00:00:00 UTC101
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC404
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC101
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC404
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC101
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC404
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC303
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC000
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC101

What Hacker News says

23 sources
mustache_kimono·Sep 28, 2024
> Migrating a Python script to C++ could well be worthwhile in some instances. However, it’s not all sunshine and rainbows with C++. Diving into C++ requires more mental effort. That's a non-trivial statement! A statement which makes this article seem like it was written 10 years ago. Did anyone believe the C++ cited is all the C++ required to make this work? Go see the C++ as tested: https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/... By this I mean -- if Python isn't fast enough -- isn't that why we have Rust? Compare to my quick Rust: https://play.rust-lang.org/?version=stable&mode=debug&editio... It kinda crushes the CLI tool use case. Especially w/r/t JSON.
In It is never too late to write your own C/C++ command-line utilities
eesmith·Aug 21, 2023
You should also worry about how other peoples' time is wasted when you miss important details then comment about easily assuaged worries. Quoting the article "I use GCC 11 on an Ice Lake server. My source code is available.", linking to https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/... . From the README at the top-level: > Unless otherwise stated, I make no copyright claim on this code: you may consider it to be in the public domain. > Don't bother forking this code: just steal it.
In Transcoding Latin 1 strings to UTF-8 strings at 12 GB/s using AVX-512
morelisp·Jul 2, 2023
> omits the massively expensive calendar conversion step Is that not included in what's 6x faster? I agree comparing against strptime is a bit of a gimme and a scalar fixed-format parser would be fairer, but I'm pretty sure it will beat that too. Edit to reply since rate-limited: > No mention of calendar in either place. Did you see something in the article or code, or are you just asking us to check? The (lack so far of) calendar is mentioned in the blog post - "It does not get all the parsing done... We can just use standard C code for the result." - and is very obviously in the GitHub code. https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/...
In Parsing time stamps faster with SIMD instructions
brigade·Mar 18, 2021
The blog post links to the benchmark... It's repeatedly populating a 20k entry array with the results. godbolt clang compiles it to: .LBB5_2: // =>This Inner Loop Header: Depth=1 mul x13, x11, x10 umulh x14, x11, x10 eor x13, x14, x13 mul x14, x13, x12 umulh x13, x13, x12 eor x13, x13, x14 str x13, [x0, x8, lsl #3] add x8, x8, #2 // =2 cmp x8, x1 add x11, x11, x9 b.lo .LBB5_2 [1] https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/...
In Apple’s M1 processor and the full 128-bit integer product
canucker2016·Feb 22, 2021
Based on the title, I thought you were Daniel Lemire with another writeup for benchmarking character conversion of some sort - for examples see https://hn.algolia.com/?q=lemire.me. Great work on reducing the size of the character conversion tables, but I don't see any evidence for the title of the web page. "Compact character case conversion" is more appropriate currently based on the data given in the readme. Data can be greatly compressed at the cost of access speed or the compressed data could speed up data access - with x86 CPU complexity these days, I wouldn't bet on determining the speed based on a quick glance of the code. You state the case conversion is fast, yet I don't see any benchmarks backing up the assertion. I'd expect a few different types of input to be benchmarked - ASCII upper/lower case alphabet chars (typical A-Z,a-z
Read the rest
& space/punctuation thrown in to make it look like typical written language text inputs), Unicode upper/lower case et al., and random characters. Not gonna leave people in the lurch though - Daniel Lemire has a recent post which can be used as a scaffold for benchmarking. Code: https://github.com/lemire/Code-used-on-Daniel-Lemire-s-blog/... Post: https://lemire.me/blog/2021/02/09/on-the-cost-of-converting-... If the code is to be timed on Windows, the code will need a Windows version of "clock_gettime(CLOCK_REALTIME, ...)" - see https://stackoverflow.com/questions/5404277/porting-clock-ge...
In Fast character case conversion, or how to really compress sparse arrays

Showing the 15 most recent of 23 sources. Enable JavaScript to search and browse every indexed mention.

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