3 ms·

When I read his 'discovery' of fast modulo division [1], it immediately reminded me of the same technique discussed as an aside in this very interesting [2006]

When I read his 'discovery' of fast modulo division [1], it immediately reminded me of the same technique discussed as an aside in this very interesting [2006] IBM SIMD paper [2]. I let him know about this and he added the last footnote in [1], but no update of his blog or related github page saying "hah, turns out this was a known method at least in IBM'. It left a slight bad impression in my mind. So, yeah .. [1]: https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-modulo-reduction/ https://lemire.me/blog/2016/06/27/a-fast-alternative-to-the-... See "2 Outline of Approach" section, last 2 paragraphs: [2]: https://dominoweb.draco.res.ibm.com/reports/rc24100.pdf https://dominoweb.draco.res.ibm.com/reports/rc24100.pdf

deleted 6y ago
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teraflop 6y ago
Why did you put "discovery" in quotes, even though Lemire doesn't claim anywhere in that blog post to have discovered or invented the technique?
- eternalban 6y ago
  That's a fair point. Generally I am used to seeing a cite of original source on an elaboration, proof, or "let's dig into how it works" sort of writeups on algorithmic approaches. (Sometimes this is done even when the algorithm in question and source is well known.) Specially if the author is an academic.
- ggrrhh_ta 6y ago
  Well; I read the blog post and I am disappointed at Lemire, actually. Yes, it does not claim anywhere it is his invention - it starts the description of the algorithm with "The common solution", but if you read it, it really looks like the development of the technique as a whole is his; at the end one note says: "The technique described in this blog post is in used within Microsoft Arriba." If no one had pointed out that it is not his, I would have thought that it was his, the blog post title is "A fast alternative to the fast modulo reduction", and not "How X's algorithm for fast modulo reduction works. My implementation".

deleted 6y ago

[deleted]

teraflop 6y ago

Why did you put "discovery" in quotes, even though Lemire doesn't claim anywhere in that blog post to have discovered or invented the technique?

eternalban 6y ago
That's a fair point. Generally I am used to seeing a cite of original source on an elaboration, proof, or "let's dig into how it works" sort of writeups on algorithmic approaches. (Sometimes this is done even when the algorithm in question and source is well known.) Specially if the author is an academic.
ggrrhh_ta 6y ago
Well; I read the blog post and I am disappointed at Lemire, actually. Yes, it does not claim anywhere it is his invention - it starts the description of the algorithm with "The common solution", but if you read it, it really looks like the development of the technique as a whole is his; at the end one note says: "The technique described in this blog post is in used within Microsoft Arriba." If no one had pointed out that it is not his, I would have thought that it was his, the blog post title is "A fast alternative to the fast modulo reduction", and not "How X's algorithm for fast modulo reduction works. My implementation".