What Daniel Lemire thinks about software performance
Computer science professor who works on fast data processing; co-author of the simdjson parser and a weekly blogger about software performance since 2004.
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We collected these quotes from things they published elsewhere, and every quote links to where it was said. They have no account here and have not endorsed this site. Quotes are word for word; the short line under each one is our own restatement, not their wording. Their own site. Is this you? Claim it or ask us to remove it. Or tell us what is wrong here.
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4 dated positions, 2026, in their own words. Our reading of what Daniel Lemire has said — not written or endorsed by them.
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Our readingCompressed bitmaps are not always better than uncompressed ones; there are many tradeoffs.
Their wordsCompressed bitmaps like Roaring are not always better. There are many tradeoffs.
- 4 weeks earlier
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Their wordsNEON has nothing like it; on x64, the closest thing is the SSE4.2 string-comparison instructions (pcmpistrm), which are slow.
- 2 days earlier
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Their wordsIn many practical cases, the new std::flat_map is a better alternative to the std::map.
- 1 day earlier
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Their wordsThus it appears that on the latest AMD and ARM processors subnormals might not be a concern. But they remain very much a performance issue under Intel processors.
↗Subnormal floating-point numbers are expensive… on Intel processorslemire.me