Communications of the ACM
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How the “Frontier” Became the Slogan of Uncontrolled AI
Artificial intelligence (AI) has been billed as the next frontier of humanity: the newly available expanse whose exploration …
From Daniel Lemire's Blog
Sentinels can be faster
A standard trick in programming is to use “sentinel values”. These are special values that represent metadata efficiently. The C language represents strings asContinue...
From Daniel Lemire's Blog
Science and Technology links (August 29th 2020)
In children, higher video game time is positively associated with cognition (i.e., kids who play more video games are smarter). Note that it does not follow that...
From Daniel Lemire's Blog
Science and Technology links (August 9th 2020)
The BBC reports that diversity and anti-bias training is of little use and may even be counterproductive if the goal is reduce biases: “The effect of bias training...
From Daniel Lemire's Blog
Performance tip: constructing many non-trivial objects is slow
I started programming professionally when Java came out and right about when C++ was the “hot new thing”. Following the then-current fashion, I looked down at C...
From Daniel Lemire's Blog
Science and Technology links (August 1st 2020)
In Japan, a large dam is being constructed almost entirely by robots. Naked mole rats are mammals that do not age in the sense that their fitness and mortalityContinue...
From Daniel Lemire's Blog
Science and Technology links (July 25th 2020)
I was taught that human beings only arrived to America recently (15,000 years ago). It turns out that it is wrong. There were human beings in America 30,000 years...
From Daniel Lemire's Blog
Avoid character-by-character processing when performance matters
When processing strings, it is tempting to view them as arrays of characters (or bytes) and to process them as such. Suppose that you would like to determine whether...
From Daniel Lemire's Blog
Downloading files faster by tweaking headers
I was given a puzzle recently. Someone was parsing JSON files downloaded from the network from a bioinformatics URI. One JSON library was twice as fast at the other...
From Daniel Lemire's Blog
The cost of runtime dispatch
For high-performance software, it is sometimes needed to use different functions, depending on what the hardware supports. You might write different functions,Continue...
From Daniel Lemire's Blog
Science is the belief in the ignorance of experts
Science is the belief in the ignorance of experts said Richard Feynman. Feynman had a Nobel prize in physics. He was a remarquable educator: his lecture notes are...
From Daniel Lemire's Blog
Science and Technology links (July 11th 2020)
Some upcoming Mercedes cars will have augmented reality head-up displays. Intel’s new standard for high-speed cables (thunderbolt) supports 3 GB/s bandwidth. (This...
From Daniel Lemire's Blog
GNU GCC does not round floating-point divisions to the nearest value
I know that floating-point arithmetic is a bit crazy on modern computers. For example, floating-point numbers are not associative: 0.1+(0.2+0.3) == 0.599999999999999978...
From Daniel Lemire's Blog
Science and Technology links (June 20th 2020)
UCLA researchers have achieved widespread rejuvenation in old mice through blood plasma diluation, a relatively simple process. (…) these results establish broad...
From Daniel Lemire's Blog
Computational overhead due to Docker under macOS
For my programming work, I tend to assume that I have a Linux environnement. That is true whether I am under Windows, under macOS or under a genuine Linux. HowContinue...
From Daniel Lemire's Blog
Reusing a thread in C++ for better performance
In a previous post, I measured the time necessary to start a thread, execute a small job and return. auto mythread = std::thread([] { counter++; }); mythread.join...
From Daniel Lemire's Blog
Science and Technology links (June 6th 2020)
A small number of people are responsible for a disproportionate number of inventions and innovations. Why are these people different? Using neuroimaging techniques...
From Daniel Lemire's Blog
How Innovation Works (book review)
I read How Innovation Works by Matt Ridley in a few hours. It is a delicious book. Ridley distinguishes invention from innovation. The inventor creates something...
From Daniel Lemire's Blog
The Go compiler needs to be smarter
One of my favorite languages is the Go language. I love its simplicity. It is popular and useful in a cloud setting. Many popular tools are written in Go, and for...
From Daniel Lemire's Blog
Science and Technology links (May 30th 2020)
We might soon be able to buy memory cards with speeds nearing 4 GB/s. For comparison, an expensive and recent macBook currently has a disk with a 2 GB/s bandwidth...
From Daniel Lemire's Blog