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
Passing integers by reference can be expensive…
In languages like C++, you can pass values to functions in two ways. You can pass by value: the value is semantically “copied” before being passed to the function...
From Daniel Lemire's Blog
Science and Technology links (August 31st 2019)
The Conboy laboratory in Berkeley is responsible for some of the best work in aging research. In 2005, they showed that by connecting the blood vessels of an old...
From Daniel Lemire's Blog
How fast can scancount be?
In an earlier post, I described the following problem. Suppose that you have tens of arrays of integers. You wish to find all integer that are in more than 3 (say)...
From Daniel Lemire's Blog
Science and Technology links (August 24th 2019)
The net contribution of the Amazon ecosystem to the world’s oxygen is effectively zero. Furthermore, there is a lot of oxygen in the air and it would be excessively...
From Daniel Lemire's Blog
Science and Technology links (August 17th 2019)
Google may soon release an augmented-reality version of Google Maps for mobile phones. I have always found it difficult to identify the streets I see in an unfamiliar...
From Daniel Lemire's Blog
Faster threshold queries with cache-sensitive scancount
Suppose that you are given 100 sorted arrays of integers. You can compute their union or their intersection. It is a common setup in data indexing: the integers...
From Daniel Lemire's Blog
Science and Technology links (August 10th 2019
A short (less than one hour) online lesson improved grades among weaker students. The lesson taught the growth mindset: that intellectual abilities can be developed...
From Daniel Lemire's Blog
Science and Technology links (August 3rd 2019)
Reportedly, researchers in China are creating embryos that are part human and part monkey. Sickle cell disease is a genetic disease with no cure. In an attemptContinue...
From Daniel Lemire's Blog
JSON parsing: simdjson vs. JSON for Modern C++
JSON is the ubiquitous data format on the Internet. There is a lot of JSON that needs to be parsed and validated. As we just released the latest version of ourContinue...
From Daniel Lemire's Blog
A new release of simdjson: runtime dispatching, 64-bit ARM support and more
JSON is a ubiquitous data exchange format. It is found everywhere on the Internet. To consume JSON, software uses tools called JSON parsers. Earlier this year,Continue...
From Daniel Lemire's Blog
Science and Technology links (July 27th 2019)
There are thick ice deposits on the Moon. Water in space is important as it can be used to create fuel and to sustain life. Most animals do not suffer heart attacks...
From Daniel Lemire's Blog
How fast can a BufferedReader read lines in Java?
In an earlier post, I asked how fast the getline function in C++ could run through the lines in a text file. The answer was about 2 GB/s. That is slower than some...
From Daniel Lemire's Blog
Programming competition with $1000 in prizes: make my code readable!
Colm MacCárthaigh is organizing a programming competition with three 3 prizes: $500, $300, $200. The objective? Produce the most readable, easy to follow, and well...
From Daniel Lemire's Blog
Arbitrary byte-to-byte maps using ARM NEON?
Modern processors have fast instructions that can operate on wide registers (e.g., 128-bit). ARM processors, the kind of processors found in your phone, have such...
From Daniel Lemire's Blog
Science and Technology links (July 20th 2019)
Researchers solve the Rubik’s cube puzzle using machine learning (deep learning). There has been a rise in the popularity of “deep learning” following some major...
From Daniel Lemire's Blog
Science and Technology links (July 13th 2019)
Drinking juice increases your risk of having cancer. College completion rates are increasing and this may have to do with lower standards. Australia is going to...
From Daniel Lemire's Blog
Parsing JSON quickly on tiny chips (ARM Cortex-A72 edition)
I own an inexpensive card-size ROCKPro64 computer ($60). It has a ARM Cortex-A72 processors, the same processors you find in the recently released Raspberry PiContinue...
From Daniel Lemire's Blog
Parsing JSON using SIMD instructions on the Apple A12 processor
Most modern processors have “SIMD instructions“. These instructions operate over wide registers, doing many operations at once. For example, you can easy subtract...
From Daniel Lemire's Blog
Science and Technology links (July 6th, 2019)
Jim Keller, the vice president of silicon engineering at Intel, is optimistic regarding the continued exponential progress in computing: “It’s going to keep going...
From Daniel Lemire's Blog