Given the amount of discussion this article has sparked on HN, I’d argue that as obvious as it might be, the technique is nonetheless obscure. The amount of highly experienced and accomplished programmers I’ve encountered who have no idea how floating point numbers work is astoundingly high.

If a similar article were written about how shifting an integer to the right by one bit is equivalent to dividing it by two, I highly suspect it would attract no attention on this site, aside from a couple dismissive comments grousing about why such a basic fact needs its own article.

You can of course have some idea how floating point numbers work, but still not know how to bit twiddle abs().

I don't know what to take from the fact that Java stdlib didn't use it until Java 18? It does seem like it wasn't obvious to at least someone who knew something.

> If a similar article were written about how shifting an integer to the right by one bit is equivalent to dividing it by two, I highly suspect it would attract no attention on this site,

Nah, it would be full of comments of people saying "well of course I knew that! doesn't everyone who's anyone? I can't believe how many newbies don't though!" :)