Integer Overflow Checking Cost (danluu.com)
30 points by iwsk 2 days ago
tcfhgj 2 hours ago
Definitely cheaper than using Electron I would say
mayoff 2 hours ago
In Swift (Apple’s C++ successor), the normal operators (`+`, `-`, `*`) trap on overflow for integer types. If you want twos complement wrapping, you can use `&+`, `&-`, and `&*`.
Given that Apple has been making its own CPU cores for years now, I suspect overflowing checking on Apple CPUs is virtually free (aside from code size).
qayxc 19 minutes ago
> Given that Apple has been making its own CPU cores for years now, I suspect overflowing checking on Apple CPUs is virtually free (aside from code size).
Never make guesses based on a particular programming language. In Apple's own C documentation (https://developer.apple.com/documentation/xcode/integer-over...) it is stated that "Overflows result in undefined behavior." and enabling wrapping behaviour "may adversely impact performance", indicating that overflow detection is in fact not "virtually free".
saagarjha 16 minutes ago
Code size (and branch table entries) are not free, of course. The other thing to note is that trapping operators often need to trap precisely which can lead to missed optimizations.
gnabgib 2 days ago
2014 (probably? Or 2008. Old and no date) Previously (166 points, 2014, 107 comments) https://news.ycombinator.com/item?id=8765714
zahlman 2 days ago
Resubmitting it seems timely, given recent Linux kernel news (e.g. https://lwn.net/Articles/1065889/).
aw1621107 3 hours ago
The archive says "12/14", so 2014 seems about right.
ardline 3 hours ago
[flagged]