Vir's blog — go fast with readable code!

there's too much unused parallelism on a single core

Shortcuts for WG21 content

14 Feb 2019

Since at least KDE 2, the runner (krunner - per default on Alt-F2) supports configurable prefixes that resolve to a URL that is then opened like kioclient5 exec would open them. I created the following shortcuts:

Read on …

Optimizing std::hypot for simd arguments

18 Jan 2019

Do you know about std::hypot(a, b) and std::hypot(a, b, c)? (The 3-argument overload exists since C++17, sometimes referred to as hypot3.) Why do the C and C++ standard libraries provide a function that is as simple as sqrt(a*a + b*b)? It doesn’t save enough characters to warrant its existence, right? Have you ever considered what happens if the input values are “very” small or large? Or if an input is an IEEE754 special value such as infinity or NaN? Have you ever considered how precise the calculation is, especially if an exact answer is obvious if one of the inputs is 0?

Read on …