A 40-page Bachelor’s degree thesis on the legendary bit-hacking Quake III Q_rsqrt() implementation (via redacted):
This function, commonly called InvSqrt, approximates the inverse (or reciprocal) square root of a 32-bit floating point number very quickly. It can be found in many open source libraries and games on the Internet, such as the C source code for Quake III: Arena. This raises many questions. Why is it needed? Who wrote it? How does it work? How well does it work? Is it still useful with modern processors today? And finally, can it be improved to work better? This thesis will examine those questions and give a unique interpretation and optimization of the function itself.
an OSS clone of a Pinboard-style bookmark service. ‘designed be to be minimal, fast, and easy to set up using Docker.’ Bookmarking for emergency use only; if anything happens to Pinboard.in, I’ll have this to fall back to. (via dahamsta)