note

高速逆平方根（Fast Inverse Square Root）と“0x5f3759df”の正体 ...

高速逆平方根（Fast Inverse Square Root）は、Quake IIIで有名になったビットレベルの近似法です。0x5f3759dfというマジックナンバーで初期値を作り、ニュートン法1回で良好な精度を得ます。本稿ではその仕組みと、現代CPUのrsqrt命令との使い分けを簡潔に整理します。
GitHub

Fast Square Root (fsqrt)

A C++ implementation of a fast square root algorithm inspired by the famous "fast inverse square root" technique originally used in Quake III Arena. This project implements a high-performance square ...
IEEE

Solving for time-varying inverse square root by different ZD models based on different ...

Abstract: A novel class of neural dynamics, Zhang dynamics (ZD), has been recently proposed for online time-varying problem solving. The design method of ZD is based on an indefinite error-monitoring ...
IEEE

A fast FPGA based architecture for computation of square root and Inverse Square Root

Abstract: This study aims to design a fast FPGA based system for computation of the Square Root and Inverse Square Root values using modified Quake's algorithm. In this work, new seven magic numbers ...