D. J. Bernstein
Fast arithmetic


Frequently asked questions
The art of FFT benchmarking

How to install djbfft
Choices for conf-opt

Complex convolution library interface
Real convolution library interface


What is it?

djbfft is an extremely fast library for floating-point convolution. The current version holds most of the speed records for double-precision FFTs on general-purpose computers.

djbfft provides power-of-2 complex FFTs, real FFTs at twice the speed, and fast multiplication of complex arrays. Single precision and double precision are equally supported.

This work was supported by the National Science Foundation under grants DMS-9600083 and DMS-9970409. It is an application of my paper Multidigit multiplication for mathematicians, which presents every known technique for integer multiplication and every known technique for polynomial multiplication.