This is the official repository for the FFTW Fourier transform library, version 3.x
C OCaml C++ Makefile M4 Perl Shell
Latest commit 102f2fd Feb 22, 2017 @matteo-frigo matteo-frigo Compute mflops() in 64 bit precision
Old code was overflowing for N>2^32
Failed to load latest commit information.
api add __cdecl decorators to fftw3.h functions on Windows Jan 22, 2017
dft Cast Police Jun 4, 2016
doc Improve documentation of fftw_make_planner_thread_safe Jan 16, 2017
genfft Warnings Police Jan 15, 2017
kernel Ansi C Police Jan 15, 2017
libbench2 Compute mflops() in 64 bit precision Feb 22, 2017
m4 Added Power8 VSX SIMD support Mar 28, 2015
mpi Fix scrips that generate the MPI F03 interface Jan 27, 2017
rdft Integral Type Police Jun 5, 2016
reodft copyright year update Mar 4, 2014
simd-support Revert simd-avx.h changes from b606e31 Jan 7, 2017
support Fixes for Windows cross-compilation Jul 30, 2016
tests Warnings Police Jan 15, 2017
threads Warnings Police Jan 15, 2017
tools fix #29 Jan 30, 2015
.gitignore Make 128/256 bit generic simd separate options Apr 8, 2015
AUTHORS update AUTHORS Jul 30, 2016
CONVENTIONS added K Mar 2, 2003
COPYING Store GPLv2 in darcs because automake installs GPLv3 these days. Nov 5, 2008
COPYRIGHT copyright year update Mar 4, 2014 Assert that CURRENT-AGE=3 Jan 16, 2017
NEWS Update NEWS for 3.3.6-pl2 Jan 27, 2017
README mention and summarize the build process in (closes Jan 25, 2017 mention and summarize the build process in (closes Jan 25, 2017
TODO Fix SIMD autodetection Jul 30, 2016 Use ocamlbuild for building genfft May 8, 2011 note that these scripts are not meant for normal users Mar 17, 2013 Get ready for fftw-3.3.6-pl2 Jan 27, 2017 make -lm a private library in Dec 4, 2012 update AUTHORS Jul 30, 2016


This is the git repository for the FFTW library for computing Fourier transforms (version 3.x), maintained by the FFTW authors.

Unlike most other programs, most of the FFTW source code (in C) is generated automatically. This repository contains the generator and it does not contain the generated code. You cannot compile code from this repository unless you have special tools and know what you are doing.

Most users should ignore this repository, and should instead download official tarballs from, which contain the generated code, do not require any special tools or knowledge, and can be compiled on any system with a C compiler.

Advanced users and FFTW maintainers can obtain code from github and run the generation process themselves. This is a long process that requires special tools. See README for details. (Summary: in addition to the usual Unix developer software, you need GNU autotools and OCaml. Then you can run sh to compile FFTW and generate .tar.gz files similar to the official releases.)