fftw-wisdom-to-conf - generate FFTW wisdom (pre-planned transforms)
fftw-wisdom-to-conf [< INPUT] [> OUTPUT]
fftw-wisdom-to-conf is a utility to generate C configuration routines
from FFTW wisdom files, where the latter contain saved information
about how to optimally compute (Fourier) transforms of various sizes.
A configuration routine is a C subroutine that you link into your
program, replacing a routine of the same name in the FFTW library, that
determines which parts of FFTW are callable by your program.
The reason to do this is that, if you only need transforms of a limited
set of sizes and types, and if you are statically linking your program,
then using a configuration file generated from wisdom for those types
can substantially reduce the size of your executable. (Otherwise,
because of FFTW’s dynamic nature, all of FFTW’s transform code must be
linked into any program using FFTW.)
FFTW is a free library to compute discrete Fourier transforms in one or
more dimensions, for arbitrary sizes, and of both real and complex
data, among other related operations. More information on FFTW can be
found at the FFTW home page: http://www.fftw.org
fftw-wisdom-to-conf reads wisdom from standard input and writes the
configuration to standard output. It can easily be combined with the
fftw-wisdom tool, for example:
fftw-wisdom -n cof1024 cob1024 -o wisdom
fftw-wisdom-to-conf < wisdom > conf.c
will create a configuration "conf.c" containing only those parts of
FFTW needed for the optimized complex forwards and backwards out-of-
place transforms of size 1024 (also saving the wisdom itself in
Alternatively, you can run your actual program, export wisdom for all
plans that were created (ideally in FFTW_PATIENT or FFTW_EXHAUSTIVE
mode), use this as input for fftw-wisdom-to-conf, and then re-link your
program with the resulting configuration routine.
Note that the configuration routine does not contain the wisdom, only
the routines necessary to implement the wisdom, so your program should
also import the wisdom in order to benefit from the pre-optimized
Display help on the command-line options and usage.
Print the version number and copyright information.
Send bug reports to firstname.lastname@example.org.
Written by Steven G. Johnson and Matteo Frigo.
Copyright (c) 2003, 2007-8 Matteo Frigo
Copyright (c) 2003, 2007-8 Massachusetts Institute of Technology