cannam@167: Previous: Cycle Counters, Up: Installation and Customization [Contents][Index]
cannam@167:The directory genfft contains the programs that were used to
cannam@167: generate FFTW’s “codelets,” which are hard-coded transforms of small
cannam@167: sizes.
cannam@167:
cannam@167: We do not expect casual users to employ the generator, which is a rather
cannam@167: sophisticated program that generates directed acyclic graphs of FFT
cannam@167: algorithms and performs algebraic simplifications on them. It was
cannam@167: written in Objective Caml, a dialect of ML, which is available at
cannam@167: http://caml.inria.fr/ocaml/index.en.html.
cannam@167:
cannam@167:
If you have Objective Caml installed (along with recent versions of
cannam@167: GNU autoconf, automake, and libtool), then you
cannam@167: can change the set of codelets that are generated or play with the
cannam@167: generation options. The set of generated codelets is specified by the
cannam@167: {dft,rdft}/{codelets,simd}/*/Makefile.am files. For example, you can add
cannam@167: efficient REDFT codelets of small sizes by modifying
cannam@167: rdft/codelets/r2r/Makefile.am.
cannam@167:
cannam@167: After you modify any Makefile.am files, you can type sh
cannam@167: bootstrap.sh in the top-level directory followed by make to
cannam@167: re-generate the files.
cannam@167:
We do not provide more details about the code-generation process, since cannam@167: we do not expect that most users will need to generate their own code. cannam@167: However, feel free to contact us at fftw@fftw.org if cannam@167: you are interested in the subject. cannam@167:
cannam@167: cannam@167:You might find it interesting to learn Caml and/or some modern cannam@167: programming techniques that we used in the generator (including monadic cannam@167: programming), especially if you heard the rumor that Java and cannam@167: object-oriented programming are the latest advancement in the field. cannam@167: The internal operation of the codelet generator is described in the cannam@167: paper, “A Fast Fourier Transform Compiler,” by M. Frigo, which is cannam@167: available from the FFTW home page and also cannam@167: appeared in the Proceedings of the 1999 ACM SIGPLAN Conference on cannam@167: Programming Language Design and Implementation (PLDI). cannam@167:
cannam@167:cannam@167: Previous: Cycle Counters, Up: Installation and Customization [Contents][Index]
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