NEWS

FFTW 3.0

Major goals of this release:

* Speed: often 20% or more faster than FFTW 2.x, even without SIMD (see below).

* Complete rewrite, to make it easier to add new algorithms and transforms.

* New API, to support more general semantics.

Other enhancements:

* SIMD acceleration on supporting CPUs (SSE, SSE2, 3DNow!, and AltiVec).
 (With special thanks to Franz Franchetti for many experimental prototypes
  and to Stefan Kral for the vectorizing generator from fftwgel.)

* True in-place 1d transforms of large sizes (as well as compressed
  twiddle tables for additional memory/cache savings).

* More arbitrary placement of real & imaginary data, e.g. including
  interleaved (as in FFTW 2.x) as well as separate real/imag arrays.

* Efficient prime-size transforms of real data.

* Multidimensional transforms can operate on a subset of a larger matrix.

* By popular demand, simultaneous linking to double precision (fftw),
  single precision (fftwf), and long-double precision (fftwl) versions
  of FFTW is now supported.

* Cycle counters (on all modern CPUs) are exploited to speed planning.

* Efficient transforms of real even/odd arrays, a.k.a. discrete
  cosine/sine transforms (types I-IV).  (Currently work via pre/post
  processing of real transforms, ala FFTPACK, so are not optimal.)

* DHTs (Discrete Hartley Transforms), again via post-processing
  of real transforms (and thus suboptimal, for now).

* Support for linking to just those parts of FFTW that you need,
  greatly reducing the size of statically linked programs when
  only a limited set of transform sizes/types are required.

* Canonical global wisdom file (/etc/fftw/wisdom) on Unix, along
  with a command-line tool (fftw-wisdom) to generate/update it.

* Authors' good looks have greatly improved with age.