[SciPy-dev] Cleaning zfft: first patch

[David Cournapeau]

Hi,

    I've just finished the first part of cleaning fftpack (only zfft for 
now; wanted to get dev feedback before implementing the scheme for 
everything). The patch is available as the ticket 408:

http://projects.scipy.org/scipy/scipy/ticket/408

    The patch consists in two part:
       - one part split each implementation out of zfft.c, to put it in 
zfft_name.c files, where name is the name of the backend (mkl, fftw, 
fftw3, etc...). The corresponding files have no #ifdef, etc... and 
should be easy to read/improve now.
       - the above source files are then used to generate a zfft.c file, 
through a python script. The main reason why I used python to generate 
the file instead of C macro is because I find this solution easier to 
add backend: adding a backend only consists in creating a new 
zfft_name.c file, and adding name to a python list in the python 
script.  Also, as the zfft.c is human readable and do not use new 
macros, it should be easy to read it now.
        - Regenerating the zfft.c file is only necessary when one of the 
backend source is changed, or when a new backend is added.

    Otherwise, it should work exactly as before; any change of behaviour 
with respect to configuring/compiling/running is a bug :) I've made no 
attempt for the python script to be pretty, too

    cheers,

    David