Comments about FFT PATCH ready



?iga Lenar?i? wrote:
>
>
> It works nicely with 'flonum', yes. I changed it to use add and mul,
> added your changes from CVS, used flonum instead of double-float...
> See the attached file.
>
I didn't mean to imply that you should make the changes, but thanks!

There is one other issue.  The FFT routine uses pi, which is a
long-float.  We need to fix that.  However, with cmucl's
double-double-float type, pi is not a double-double-float, so we'd have
to adjust for that.

As a quick check, I tried the original fft on a 8K input.  It takes 1.6
sec, of which 1.09 is spent just in $fft.  fft-dif-internal takes just
0.15 sec.

With your latest code, that same test takes 0.11 sec, of which 0.06 is
spent in fft+ifft-common, and fft-dif-internal takes just 0.01.

(Yes, this is near the limit of granularity, but it does give a rough
indication.)

Ray