annotate fft/fftw/fftw-3.3.4/TODO @ 40:223f770b5341 kissfft-double tip

Try a double-precision kissfft
author Chris Cannam
date Wed, 07 Sep 2016 10:40:32 +0100
parents 26056e866c29
children
rev   line source
Chris@19 1 TODO before FFTW-$2\pi$:
Chris@19 2
Chris@19 3 * Wisdom: make it clear that it is specific to the exact fftw version
Chris@19 4 and configuration. Report error codes when reading wisdom. Maybe
Chris@19 5 have multiple system wisdom files, one per version?
Chris@19 6
Chris@19 7 * DCT/DST codelets? which kinds?
Chris@19 8
Chris@19 9 * investigate the addition-chain trig computation
Chris@19 10
Chris@19 11 * I can't believe that there isn't a closed form for the omega
Chris@19 12 array in Rader.
Chris@19 13
Chris@19 14 * convolution problem type(s)
Chris@19 15
Chris@19 16 * Explore the idea of having n < 0 in tensors, possibly to mean
Chris@19 17 inverse DFT.
Chris@19 18
Chris@19 19 * better estimator: possibly, let "other" cost be coef * n, where
Chris@19 20 coef is a per-solver constant determined via some big numerical
Chris@19 21 optimization/fit.
Chris@19 22
Chris@19 23 * vector radix, multidimensional codelets
Chris@19 24
Chris@19 25 * it may be a good idea to unify all those little loops that do
Chris@19 26 copying, (X[i], X[n-i]) <- (X[i] + X[n-i], X[i] - X[n-i]),
Chris@19 27 and multiplication of vectors by twiddle factors.
Chris@19 28
Chris@19 29 * Pruned FFTs (basically, a vecloop that skips zeros).
Chris@19 30
Chris@19 31 * Try FFTPACK-style back-and-forth (Stockham) FFT. (We tried this a
Chris@19 32 few years ago and it was slower, but perhaps matters have changed.)
Chris@19 33
Chris@19 34 * Generate assembly directly for more processors, or maybe fork gcc. =)
Chris@19 35
Chris@19 36 * ensure that threaded solvers generate (block_size % 4 == 0)
Chris@19 37 to allow SIMD to be used.
Chris@19 38
Chris@19 39 * memoize triggen.