pretty happy with radix 2 and radix 4  next up is radix 3, or maybe 5
pretty happy with radix 2 and radix 4
 next up is radix 3, or maybe 5

sf-is-evil/kissfft,sf-is-evil/kissfft,pemryan/kissFFT,pemryan/kissFFT,pemryan/kissFFT,sf-is-evil/kissfft,sf-is-evil/kissfft,pemryan/kissFFT