Fast polynomial multiplication

Stream: Is there code for X?

[Geoffrey Irving]

Does anyone have fast polynomial ring code, using Toom-Cook or similar (or faster) for multiplication?

Motivation: I have 2^27 coefficients of the Mandelbrot Bottcher series from a while ago via GPUs and FFTs (https://github.com/girving/mandelbrot), and now that I have Gronwall’s area theorem (https://github.com/girving/ray/blob/a3c9424223eba1bfc28bd6fff2e8933ecc9087a6/Ray/Koebe/Gronwall.lean#L1185) I’m vaguely tempted to do the same in Lean for a smaller number of terms to compare. If one rescales a bit the calculations can be done exactly as integer series.