FLINT3.7.0-dev
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_radix_mulmid_fft_length

Synopsis#include <flint/radix.h>
slong _radix_mulmid_fft_length(slong an, slong bn, slong lo, slong hi)source

The length of the convolution that radix_mulmid_fft_small computes for the window [lo,hi)[\mathit{lo}, \mathit{hi}), used by radix_mulmid to choose the algorithm: with an′\mathit{an}' and bn′\mathit{bn}' the numbers of limbs of the operands that reach the window, it is min⁡(an′,bn′)+(hi′−lo′)\min(\mathit{an}', \mathit{bn}') + (\mathit{hi}' - \mathit{lo}') if the window (clipped to the product) is shorter than max⁡(an′,bn′)\max(\mathit{an}', \mathit{bn}'), and an′+bn′\mathit{an}' + \mathit{bn}' otherwise; 0 for an empty window.

Cite this page

The FLINT team, “_radix_mulmid_fft_length (radix.h),” FLINT: Fast Library for Number Theory, documentation, version 3.7.0-dev, 2026. https://flintlib.org/doc/radix/_radix_mulmid_fft_length.html (generated 2026-11-02).