pub const POLY_BLOCK: usize = 256;Expand description
Number of lanes in one task of the closed-form polynomial kernels
(linear_roots_batch, quadratic_roots_batch, cubic_roots_batch).
rayon splits adaptively, so this is a lower bound on task granularity
rather than a fixed task size: it stops the splitter subdividing below a
block too small to pay for its own scheduling. A closed-form cubic solve is
on the order of tens of nanoseconds, so splitting down to a single equation
would spend more time in the scheduler than in Cardano’s formula.
The iterative solvers deliberately do not use a floor — see the module-level “Load imbalance” section.
This constant affects wall clock only. It cannot change any value, because every lane is computed independently of every other.
§Units
A count of polynomial equations, dimensionless.