Qrc.Gf_256Arithmetic over galois field GF(28).
The type for degree 8 polynomials, using 0x1FF bits. The ith zero-based bit index represents the coefficient (0 or 1) of the ith degree variable.
log f x is y the base g logarithm of x, i.e. gy = x. This is 255 if x = 0.