pub const T0: [u32; 256];Expand description
T0[x] = (2·S(x), S(x), S(x), 3·S(x)), row 0 in the low byte.
Row j of a column uses T0[x].rotate_left(8 * j).
256 entries × 32 bits = 1 KiB. It is the contents of every
DualTableRom port. Why it exists: one lookup returns an S-box result
already multiplied by every MixColumns coefficient it will ever need, so a
table round needs no separate S-box and almost no MixColumns logic.