pub(crate) static P_TIMES_16_HI: u32x8
The high limbs of (16p, 16p, 16p, 16p), so that
(16p, 16p, 16p, 16p) = [P_TIMES_16_LO, P_TIMES_16_HI, P_TIMES_16_HI, P_TIMES_16_HI, P_TIMES_16_HI]