each limb at the least significant position, shifting all // previous limbs left by _W. This way each limb will get shifted by the // correct number of bits. We can insert at least N - 1 limbs without // overflowing m. After that, we need to reduce every time we shift. i := len(x.limbs) - 1 // For the first N - 1 limbs we can skip the actual shifting and position // them at the shifted position, which starts at min(N - 2, i). start := len(m.nat.limbs) - 2 if i < start { start = i } for j := start;...