Efficient Square Root Computation

bit shift to right/left is a fast binary division/multiplication by 2, division by 4 inside the sqrt means multiplication by 2 outside the sqrt, to get the sqrt value in the tabulated [0,1] 2nd order derivative hermite interpolation range. ie sqrt(a*4)=sqrt(a)*2 where a is in the [0,1] range. Same for inverse square root for multiplication operation, or just for division operation.