[gmx-developers] Inverse Square Root code in Gromacs

[Haiqing Zhao]

Hi, all,
Maybe this is such a small question since I'm new to Gromacs. sorry for spam.

It is said that Gromacs has very efficient algorithm to calculate the square root. I serached the manual. And in Page227, it sounds like look-up tables &Newton Iteration were still used as other traditional algorithms did. I don't know if i got the right point? Could anybody give me some guide, or help me to find the source code of the Inverse Square Root?

(By the way, another result of my search is the other fast inverse square root method, from  http://en.wikipedia.org/wiki/Fast_inverse_square_root)

Thank you so much!
haiqing