Has been looking at different methods like using a look-up table or double-dabble, but have up to this moment not found any algoritm that do the work most effectively. The 64 bit value is delivered to the routine in two 32 bits registers (upper,lower). I am writing a larger project for PIC 32 microcontroller, and have already made a large library for this controller in MIPS, so I know basic MIPS.