Fast implementation/approximation of pow() function in C/C++

Question

I m looking for a faster implementation or good a approximation of functions provided by cmath.

I need to speed up the following functions

Answer 1

I recommend the routines in the book "Math Toolkit for Real-Time Programming" by Jack W. Crenshaw.

You might also want to post some of your code to show how you are calling these functions, as there may be some other higher level optimisation possibilities that are not apparent from the description given so far.