Computing Integer Powers in Floating-Point Arithmetic
Peter Kornerup, Vincent Lefèvre, Jean‐Michel Muller · 2018 52nd Asilomar Conference on Signals, Systems, and Computers · 2007
We introduce two algorithms for accurately evaluating powers to a positive integer in floating-point arithmetic, assuming a fused multiply-add (fma) instruction is available. We show that our log-time algorithm always produce faithfully-rounded results, discuss the possibility of getting correctly rounded results, and show that results correctly rounded in double precision can be obtained if extended precision is available with the possibility to round into double precision (with a single rounding).