"bearophile" <bearophileh...@lycos.com> wrote in message news:h5hvhh$if...@digitalmars.com... > Jimbob Wrote: > >>bearophile: >> > And A^^3 may be faster than A*A*A when A isn't a simple number, so >> > always >> > replacing the >> > power with mults may be bad. >> >> It wont be on x86. Multiplication has a latency of around 4 cycles >> whether >> int or float, so x*x*x will clock around 12 cycles. The main instruction >> needed for pow, F2XM1, costs anywhere from 50 cycles to 120, depending on >> the cpu. And then you need to do a bunch of other stuff to make F2XM1 >> handle >> different bases. > > I don't understand what you mean. > But "when A isn't a simple number" means for example when A is a matrix.
Oops, my brain didnt parse what you meant by "simple number".
