[PATCH] Optimize x*x*x*x*x*x using 3 multiplications.

[Paolo Carlini]

Geoff Keating wrote:

>which, since real arithmetic is associative, is exactly the same as
>the previous answer.
>
Eh!
I wonder (thanks Craig for your private message), what happens if we 
work in probabilistic setting, that is, computing means and statistics 
wrt the (joint) distributions not just bounding... perhaps this is the 
logic behind the Ada83 and Ada95 choices??

Paolo.