It's hard to tune heavily tuned code.
Lisp has all the visual appeal of oatmeal with fingernail clippings mixed in.
A journey of a thousand miles continues with the second step.
Don't wear rollerskates to a tug-of-war.
The problem with using C++ ... is that there's already a strong tendency in the language to require you to know everything before you can do anything.
Perhaps you should compile your Perl with long doubles one of these megaseconds.