Are you aware that your linux perl is using long doubles?

I don't think it is. For the expression presented in the original post in this thread, on linux (without long double support) I get the same -95.2443654287109, but on the same machine (and OS), when perl has been built with -Duselongdouble, the output is -95.24436542871095.

Of course, the output of perl -V:archname would tell us for sure.

Cheers,
Rob