high speed arbitrary size integer math for perl

 Math::GMP was designed to be a drop-in replacement both for
 Math::BigInt and for regular integer arithmetic. Unlike BigInt,
 though, Math::GMP uses the GNU gmp library for all of its
 calculations, as opposed to straight Perl functions. This can result
 in speed improvements.
 .
 The downside is that this module is not 100% compatible to Math::BigInt.