The gmp package contains GNU MP, a library for arbitrary precision
arithmetic, signed integers operations, rational numbers and floating
point numbers. GNU MP is designed for speed, for both small and very
large operands.

GNU MP is fast for several reasons:
- it uses fullwords as the basic arithmetic type,
- it uses fast algorithms
- it carefully optimizes assembly code for many CPUs' most common
inner loops
- it generally emphasizes speed over simplicity/elegance in its
operations