mpmath is a library for arbitrary-precision floating-point arithmetic. It uses Python's native long type or gmpy2's mpz type for computations. It is available at https://pypi.python.org/pypi/mpmath.

The test suite can be run directly from the source tree. The test suite includes timing information for individual tests and for the the entire test. Sample invocation:

~/src/mpmath-0.19/mpmath/tests$ time py36 runtests.py -local

For example, I've tried to optimize gmpy2's handling of binary operations between its mpz type and short Python integers. I've found it to provide useful results: improvements that are significant on a micro-benchmark (say 20%) will usually cause a small but repeatable improvement. And some improvements that looked good on a micro-benchmark would slow down mpmath.

I ran the mpmath test suite with Python 3.6 and with the fastint6 patch. The overall increase when using Python long type was about 1%. When using gmpy2's mpz type, there was a slowdown of about 2%.

I will run more tests tonight.