A few months ago there was a discussion [1] about changing Python's long integer type to use base 2**30 instead of base 2**15. http://bugs.python.org/issue4258 was opened for this. With much help from many people (but especially Antoine and Victor), I've finally managed to put together an essentially finished patch for this (see 30bit_longdigit14.patch in the tracker). I'd like to get this in for 3.1. Any objections or comments? Is this PEP territory? Summary of the patch: * Apart from improved performance, the effects should be almost entirely invisible to users. * By default, 30-bit digits are used only when both 32-bit and 64-bit integer types are available; otherwise the code falls back to the usual 15-bit digits. For Unix, there's a configure option --enable-big-digits that overrides this default. In particular, you can use --disable-big-digits to force 15-bit digit longs. * There's a new structseq sys.int_info that looks like this: >>> sys.int_info sys.int_info(bits_per_digit=30, sizeof_digit=4) the sizeof_digit is mostly there to help out the sys.getsizeof tests in test_sys. * Benchmarks show significant speedups (20% and more) for integer arithmetic on 64-bit systems, and lesser speedups on 32-bit systems. Operations with single-digit integers aren't affected much either way; most of the benefit seems to be for operations with small multi-digit integers. * There are more performance improvements planned (see the issue discussion for details); I left them out of the current patch for simplicity, and because they still need proper testing and benchmarking. Mark [1] http://mail.python.org/pipermail/python-dev/2008-November/083315.html