I have once again uploaded a new version of my big integer library (available at http://groups.yahoo.com/group/boost/files/big_integer/, version 0.3). The divison algorithm is completely new, and this time it is fast (it now uses Knuth's algorithm). The code is also reorganised, which made it quite easy to build in support for GNU MP and CLN. When either of those two libraries is available, set BOOST_BIG_INTEGER_USE_GMP or BOOST_BIG_INTEGER_USE_CLN, and those libraries will be used to implement the basic arithmetic functions. Those libraries aren't completely supported yet, a few functions (mostly conversion functions from types larger than int) need to be implemented correctly (it's kindof hacked together right now), and most noticeable, cln hasn't got power_mod yet, because I was unable to find the matching function in the cln library. That aside, it shows that it is quite easy to make the library work with other libraries to provide speedy implementations with a uniform interface. Best regards, Richard Peters ----- Original Message ----- From: "Joel Young" <jdy@cs.brown.edu>
I made a simple program with some big numbers that demonstrate the speed difference:
The summary is that big_integer is making millions of iterator calls and lexicographical_compares, while even boost::rational using long long is just making a few calls to things like boost::gcd.
Joel