Did you read the code for the underlying gmp c code? And associated c APIs? 

I'm told that part of the value of the new style gmp binding is that it should be safer to link to any missing gmp functionality you may wish to use. 

On Sunday, June 19, 2016, Henning Thielemann <lemming@henning-thielemann.de> wrote:

On Sun, 19 Jun 2016, David Feuer wrote:

Your quick look is insufficient. There are custom implementations of bit setting and clearing operations that use GMP primitives instead of the Data.Bits defaults.

I have seen them, but the expensive operations like 'union' and 'difference' are not optimized, right? They would benefit from CPU vector instructions.