Bigint (bigbit) library.

Question

I'm looking for a c++ class/library that provides 1024 bit and bigger integers and bit operations like: - bit shifting, - bitwise OR/AND, - position first zero bit

speed is crucial, so it would have to be implemented with some SIMD assembly.

Answer 1

try gmp library. It is a C library. Beginning with GMP 4.0 a C++ wrapper is bundled with the release.

Answer 2

There are several, including GMP, but for speed, the best is likely TTmath. TTmath's design decision to use templated fixed lengths at compiletime lets it be quite fast.