Int128 in .Net?

Question

I need to do some large integer math. Are there any classes or structs out there that represent a 128-bit integer and implement all of the usual operators?

BTW, I r

Answer 1

BigInteger is now a standard part of C# and friends in .NET 4.0. See:Gunnar Peipman's ASP.NET blog. Note that the CPU can generally work with ordinary integers much more quickly and in constant time, especially when using the usual math operators (+, -, /, ...) because these operators typically map directly to single CPU instructions.

With BigInteger, even the most basic math operations are much slower function calls to methods whose runtime varies with the size of the number. This is because BigInteger implements arbitrary precision arithmetic, which adds considerable but necessary overhead. The benefit is that BigIntegers are not limited to 64 or even 128 bits, but by available system memory (or about 2^64 bits of precision, whichever comes first). Read here.