Fast bignum square computation

Question

To speed up my bignum divisons I need to speed up operation y = x^2 for bigints which are represented as dynamic arrays of unsigned DWORDs. To be clear:

Answer 1

If you're looking to write a new better exponent you might have to write it in assembly. This is the code from golang.

https://code.google.com/p/go/source/browse/src/pkg/math/exp_amd64.s

Answer 2

If I understand your algorithm correctly, it seems O(n^2) where n is the number of digits.

Have you looked at Karatsuba Algorithm? It speeds up multiplication using the divide and conquer approach. It may be worth taking a look at.