I was briefly very excited when I read that article, actually. But as devit points out in a sibling comment, that technique is only relevant to cases where you're adding more than 2 numbers.
Multiplication initially seemed like a very promising use case, since it's basically repeated addition. But I'm not super optimistic about that, because I think it's dominated by the alternate optimization of noticing that the product of two 64 bit numbers cannot saturate the high 64 bits of the resulting 128 bit number, which causes carries to be bounded [1].
Multiplication initially seemed like a very promising use case, since it's basically repeated addition. But I'm not super optimistic about that, because I think it's dominated by the alternate optimization of noticing that the product of two 64 bit numbers cannot saturate the high 64 bits of the resulting 128 bit number, which causes carries to be bounded [1].
[1] https://github.com/rocurley/bignum/blob/b45448a156fb9100ab06...