* Bit by bit method using integer arithmetic. (Slow, but portable)
* 1. Normalization
* Scale x to y in [1,4) with even powers of 2:
- * find an integer k such that 1 <= (y=x*2^(2k)) < 4, then
+ * find an integer k such that 1 <= (y=x*2^(-2k)) < 4, then
* sqrt(x) = 2^k * sqrt(y)
* 2. Bit by bit computation
* Let q = sqrt(y) truncated to i bit after binary point (q = 1),