On Wed, 24 Jul 2024 10:07:48 GMT, Raffaello Giulietti <rgiulie...@openjdk.org> wrote:
> As I see it, there are some advantages in making the PR code as similar as > possible to the code in the paper: > > * It might result in simpler code (and maybe even faster code). > > * It would make the Java code easier to compare to the C code in the > paper. This would cause less head scratches to reviewers and contributors > that might want to evolve the code. > > * Since we know that (a variant) of that C code is in production since > many years in GMP, and since that code has been formally verified, there's > more confidence about its correctness. > > > Now, the C code has some obscure logic for the division by 2 S'. There's no > stringent need to emulate that part, I think. Also, the logic for the 1 bit > return value of the C function might be too cumbersome to emulate in the Java > code. > > Anyway, I think it would be beneficial to avoid the denormalization step in > the recursive `sqrtRemZimmermann()` method. If possible, normalization and > denormalization should only happen once in `sqrtRem()`. Initially, when I implemented the algorithm, I almost completely ignored the C code in the paper, because it seemed very obscure to me, and I relied solely on the logic of the pseudocode, even at the cost of writing a less efficient program. ------------- PR Comment: https://git.openjdk.org/jdk/pull/19710#issuecomment-2247559325
