RFR: 8077587: BigInteger Roots [v74]

[Joe Darcy]

On Thu, 28 Aug 2025 15:08:04 GMT, fabioromano1 <duke at openjdk.org> wrote:

>> This PR implements nth root computation for BigIntegers using Newton method.
>
> fabioromano1 has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 120 commits:
> 
>  - Merge branch 'openjdk:master' into nth-root-branch
>  - Ensure root's overestimate in for loop
>  - Refine comment
>  - Refine comment
>  - Refine comments
>  - Refine comments
>  - An optimization
>  - Code simplification
>  - Removed dead code
>  - Merge branch 'openjdk:master' into nth-root-branch
>  - ... and 110 more: https://git.openjdk.org/jdk/compare/993babb3...d5ff3a65

src/java.base/share/classes/java/math/BigInteger.java line 2747:

> 2745:     /**
> 2746:      * Returns the integer {@code n}th root of this BigInteger. The integer
> 2747:      * {@code n}th root {@code r} of the corresponding mathematical integer {@code x}

Formatting nit: in cases like this I would use `{@code n}<sup>th</sup>`.

src/java.base/share/classes/java/math/BigInteger.java line 2764:

> 2762:      * the magnitude of the real {@code n}th root if the latter is not representable
> 2763:      * as an integral value.
> 2764:      *

I think it would be helpful to the reader to have an `@apiNote` that explicitly said "nthRoot(2) is semantically equivalent to sqrt" even if that fact is implied by the other text.
The addition of such an `@apiNote` would not require additional CSR review.

-------------

PR Review Comment: https://git.openjdk.org/jdk/pull/24898#discussion_r2309142246
PR Review Comment: https://git.openjdk.org/jdk/pull/24898#discussion_r2309141035