RFR: 8366478: BigDecimal roots [v9]

[Raffaello Giulietti]

On Fri, 24 Oct 2025 17:23:48 GMT, fabioromano1 <duke at openjdk.org> wrote:

>> For n > 0 the spec speaks about 0.5 ulp and 1 ulp, but not about correct rounding, which is slightly more restrictive, as it includes a direction (up, down, to-even, etc.).
>> If the implementation already returns the correctly rounded result when n > 0, then the spec could be more precise.
>
>> For n > 0 the spec speaks about 0.5 ulp and 1 ulp, but not about correct rounding, which is slightly more restrictive, as it includes a direction (up, down, to-even, etc.).
> 
> The statement "with rounding according to the context settings" together with the errors 0.5 ulp and 1 ulp seem to imply a correct rounding, am I wrong?

@fabioromano1 FYI, the renaming of `nthRoot`* to `rootn`* in `BigInteger` (and `MutableBigInteger`) has just been integrated.

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PR Comment: https://git.openjdk.org/jdk/pull/27148#issuecomment-3450049782