RFR: 8341470: BigDecimal.stripTrailingZeros() optimization [v12]

[fabioromano1]

On Wed, 9 Oct 2024 16:17:59 GMT, Raffaello Giulietti <rgiulietti at openjdk.org> wrote:

>> @rgiulietti BTW of opening new issues, I've found that there are some optimizations and code simplifications that can be done in `BigInteger`'s bit operations that uses lowest non-zero word search, like `shiftRight()`, `getLowestSetBit()`, `bitLength()` and `bitCount()`.
>
> If you are interested, you can create new PRs without reference to JBS issues, and I'll file them.
> As usual, it's easier for review purposes when each PR touches only small groups of strongly related changes rather than big modifications en-bloc.
> 
> But you should show JMH benchmark evidence in later comments (not the introductory comment) that there are no performance regressions, in addition to code simplification.

@rgiulietti I think I just found a problem much more serious than a simple optimization, I'm afraid the semantics of `BigInteger.bitCount()` is ill-defined, although it seems absurd to me that no one has noticed it so far...

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

PR Review Comment: https://git.openjdk.org/jdk/pull/21323#discussion_r1793898050