RFR: 8356891: Some code simplifications in BigInteger [v22]

[Raffaello Giulietti]

On Wed, 21 May 2025 09:12:49 GMT, fabioromano1 <duke at openjdk.org> wrote:

>> Some changes in `Biginteger`s' bit operations that increase the code readability and slightly optimize the execution time.
>
> fabioromano1 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Correct typo in comment

src/java.base/share/classes/java/math/BigInteger.java line 4547:

> 4545:      * If the source is trusted the copying may be skipped.
> 4546:      */
> 4547:     private static int[] stripLeadingZeroInts(int[] val, boolean trusted) {

I suggest to restore `trustedStripLeadingZeroInts()`, with an implementation that just invokes this one with `trusted` set to `true`.
And then restore the `trustedStripLeadingZeroInts()` invocations. The name is more intent-revealing and somewhat more conventional.

src/java.base/share/classes/java/math/BigInteger.java line 4732:

> 4730:         /* Allocate output array.  If all non-sign ints are 0x00, we must
> 4731:          * allocate space for one extra output int. */
> 4732:         for (i = a.length - 1; i >= keep && a[i] == 0; i--) // Skip trailing zeros

I think there's no need to check for `i >= keep`.
Suggestion:

        for (i = a.length - 1; a[i] == 0; i--) // Skip trailing zeros

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PR Review Comment: https://git.openjdk.org/jdk/pull/25166#discussion_r2109478579
PR Review Comment: https://git.openjdk.org/jdk/pull/25166#discussion_r2109510018