RFR: 8339531: Improve performance of MemorySegment::mismatch [v9]

[Brett Okken]

On Thu, 5 Sep 2024 17:47:16 GMT, Per Minborg <pminborg at openjdk.org> wrote:

>> This PR proposes to improve the performance of `MemorySegment::mismatch` by using Java code rather than transitioning to native code.
>
> Per Minborg has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix errors in a benchmark

src/java.base/share/classes/jdk/internal/foreign/SegmentBulkOperations.java line 244:

> 242:         return (Architecture.isLittleEndian()
> 243:                 ? Long.numberOfTrailingZeros(x)
> 244:                 : Long.numberOfLeadingZeros(x)) / 8;

Would there be value in having a constant LongToIntFunction lambda to capture this logic?


private static final LongToIntFunction LEADING_ZEROS = Architecture.isLittleEndian() ? Long::numberOfTrailingZeros : Long::numberOfLeadingZeros;

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PR Review Comment: https://git.openjdk.org/jdk/pull/20848#discussion_r1747281751