On Mon, 19 May 2025 23:53:07 GMT, Shaojin Wen <[email protected]> wrote:
>> Improve the performance of UUID::toString by using Long.expand and SWAR
>> (SIMD within a register) instead of table lookup. Eliminating the table
>> lookup can also avoid the performance degradation problem when the cache
>> misses.
>
> Shaojin Wen has updated the pull request incrementally with one additional
> commit since the last revision:
>
> hex8 comments
src/java.base/share/classes/java/util/UUID.java line 534:
> 532: */
> 533: private static long hex8(long i) {
> 534: // Expand each 4-bit group into 8 bits, spreading them out in
> the long value: 0xAABBCCDD -> 0x0A0B0C0D0A0B0C0D
should be `0xAABBCCDD -> 0xA0A0B0B0C0C0D0D`
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PR Review Comment: https://git.openjdk.org/jdk/pull/22928#discussion_r2099076402
