On Mon, 19 May 2025 23:53:07 GMT, Shaojin Wen <s...@openjdk.org> 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 469: > 467: buf[18] = '-'; > 468: buf[23] = '-'; > 469: I would suggest a comment here along the lines of "Although the UUID byte ordering is defined to be big-endian, LittleEndian is used here to optimize for the most common architectures. `hex8` reverses the order internally." ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/22928#discussion_r2099081840