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.
------------- Commit messages: - use Long.expand - Merge remote-tracking branch 'upstream/master' into optim_uuid_to_string_202501 - refactor - from j3graham - add comments - use ByteArrayLittleEndian - ues Long.expand - little endian - manual expand - Remove unnecessary steps - ... and 3 more: https://git.openjdk.org/jdk/compare/37f8e419...1059d39f Changes: https://git.openjdk.org/jdk/pull/22928/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22928&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8353741 Stats: 78 lines in 2 files changed: 47 ins; 27 del; 4 mod Patch: https://git.openjdk.org/jdk/pull/22928.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/22928/head:pull/22928 PR: https://git.openjdk.org/jdk/pull/22928
