RFR: 8353741: Improve UUID.toString performance by using SIMD within a register instead of table lookup [v3]

Shaojin Wen swen at openjdk.org
Sat Apr 5 05:30:25 UTC 2025


> 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:

  simplify code

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/22928/files
  - new: https://git.openjdk.org/jdk/pull/22928/files/93d283e4..55223571

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22928&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22928&range=01-02

  Stats: 13 lines in 1 file changed: 0 ins; 4 del; 9 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


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