RFR: JDK-8310502 : Optimization for j.l.Long.fastUUID() [v29]

[Chen Liang]

On Tue, 27 Jun 2023 17:30:35 GMT, 温绍锦 <duke at openjdk.org> wrote:

>> By optimizing the implementation of java.lang.Long#fastUUID, the performance of the java.util.UUID#toString method can be significantly improved.
>> 
>> The following are the test results of JMH: 
>> 
>> Benchmark                     Mode  Cnt      Score      Error   Units
>> UUIDUtilsBenchmark.new       thrpt    5  92676.550 ±  292.213  ops/ms
>> UUIDUtilsBenchmark.original  thrpt    5  37040.165 ± 1023.532  ops/ms
>
> 温绍锦 has updated the pull request incrementally with one additional commit since the last revision:
> 
>   revert to HexDigits.DIGITS, keep this PR as simple as possible.

src/java.base/share/classes/java/util/HexDigits.java line 33:

> 31: 
> 32: import static jdk.internal.digits.Hex256.hex256;
> 33: 

Suggestion:


This is now redundant and causes build failure.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14578#discussion_r1244118063