On Thu, 18 Jul 2024 15:28:23 GMT, Shaojin Wen <d...@openjdk.org> wrote:
>> class LocalTime {
>> public String toString() {
>> // ...
>> if (nanoValue % 1000_000 == 0) {
>> buf.append(Integer.toString((nanoValue / 1000_000) +
>> 1000).substring(1));
>> } else if (nanoValue % 1000 == 0) {
>> buf.append(Integer.toString((nanoValue / 1000) +
>> 1000_000).substring(1));
>> } else {
>> buf.append(Integer.toString((nanoValue) +
>> 1000_000_000).substring(1));
>> }
>> // ...
>> }
>> }
>>
>> Currently, LocalTime.toString handles nanos by adding a value and then
>> subString(1) to fill it with zeros. Using StringBuilder.repeat is more
>> concise and has better performance.
>
> Shaojin Wen has updated the pull request incrementally with one additional
> commit since the last revision:
>
> breaking on every 3 digits
Here are the performance numbers running on a MacBook M1 Max, 182.06%
performance improvement
-Benchmark Mode Cnt Score Error Units (master)
-ToStringBench.localTimeToString thrpt 15 7.752 ? 1.036 ops/ms
+Benchmark Mode Cnt Score Error Units (current
ac30276105e541dac48e0d11f4595f93202031b8)
+ToStringBench.localTimeToString thrpt 15 21.866 ? 0.417 ops/ms +182.06%
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PR Comment: https://git.openjdk.org/jdk/pull/20232#issuecomment-2236864823
