RFR: 8261847: performace of java.lang.Record::toString should be improved [v4]

[Jim Laskey]

On Mon, 22 Nov 2021 15:56:46 GMT, Claes Redestad <redestad at openjdk.org> wrote:

>> Vicente Romero has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   setting max split size to 20
>
> src/java.base/share/classes/java/lang/runtime/ObjectMethods.java line 314:
> 
>> 312:                     ).getTarget();
>> 313:                     mhs[splitIndex] = MethodHandles.filterArguments(mhs[splitIndex], 0, currentSplitGetters);
>> 314:                     mhs[splitIndex] = MethodHandles.permuteArguments(
> 
> This is some gnarly logic. Could we add some comments on what permuteArguments with a reorder array of just zeros is doing here?

This is not unusual. It spreads a single argument across several "getters". But a comment wouldn't hurt.

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PR: https://git.openjdk.java.net/jdk/pull/6403