On Fri, 8 Apr 2022 12:16:17 GMT, Claes Redestad <[email protected]> wrote:
>> A few additional enhancements aiming to improve VH performance in the
>> interpreter:
>>
>> - Flatten `TypeAndInvokers`: adds a pointer to `VarHandle` (a small increase
>> 40->48) but removes an object and an indirection on any instance actually
>> used - and might avoid allocating the `MethodHandle[]` unnecessarily on some
>> instances
>> - Have `checkExactAccessMode` return the directness of the `VarHandle` so
>> that we can avoid some `isDirect` method calls.
>>
>> Baseline, `-Xint`
>>
>> Benchmark Mode Cnt Score Error Units
>> VarHandleExact.exact_exactInvocation avgt 30 478.324 ? 5.762 ns/op
>> VarHandleExact.generic_exactInvocation avgt 30 392.114 ? 1.644 ns/op
>> VarHandleExact.generic_genericInvocation avgt 30 822.484 ? 1.865 ns/op
>>
>>
>> Patched, `-Xint`
>>
>> Benchmark Mode Cnt Score Error Units
>> VarHandleExact.exact_exactInvocation avgt 30 437.704 ? 5.320 ns/op
>> VarHandleExact.generic_exactInvocation avgt 30 374.512 ? 3.154 ns/op
>> VarHandleExact.generic_genericInvocation avgt 30 757.054 ? 1.237 ns/op
>>
>>
>> No significant performance difference in normal mode.
>
> Claes Redestad has updated the pull request incrementally with one additional
> commit since the last revision:
>
> Simplified as suggested by @ExE-Boss
src/java.base/share/classes/java/lang/invoke/IndirectVarHandle.java line 104:
> 102: if (exact && accessModeType(ad.type) !=
> ad.symbolicMethodTypeExact) {
> 103: throwWrongMethodTypeException(ad);
> 104: }
This could also be:
Suggestion:
super.checkExactAccessMode(ad);
-------------
PR: https://git.openjdk.java.net/jdk/pull/8160
