RFR: 8261447: MethodInvocationCounters frequently run into overflow [v8]

[Vladimir Kozlov]

On Tue, 2 Mar 2021 17:23:23 GMT, Lutz Schmidt <lucy at openjdk.org> wrote:

>> src/hotspot/cpu/x86/vtableStubs_x86_32.cpp line 159:
>> 
>>> 157:     return NULL;
>>> 158:   }
>>> 159: 
>> 
>> Why you did not update asm instruction to update `nof_megamorphic_calls` in this file?
>
> The reason is plain simple: there is no incrementq() for x86_32. I could emulate that with a few lines like
>     address ctrAddr = (address)SharedRuntime::nof_megamorphic_calls_addr();
>     __ lea(rscratch1, ExternalAddress(ctrAddr));
>     __ addl(Address(rscratch1, 0), 1);
>     __ adcl(Address(rscratch1, 4), 0);
> Not sure if that would be desirable here. Just let me know. As is, the code just updates the less significant half of the 8-byte counter.

Okay, let keep as it is. Then revert this file back - the only change is new empty line.

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PR: https://git.openjdk.java.net/jdk/pull/2511