RFR: 8316180: Thread-local backoff for secondary_super_cache updates [v4]

[Aleksey Shipilev]

On Sat, 23 Sep 2023 08:37:46 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Aleksey Shipilev has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Cleaner AArch64 code
>
> src/hotspot/cpu/aarch64/macroAssembler_aarch64.cpp line 1542:
> 
>> 1540:     ldrw(rscratch1, Address(rthread, JavaThread::backoff_secondary_super_miss_offset()));
>> 1541:     subsw(rscratch1, rscratch1, 1);
>> 1542:     br(Assembler::GT, L_skip);
> 
> Suggestion:
> 
>     subw(rscratch1, rscratch1, 1);
>     cbzw(rscratch1, 31, L_skip);
> 
> 
> I know this is >= 0 rather than > 0, but that doesn't matter, and we should make this code small.

Did you mean `tbz(rscratch1, 31, L_skip);` here?

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PR Review Comment: https://git.openjdk.org/jdk/pull/15718#discussion_r1335426464