RFR: 8358329: AArch64: emit direct branches in static stubs for small code caches [v2]

[Mikhail Ablakatov]

On Thu, 12 Jun 2025 07:44:24 GMT, Andrew Haley <aph at openjdk.org> wrote:

>> Mikhail Ablakatov has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   address review comments: use pd_patch_instruction directly
>>   
>>   MacroAssembler::pd_patch_instruction can distinguish between the `b`
>>   and `movk movz movz br` sequences. Strictly speaking, the method
>>   patches not a single instruction but a semantically joint sequence of
>>   instructions. Use it directly instead of `NativeJump` and
>>   `NativeGeneralJump` wrapper classes to simplify the implementation and
>>   get rid of an extra icache invalidation.
>>   
>>   Other changes in the patch simply clean up code that became redundant.
>
> Looks good. Please fix the copyright date.

The error in java/lang/Thread/virtual/stress/GetStackTraceALotWhenBlocking.java#id0 looks similar to what has been previously reported here: https://bugs.openjdk.org/browse/JDK-8344577 . @theRealAph , do you think the patch may cause the error? Or should I open a similar JBS ticket to report it?

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PR Comment: https://git.openjdk.org/jdk/pull/25702#issuecomment-2965724337