RFR: 8316694: Implement relocation of nmethod within CodeCache [v18]

[Chad Rakoczy]

On Wed, 28 May 2025 13:31:48 GMT, Evgeny Astigeevich <eastigeevich at openjdk.org> wrote:

>> Chad Rakoczy has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Add JVMCINMethodData::has_mirror()
>
> src/hotspot/cpu/aarch64/relocInfo_aarch64.cpp line 90:
> 
>> 88:       }
>> 89:     }
>> 90:     call->set_destination(x);
> 
> The new code does not update trampoline with `x`. Also you need to handle properly the case of `trampoline` being null. IMO it should never be null. So `if` is not needed. I'd use `guarantee` here.

The trampoline should never been null when compiled with C1/C2. However when running on a debug build  `Assembler::reachable_from_branch_at` uses 2M (on aarch64) for the branch range where as Graal always uses the max of 128M regardless of release/debug. In that case it is possible for `trampoline` to be null.

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PR Review Comment: https://git.openjdk.org/jdk/pull/23573#discussion_r2112341501