RFR: 8309271: A way to align already compiled methods with compiler directives [v15]

[Dmitry Chuyko]

On Wed, 20 Dec 2023 02:57:29 GMT, Andrei Pangin <apangin at openjdk.org> wrote:

>> Dmitry Chuyko has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 33 commits:
>> 
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - Merge branch 'openjdk:master' into compiler-directives-force-update
>>  - ... and 23 more: https://git.openjdk.org/jdk/compare/fde5b168...44d680cd
>
> src/hotspot/share/code/codeCache.cpp line 1409:
> 
>> 1407:   while(iter.next()) {
>> 1408:     CompiledMethod* nm = iter.method();
>> 1409:     methodHandle mh(thread, nm->method());
> 
> If there are two CompiledMethods for the same Java method, will it be scheduled for recompilation twice? Related question: if `nm` is an OSR method, does it make sense to go directly for deoptimization rather than compiling a non-OSR version?

If there are multiple method versions, it will be recompiled several times. The alternative is too keep some additional information which may complicate the code. OSRs is a good catch, I changed their handling to deopt.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14111#discussion_r1434887812