[9] RFR(L) 8166413: Integrate VM part of AOT changes

[Vladimir Kozlov]

Webrevs updated in place (please, reload webpage to get new version).

http://cr.openjdk.java.net/~kvn/aot/hs.webrev/

Included ppc64 and s390 changes. Corrected .hgignore in the hotspot.patch.

Thanks,
Vladimir

On 10/27/16 10:20 AM, Vladimir Kozlov wrote:
> Thank you, Volker
>
> I will integrate ppc and s390 changes after I merge jdk9/hs into AOT repo.
> And I will look on .hgignore.
>
> I use 'hg import --no-commit AOT.patch' command to apply patches.
>
> Thanks,
> Vladimir
>
> On 10/27/16 9:42 AM, Volker Simonis wrote:
>> Hi,
>>
>> first of all I had some problems importing the patch from the webrev
>> because of this sequence:
>>
>> --- old/./.hgignore       2016-10-26 14:56:22.000000000 -0700
>> +++ new/./.hgignore       2016-10-26 14:56:22.000000000 -0700
>> @@ -24,3 +24,19 @@
>>   ^test/compiler/jvmci/\w[\w\.]*/.*\.iml
>>   ^test/compiler/jvmci/\w[\w\.]*/nbproject
>>
>> The error (when using hg qpush -v) was:
>>
>> applying 8166413_AOT.patch
>> path './.hgignore' is inside nested repo '.'
>> committing changelog
>> patch failed, rejects left in working directory
>> errors during apply, please fix and qrefresh 8166413_AOT.patch
>>
>> I don't know how it was generated, but I could easily fix it by
>> replacing the above sequence by:
>>
>> --- old/.hgignore       2016-10-26 14:56:22.000000000 -0700
>> +++ new/.hgignore       2016-10-26 14:56:22.000000000 -0700
>>
>>
>> Besides that, it would be great if you could integrate the followinf
>> ppc/s390 specific changes which are required to keep the corresponding
>>   ports building:
>>
>> http://cr.openjdk.java.net/~simonis/webrevs/2016/8166413_ppc_s390_addon/
>>
>> Thanks,
>> Volker
>>
>>
>> On Thu, Oct 27, 2016 at 3:15 AM, Vladimir Kozlov
>> <vladimir.kozlov at oracle.com> wrote:
>>> AOT JEP:
>>> https://bugs.openjdk.java.net/browse/JDK-8166089
>>> Subtask:
>>> https://bugs.openjdk.java.net/browse/JDK-8166415
>>> Webrev:
>>> http://cr.openjdk.java.net/~kvn/aot/hs.webrev/
>>>
>>> Please, review Hotspot VM part of AOT changes.
>>>
>>> Only Linux/x64 platform is supported. 'jaotc' and AOT part of Hotspot will
>>> be build only on Linux/x64.
>>>
>>> AOT code is NOT linked during AOT libraries load as it happens with normal
>>> .so libraries. AOT code entry points are not exposed (not global) in AOT
>>> libraries. Only class data has global labels which we look for with
>>> dlsym(klass_name).
>>>
>>> AOT-compiled code in AOT libraries is treated by JVM as *extension* of
>>> existing CodeCache. When a java class is loaded JVM looks if corresponding
>>> AOT-compiled methods exist in loaded AOT libraries and add links to them
>>> from java methods descriptors (we have new field Method::_aot_code).
>>> AOT-compiled code follows the same invocation/deoptimization/unloading rules
>>> as normal JIT-compiled code.
>>>
>>> Calls in AOT code use the same methods resolution runtime code as calls in
>>> JITed code. The difference is call's destination address is loaded
>>> indirectly because we can't patch AOT code - it is immutable (to share
>>> between multiple JVM instances).
>>>
>>> Classes and Strings referenced in AOT code are resolved lazily by calling
>>> into runtime. All mutable pointers (oops (mostly strings), metadata) are
>>> stored and modified in a separate mutable memory (GOT cells) - they are not
>>> embedded into AOT code.
>>>
>>> Changes includes klass fingerprint generation since we need it to find
>>> correct klass data in loaded AOT libraries.
>>>
>>> Thanks,
>>> Vladimir