RFR: 8253525: Implement getInstanceSize/sizeOf intrinsics [v3]

[Vladimir Kozlov]

On Mon, 19 Oct 2020 06:57:24 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

>> This is fork off the SizeOf JEP, JDK-8249196. There is already the entry point in JDK that can use the intrinsic like
>> this: `Instrumentation.getInstanceSize`. Therefore, we can implement the C1/C2 intrinsic now, hook it up to
>> `Instrumentation`, and let the tools use that fast path today.  With this patch, JOL is able to be close to
>> `deepSizeOf` implementation from SizeOf JEP.
>> Example performance improvements for sizing up a custom linked list:
>> 
>> Benchmark                     (size)  Mode  Cnt       Score      Error  Units
>> 
>> # Default
>> LinkedChainBench.linkedChain       1  avgt    5     705.835 ±    8.051  ns/op
>> LinkedChainBench.linkedChain      10  avgt    5    3148.874 ±   37.856  ns/op
>> LinkedChainBench.linkedChain     100  avgt    5   28693.256 ±  142.254  ns/op
>> LinkedChainBench.linkedChain    1000  avgt    5  290161.590 ± 4594.631  ns/op
>> 
>> # Instrumentation attached, no intrinsics
>> LinkedChainBench.linkedChain       1  avgt    5    159.659 ±   19.238  ns/op
>> LinkedChainBench.linkedChain      10  avgt    5    717.659 ±   22.540  ns/op
>> LinkedChainBench.linkedChain     100  avgt    5   7739.394 ±  111.683  ns/op
>> LinkedChainBench.linkedChain    1000  avgt    5  80724.238 ± 2887.794  ns/op
>> 
>> # Instrumentation attached, new intrinsics
>> LinkedChainBench.linkedChain       1  avgt    5     95.254 ±   0.808  ns/op
>> LinkedChainBench.linkedChain      10  avgt    5    261.564 ±   8.524  ns/op
>> LinkedChainBench.linkedChain     100  avgt    5   3367.192 ±  21.128  ns/op
>> LinkedChainBench.linkedChain    1000  avgt    5  34148.851 ± 373.080  ns/op
>
> Aleksey Shipilev has refreshed the contents of this pull request, and previous commits have been removed. The
> incremental views will show differences compared to the previous content of the PR.

test/jdk/java/lang/instrument/GetObjectSizeTest.java line 2:

> 1: /*
> 2:  * Copyright (c) 2020, Red Hat, Inc. All rights reserved.

You can't replace Copyright lines of one company with other.

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PR: https://git.openjdk.java.net/jdk/pull/650