RFR: 8316197: Make tracing of inline cache available in unified logging [v3]

[David Holmes]

On Fri, 8 Dec 2023 18:50:38 GMT, Yi-Fan Tsai <duke at openjdk.org> wrote:

>> This removes develop flag `TraceICs` and makes the logs available via `-Xlog`.
>> 
>> Example:
>> 
>> % java -Xlog:inlinecache=trace -version
>> [0.061s][trace][inlinecache] CompiledDirectStaticCall at 0x00007f3739001d17: set_to_interpreted java.lang.StringLatin1.hashCode([B)I
>> [0.078s][trace][inlinecache] IC at 0x00007f3739004a87: monomorphic to compiled (rcvr klass = nullptr)
>> [0.079s][trace][inlinecache] CompiledDirectStaticCall at 0x00007f3739005dff: set_to_interpreted jdk.internal.util.ArraysSupport.vectorizedHashCode(Ljava/lang/Object;IIII)I
>> [0.079s][trace][inlinecache] CompiledDirectStaticCall at 0x00007f373900502f: set_to_interpreted jdk.internal.org.objectweb.asm.ByteVector.enlarge(I)V
>> [0.079s][trace][inlinecache] IC at 0x00007f373900502f: monomorphic to interpreter: {method} {0x00007f36f03e6318} 'enlarge' '(I)V' in 'jdk/internal/org/objectweb/asm/ByteVector'
>> [0.079s][trace][inlinecache] CompiledDirectStaticCall at 0x00007f3739006b0f: set_to_compiled 0x00007f3739002120
>> [0.083s][trace][inlinecache] CompiledDirectStaticCall at 0x00007f373900928f: set_to_interpreted java.lang.AbstractStringBuilder.newCapacity(I)I
>> [0.083s][trace][inlinecache] IC at 0x00007f373900928f: monomorphic to interpreter: {method} {0x00007f36f00cd170} 'newCapacity' '(I)I' in 'java/lang/AbstractStringBuilder'
>> ...
>
> Yi-Fan Tsai has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Enable inlinecache logs in TestTraceICs

Code changes look fine to me.

I think the test can go but that is up to @vnkozlov .

Thanks

test/hotspot/jtreg/compiler/arguments/TestTraceICs.java line 27:

> 25:  * @test
> 26:  * @bug 8217447
> 27:  * @summary Test running TraceICs enabled.

The summary is no longer applicable.

But really this test seems some what pointless. It basically checks that `Xlog:inlinecache` is a valid log setting, but doesn't actually check anything interesting.

-------------

Marked as reviewed by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/17026#pullrequestreview-1774275135
PR Review Comment: https://git.openjdk.org/jdk/pull/17026#discussion_r1421938428