(original) (raw)

I think I had made a similar request a couple of years ago or so on this list. Personally, I'd find output to tty useful, akin to PrintInlining. LogCompilation is useful for tools, but basic diagnostic output for human consumption would be great.

Also, now that superword is seeing some love, it'd be nice to have diagnostic output for vectorization (i.e. loop xyz vectorized, not vectorized due to ..., etc).

Thanks

sent from my phone

On Jun 19, 2015 7:03 AM, "Vladimir Ivanov" <vladimir.x.ivanov@oracle.com> wrote:

Chris,

I'd suggest to look into enhancing LogCompilation output instead of parsing VM output. It doesn't require any flag changes and fits nicely into existing LogCompilation functionality, so we can integrate it into the product, relieving you and JITWatch users from building a companion VM.

Best regards,
Vladimir Ivanov

On 6/19/15 1:16 PM, Chris Newland wrote:

Hi, hope this is the correct list (perhaps serviceability?)

I'm experimenting with some HotSpot changes that log escape analysis
decisions so that I can visualise eliminated allocations at the source and
bytecode levels in JITWatch\[1\].

My plan was to build a companion VM for JITWatch based on the product VM
that would allow users to inspect some of the deeper workings such as EA
and DCE that are not present in the LogCompilation output.

I mentioned this to some performance guys at Devoxx and they didn't like
the custom VM idea and suggested I put in a request to consider making
\-XX:+PrintEscapeAnalysis available under -XX:+UnlockDiagnosticVMOptions on
the product VM (it's currently a notproduct option).

If this is something you would consider than could I also request
consideration of -XX:+PrintEliminateAllocations.

All I would need is the class, method, and bci of each NoEscape detected.

Kind regards,

Chris

\[1\] https://github.com/AdoptOpenJDK/jitwatch