RFR: Enable array access instrumentation for aarch64

[Jie He]

On Wed, 17 Jun 2020 07:04:11 GMT, Man Cao <manc at openjdk.org> wrote:

> > Did you test the previous C1 with tsan enabled?
> 
> No. It was work-in-progress in 2017, and the author left our team and no one has picked it up afterwards. I vaguely
> recall there were some issues with deoptimization, but I don't know about the details.
> > could it benefit race detection for real workload than interpreter version? as we know, interpreter will report the
> > race before C1 involved.
> 
> I don't quite get the question. tsan-in-C1 should only improve the speed of program execution, but does not affect the
> coverage of race detection. Races detectable with C1 instrumentation are also detectable with interpreter-only
> instrumentation. Currently TSAN should only be used in interpreter-only mode. -XX:+ThreadSanitizer implies -Xint, see
> here:
> https://github.com/openjdk/tsan/blob/5b22e1802c285b7a3b8764ac90da36476d08311a/src/hotspot/share/runtime/arguments.cpp#L4046

yes, I knew tsan disabled compiler mode, I just wonder if the speed improvement by enabling tsan in c1 is worth the
complexity.

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PR: https://git.openjdk.java.net/tsan/pull/13