[11] RFR(S): 8199777: Deprecate -XX:+AggressiveOpts

[Vladimir Kozlov]

Hi Tobias,

EliminateAutoBox is C2 specific flag. Please, add -XX:+IgnoreUnrecognizedVMOptions flag in case 
someone has VM without C2.

Thanks,
Vladimir

On 3/20/18 2:20 AM, Tobias Hartmann wrote:
> Hi,
> 
> please review the following patch:
> https://bugs.openjdk.java.net/browse/JDK-8199777
> http://cr.openjdk.java.net/~thartmann/8199777/webrev.00/
> 
> The VM option "-XX:+AggressiveOpts" should be deprecated in JDK 11 and removed in a future release.
> The option was originally supposed to enable some experimental optimizations of the C2 compiler to
> improve performance of specific benchmarks. Most features have been removed or integrated over time
> leaving the behavior of the option ill-defined and error-prone. The only effect that the flag
> currently has is setting "AutoBoxCacheMax" to 20000 and "BiasedLockingStartupDelay" to 500. The same
> configuration can be achieved by setting the corresponding flags via the command line.
> 
> I've deprecated the flag and replaced the usages in tests by -XX:+EliminateAutoBox
> -XX:AutoBoxCacheMax=20000.
> 
> Thanks,
> Tobias
>