RFR(S): 8159620: -XX:-UseOnStackReplacement does not work together with -XX:+TieredCompilation on ppc64 and sparc

[Lindenmaier, Goetz]

Hi Volker, 

thanks for doing this fix, I also have run into this issue before ...
Looks good.

Small nit: usually
  }
  else {
are on one line.

Best regards,
  Goetz.

> -----Original Message-----
> From: hotspot-dev [mailto:hotspot-dev-bounces at openjdk.java.net] On
> Behalf Of Volker Simonis
> Sent: Donnerstag, 16. Juni 2016 16:54
> To: HotSpot Open Source Developers <hotspot-dev at openjdk.java.net>
> Subject: RFR(S): 8159620: -XX:-UseOnStackReplacement does not work
> together with -XX:+TieredCompilation on ppc64 and sparc
> 
> Hi,
> 
> can I please have a review and sponsor for the following small change
> which fixes -XX:-UseOnStackReplacement to work together with
> -XX:+TieredCompilation:
> 
> http://cr.openjdk.java.net/~simonis/webrevs/2016/8159620/
> https://bugs.openjdk.java.net/browse/JDK-8159620
> 
> This is a long standing bug on SPARC and as the ppc64 template
> interpreter was initially forked from the SPARC implementation, it
> also manifests there. The problem is that in the case of tiered
> compilation the interpreter unconditionally calls
> InterpreterRuntime::frequency_counter_overflow if the back edge
> counter overflows. This triggers an OSR compilation, even if OSR was
> switched off with -XX:-UseOnStackReplacement.
> 
> The fix is simple - just don't call
> InterpreterRuntime::frequency_counter_overflow if OSR has been
> switched off.
> 
> Thank you and best regards,
> Volker