[11u] RFR (XS): 8239466: Loss of precision in counter decay calculation in 11u backport of JDK-8237375

[Langer, Christoph]

Hi,

I have backported JDK-8237375 [0] [1] to jdk11u (11.0.7) with the change [2].

Unfortunately, the backport contains a flaw that leads to a loss of precision when checking whether a counter decay is needed in method is_decay_needed() which in turn might yield the same test failures that we wanted to fix. Please review the correction:

http://cr.openjdk.java.net/~clanger/webrevs/8239466.11u/src/hotspot/share/runtime/compilationPolicy.cpp.frames.html

Thanks
Christoph

[0] https://bugs.openjdk.java.net/browse/JDK-8237375
[1] https://hg.openjdk.java.net/jdk/jdk/rev/2a0e2304e68b
[2] https://hg.openjdk.java.net/jdk-updates/jdk11u-dev/rev/695c552952bc