[9] RFR(S): 8071312: compiler/arguments/CheckCompileThresholdScaling.java fails

[Zoltán Majó]

Hi,


please review the following small patch.

Bug (nightly failure): https://bugs.openjdk.java.net/browse/JDK-8071312

Problem: The test compiler/arguments/CheckCompileThresholdScaling.java 
fails due to changes by 8059606. The reason of the failure is the 
changed logic for the case when CompileThresholdScaling==0.0.


Solution:

This patch changes the way the VM handles CompileThresholdScaling==0.0.

By convention, CompileThresholdScaling==0.0 is equivalent to -Xint.

Before, CompileThresholdScaling==0 set the value of all compilation 
thresholds to 0 *silently*. This behavior is inconsistent with the logic 
of -Xint, which leaves the values of the compilation thresholds unaffected.

With this change, if CompileThresholdScaling==0, the -Xint flag is set 
but the value of compilation thresholds is left unchanged.

I changed compiler/arguments/CheckCompileThresholdScaling.java test to 
reflect this behavior. Added test case for CompileThresholdScaling == 0 
with tiered compilation disabled.


Webrev: http://cr.openjdk.java.net/~zmajo/8071312/webrev.00/

Testing: manual testing, JPRT (all standard JPRT tests + 
CheckCompileThresholdScaling)

Thank you and best regards,


Zoltan