RFR(M) 8227003: [Graal] java/lang/invoke/VarHandles/VarHandleTestByteArrayAsInt.java time out

[Doug Simon]

Glancing through the web rev, I see new flags such as Tier40MinInvocationThreshold and Tier40CompileThreshold. Why “Tier40” instead of “Tier4"?

-Doug

> On 4 Oct 2019, at 08:30, Igor Veresov <igor.veresov at oracle.com> wrote:
> 
> The problem with this is that the test wants to run with -XX:-TieredCompilation in order to deterministically test the top level compiler. When we run this test with Graal we add -XX:+UseJVMCICompiler on top of that. The combination of these flags is extremely slow since Graal will have to compile itself while running in the interpreter, which causes timeouts. There are a lot of tests that behave this way.
> 
> The proposed solution is as follows. We introduce a special mode of tiered compilation that basically emulates the non-tiered mode - application code is profiled in the interpreter and then goes straight to the top level compiler. However, for the code of the JVMCI compiler we make an exception - it still gets to be compiled with C1 (level 1) as it normally does in tiered mode. The new mode integrates with AOT as well. As result the tests in question can execute an order of magnitude faster while still testing the top level compiler as these tests were designed to. 
> 
> I’d like to introduce a -XX:TieredMode=<number> flag to control this. See the webrev for its description. 
> 
> To make the tests work out-of-the-box I check if the flags -XX:-TieredCompilation and -XX:+UseJVMCICompiler are on the command line and turn the tiered compilation back on in non-tiered emulation mode. A warning is issued to alert the user to the change. This mode is also a step towards being able to remove the non-tiered policy.
> 
> Webrev: http://cr.openjdk.java.net/~iveresov/8227003/webrev.00/ <http://cr.openjdk.java.net/~iveresov/8227003/webrev.00/>
> JBS: https://bugs.openjdk.java.net/browse/JDK-8227003 <https://bugs.openjdk.java.net/browse/JDK-8227003>
> 
> igor
> 
> 
>