RFR: 8234906: [TESTBUG] TestDivZeroCheckControl fails for client VMs due to Unrecognized VM option LoopUnrollLimit

[christoph.goettschkes at microdoc.com]

Hi Vladimir,

Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote on 2019-11-27 20:54:02:

> From: Vladimir Kozlov <vladimir.kozlov at oracle.com>
> To: christoph.goettschkes at microdoc.com, 
hotspot-compiler-dev at openjdk.java.net
> Date: 2019-11-27 20:54
> Subject: Re: RFR: 8234906: [TESTBUG] TestDivZeroCheckControl fails for 
> client VMs due to Unrecognized VM option LoopUnrollLimit
> 
> Hi Christoph
> 
> I was about suggest IgnoreUnrecognizedVMOptions flag but remembered 
> discussion about 8231954 fix.

Yes, I try to avoid "IgnoreUnrecognizedVMOptions" because of our previous 
discussion. I also think that it doesn't make sense to execute tests in VM 
configurations for which they are not written for. Most of the compiler 
tests simply have "IgnoreUnrecognizedVMOptions" and probably waste a good 
amount of time in certain VM configurations.

> But I think the test should be run with Graal - it does have OSR 
> compilation and we need to test it.

Sure. I disabled it, because I thought that the flag "LoopUnrollLimit" is 
required to trigger the faulty behavior, but I don't know much about 
optimization in the graal JIT.

> 
> We can do it by splitting test runs (duplicate @test block with 
> different run flags) to have 2 tests with different 
> flags and conditions. See [1].
> 
> For existing @run block we use `@requires vm.compiler2.enabled` and for
> new without LoopUnrollLimit - `vm.graal.enabled`.

I did the following:

https://cr.openjdk.java.net/~cgo/8234906/webrev.01/

Could you elaborate how the two flags are related? I though, if graal is 
used as a JIT, both `vm.graal.enabled` and `vm.compiler2.enabled` are set 
to true. Is that correct? I don't have a setup with graal, so I can not 
test this.

Thanks,
Christoph