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

[christoph.goettschkes at microdoc.com]

Hi Vladimir,

could you have a look at my updated webrev regarding this failing test?
https://cr.openjdk.java.net/~cgo/8234906/webrev.01/

See my inline comments in the mail below.

Thanks,
Christpoh

"hotspot-compiler-dev" <hotspot-compiler-dev-bounces at openjdk.java.net> 
wrote on 2019-11-28 13:44:05:

> From: christoph.goettschkes at microdoc.com
> To: Vladimir Kozlov <vladimir.kozlov at oracle.com>
> Cc: hotspot-compiler-dev at openjdk.java.net
> Date: 2019-11-28 13:46
> Subject: Re: RFR: 8234906: [TESTBUG] TestDivZeroCheckControl fails for 
> client VMs due to Unrecognized VM option LoopUnrollLimit
> Sent by: "hotspot-compiler-dev" 
<hotspot-compiler-dev-bounces at openjdk.java.net>
> 
> 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
>