RFR: 8198571: [JVMCI] must not install wide vector code unless runtime supports it

[Doug Simon]

Yes. We have a separate fix for Graal that does what you propose. This is just a last bit of defense to prevent a VM crash in case the bug creeps back into Graal (or any other JVMCI compiler).

Sent from my iPhone

> On 23 Feb 2018, at 8:54 pm, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
> 
> Hi Doug,
> 
> Are you planning changes to check MaxVectorSize value when vectors are generated by Graal?
> Throwing exception during code installation is very late and expensive (you have to throw out all methods with vectors after spending CPUs to compile them).
> 
> Thanks,
> Vladimir
> 
>> On 2/23/18 8:57 AM, Doug Simon wrote:
>> As shown in https://github.com/oracle/graal/issues/303, a bug in a JVMCI compiler can result in vector code being installed even if the runtime doesn't support it. JVMCI should be defensive and raise an exception in this case.
>> https://bugs.openjdk.java.net/browse/JDK-8198571
>> http://cr.openjdk.java.net/~dnsimon/8198571/
>> -Doug