[16] RFR(M) 8252188: Crash in OrINode::Ideal(PhaseGVN*, bool)+0x8b9

[Vladimir Ivanov]

> https://cr.openjdk.java.net/~kvn/8252188/webrev.00/

Looks good.

Best regards,
Vladimir Ivanov

> https://bugs.openjdk.java.net/browse/JDK-8252188
> 
> Code added by 8248830 [1] uses Node::is_Con() check when looking for 
> constant shift values.
> Unfortunately it does not guarantee that it will be Integer constant 
> because TOP node is also ConNode.
> I used C2 types to check and get shift values. I also refactor code to 
> consolidate checks.
> 
> Tested: tier1, hs-tier2, hs-tier3.
> Verified fix with replay file from bug report.
> I also checked that RotateBenchmark.java added by 8248830 still creates 
> Rotate vectors after this fix.
> 
> I created subtask to add new regerssion test later because this fix is 
> urgent and I did not have time to prepare it.
> 
> Thanks,
> Vladimir
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8248830