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

[Bhateja, Jatin]

Hi Vladimir,

Thanks for taking care of this. 
Similar strict check for constant shift is needed in OrVNode::Ideal routine in vectornode.cpp.

Regards,
Jatin

> -----Original Message-----
> From: hotspot-compiler-dev <hotspot-compiler-dev-retn at openjdk.java.net> On
> Behalf Of Vladimir Kozlov
> Sent: Friday, September 4, 2020 3:14 AM
> To: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>
> Subject: [16] RFR(M) 8252188: Crash in OrINode::Ideal(PhaseGVN*,
> bool)+0x8b9
> 
> https://cr.openjdk.java.net/~kvn/8252188/webrev.00/
> 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