[8u] RFR 8253353: Crash in C2: guarantee(n != NULL) failed: No Node

[Zhengyu Gu]

Rebased to monojdk8u:

http://cr.openjdk.java.net/~zgu/JDK-8253353-8u/webrev.01/

Thanks,

-Zhengyu

On 12/2/21 09:45, Zhengyu Gu wrote:
> I would like to backport this patch to openjdk8u for parity with Oracle 
> 8u331. The patch fixes a fatal crash initially reported for openjdk8u, 
> so it should be backported.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8253353
> 
> The backport is based on jdk11u backport, which is closer to 8u.
> Patch: https://hg.openjdk.java.net/jdk-updates/jdk11u/rev/04682d78ae28
> 
> The patch still does not apply cleanly.
> - 8u does not have PhaseIdealLoop::create_outer_strip_mined_loop() 
> method, stripped corresponding change in the method.
> - Slight context different in IdealLoopTree declaration.
> 
> 
> 8u webrev: http://cr.openjdk.java.net/~zgu/JDK-8253353-8u/webrev.00/
> 
> Test:
>    passed compiler/loopopts/TestNestedIrreducibleLoopsMain.java test
> 
> Thanks,
> 
> -Zhengyu