RFR: 8350329: C2: Div looses dependency on condition that guarantees divisor not zero in counted loop after peeling [v2]

[Roland Westrelin]

On Fri, 16 May 2025 09:28:51 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   review
>
> test/hotspot/jtreg/compiler/controldependency/TestPeeledLoopNoBackedgeFloatingDiv.java line 29:
> 
>> 27:  * @summary C2: Div looses dependency on condition that guarantees divisor not zero in counted loop after peeling
>> 28:  * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -XX:-UseLoopPredicate -XX:+StressGCM -XX:StressSeed=31780379 TestPeeledLoopNoBackedgeFloatingDiv
>> 29:  * @run main/othervm -XX:-TieredCompilation -XX:-BackgroundCompilation -XX:-UseLoopPredicate -XX:+StressGCM TestPeeledLoopNoBackedgeFloatingDiv
> 
> You should use `-XX:+UnlockDiagnosticVMOptions` for `StressGCM` and maybe also add `-XX:+IgnoreUnrecognizedVMOptions` when run without C2 since `UseLoopPredicate` is a C2 only flag.

Thanks for reviewing this. Done in the new commit.

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PR Review Comment: https://git.openjdk.org/jdk/pull/25262#discussion_r2092973861