RFR: 8305073: Fix VerifyLoopOptimizations - step 2 - verify idom [v3]

[Tobias Hartmann]

On Mon, 15 May 2023 09:38:52 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> This is the second step in the `VerifyLoopOptimizations` revival.
>> 
>> Last step:
>> [JDK-8173709](https://bugs.openjdk.org/browse/JDK-8173709) Fix VerifyLoopOptimizations - step 1 - minimal infrastructure 
>> See PR for all the planned steps: https://github.com/openjdk/jdk/pull/13207
>> 
>> Bug fixing for this step:
>> [JDK-8308084](https://bugs.openjdk.org/browse/JDK-8308084) C2 fix idom bug in PhaseIdealLoop::create_new_if_for_predicate
>> (https://github.com/openjdk/jdk/pull/13980)
>> 
>> Next step:
>> [JDK-8307982](https://bugs.openjdk.org/browse/JDK-8307982) Fix VerifyLoopOptimizations - step 3 - fix ctrl/loop
>> 
>> I added `TestVerifyLoopOptimizations.java` per @robcasloz 's request. It works just like `TestVerifyIterativeGVN.java`, with a simple `-Xcomp -XX:+VerifyLoopOptimizations` on a basically empty test. It fails until this patch is integrated: https://github.com/openjdk/jdk/pull/13980
>
> Emanuel Peter has updated the pull request incrementally with one additional commit since the last revision:
> 
>   add TestVerifyLoopOptimizations.java

Looks good to me.

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Marked as reviewed by thartmann (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/13951#pullrequestreview-1430262267