RFR: 8314233: C2: assert(assertion_predicate_has_loop_opaque_node(iff)) failed: unexpected

[Tobias Hartmann]

On Tue, 15 Aug 2023 13:42:48 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

> In the testcase, we try to initialize Assertion Predicates from the templates which have an `Opaque4` node. However, the code finds an unrelated `Opaque4` node added by an intrinsic. This, obviously, will not guard any `OpaqueLoop*` nodes required for Template Assertion Predicates and we fail with the assertion.
> 
> While splitting some changes away from the main fix of [JDK-8288981](https://bugs.openjdk.org/browse/JDK-8288981) for [JDK-8305636](https://bugs.openjdk.org/browse/JDK-8305636), I wrongly removed the check in loop peeling if an `Opaque4` node belongs to an `If` that also shares the uncommon trap with the Parse Predicate (this is not required in the main fix anymore because Template Assertion Predicates will always only have `HaltNodes` - but optimizing this here is wrong/too early).
> 
> The fix re-establishes the check for the uncommon trap.
> 
> Thanks,
> Christian

Looks good to me.

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Marked as reviewed by thartmann (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/15290#pullrequestreview-1578603607