Integrated: 8316361: C2: assert(!failure) failed: Missed optimization opportunity in PhaseIterGVN with -XX:VerifyIterativeGVN=10

[Emanuel Peter]

On Fri, 22 Sep 2023 10:47:00 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> This seems to be related to [JDK-8298176](https://bugs.openjdk.org/browse/JDK-8298176) / https://github.com/openjdk/jdk20/pull/65
> This change allows `OpaqueZeroTripGuard -> CmpI` to fold in some cases. We have also added code to notify the `CmpI` during IGVN, so it can potentially change its type/constant fold:
> https://github.com/openjdk/jdk/blob/a0a09d56ba4fc6133b423ad29d86fc99dd6dc19b/src/hotspot/share/opto/phaseX.cpp#L1681-L1687
> 
> However, when we hack the input to the `opaq` node, we must call `_igvn.add_users_to_worklist` to trigger this notification. I added this missing part.
> 
> Running Tier1-6 and stress testing... passed.

This pull request has now been integrated.

Changeset: eeb63cd0
Author:    Emanuel Peter <epeter at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/eeb63cd0fad9de1f7182ab97d0f25ac67745aa9e
Stats:     50 lines in 2 files changed: 50 ins; 0 del; 0 mod

8316361: C2: assert(!failure) failed: Missed optimization opportunity in PhaseIterGVN with -XX:VerifyIterativeGVN=10

Reviewed-by: kvn, chagedorn

-------------

PR: https://git.openjdk.org/jdk/pull/15886