JDK-8347273 : C2: VerifyIterativeGVN for Ideal and Identity
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 25
  • Priority: P4
  • Status: Resolved
  • Resolution: Fixed
  • Submitted: 2025-01-08
  • Updated: 2025-07-01
  • Resolved: 2025-06-12
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JDK 26
26 b03Fixed
Related Reports
Blocks :  
JDK-8359103 - C2 VerifyIterativeGVN: Umbrella for extending Ideal and Identity verification (JDK-8347273)
Relates :  
JDK-8298952 - All nodes should have type(n) == Value(n) after IGVN
Relates :  
JDK-8357805 - C2: OpaqueDelayNode: arbitrarily delay IGVN optimizations
Relates :  
JDK-8361144 - Strenghten the Ideal Verification in PhaseIterGVN::verify_Ideal_for by comparing the hash of a node before and after Ideal
Relates :  
JDK-8359602 - Ideal optimizations depending on input type are missed because of missing notification mechanism from CCP
Relates :  
JDK-8359603 - VerifyIterativeGVN fails with "Missed optimization opportunity in PhaseIterGVN"
Description
Just like with JDK-8298952 for Value, we should verify that all Ideal and Identity optimizations were performed after IGVN. This is expensive, so we will only do it under the debug flag VerifyIterativeGVN.

We can also bail-out for a lot of node types, and more precisely analyze them in follow-up RFEs - they could be good starter tasks!
Comments
Changeset: dd688290 Branch: master Author: Emanuel Peter <epeter@openjdk.org> Date: 2025-06-12 14:19:08 +0000 URL: https://git.openjdk.org/jdk/commit/dd68829017c3adea4068d5311cab3fbef87b9577
12-06-2025
A pull request was submitted for review. Branch: master URL: https://git.openjdk.org/jdk/pull/22970 Date: 2025-01-08 14:43:40 +0000
09-06-2025
Draft: https://github.com/openjdk/jdk/pull/22970
08-01-2025