JDK-8298951 : Umbrella: improve CCP and IGVN verification
  • Type: Enhancement
  • Component: hotspot
  • Sub-Component: compiler
  • Affected Version: 21
  • Priority: P4
  • Status: Open
  • Resolution: Unresolved
  • Submitted: 2022-12-16
  • Updated: 2024-10-28
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Other
tbdUnresolved
Related Reports
Relates :  
JDK-8273496 - Make sure that CCP adds nodes to the IGVN worklist
Relates :  
JDK-8293362 - Extend detection of modified nodes to incremental inlining
Relates :  
JDK-8298094 - Refactor PhaseCCP and IGVN notification
Relates :  
JDK-8257197 - Add additional verification code to PhaseCCP
Relates :  
JDK-8343067 - C2: revisit constant-offset AddP chains after successful input idealizations
Relates :  
JDK-8302071 - StressIGVN: not just initial shuffle_worklist: always pick next node at random
Relates :  
JDK-8298952 - All nodes should have type(n) == Value(n) after IGVN
Relates :  
JDK-8308149 - C2 VerifyIterativeGVN: verify CFG consistency (MultiBranchNode::required_outcnt() == outcnt())
Description
Verify that all optimizations that we can take are in fact taken.

This includes the following steps:
JDK-8257197 Verify that all nodes have "type(n) == Value(n)" after CCP
JDK-8298952 Verify that all nodes have "type(n) == Value(n)" after IGVN

See if we can do more verification for LoadNode::Value, maybe disable some optimizations during verification?

JDK-8302071 IGVN shuffle_worklist: we should try to do random selection instead!

Take more steps to do similar checks for Node::Ideal and Node::Identity.

JDK-8308149 Verify number of out-projection from MultiBranch

Verify consistency of Loop nodes (especially CountedLoop with tripcount phi etc)

JDK-8293362: Extend detection of modified nodes to incremental inlining

Investigate what to do about JDK-8273496

After all the verification is added, we should do this:
Refactor the CCP / IGVN notification code JDK-8298094