RFR: 8356761: IGV: dump escape analysis information

Anton Seoane Ampudia aseoane at openjdk.org
Wed Nov 5 09:23:39 UTC 2025


This PR introduces new IGV dumps, property fields and filters related to escape analysis information.

The C2 escape analysis algorithm is carried out in six primary steps, of which many have interesting sub-steps (e.g. `split_unique_types`) or present an iterative nature where access to intermediate results can aid debugging and analysis. Additionally, escape analysis relies on an "intermediate structure" called the _connection graph_, which is also particularly valuable for deeper investigations.

With this changeset, escape analysis information is now dumped at key points throughout the algorithm, with a degree of granularity (from only the basic steps to in-detail iterative dumping). The dumps include several property fields, such as:

- Node escape “level”.
- Scalar replaceability.
- Node type within the connection graph (per [C2 Escape Analysis connection graph](https://wiki.openjdk.org/display/HotSpot/EscapeAnalysis)).

This is achieved by passing the `ConnectionGraph` in use to the `IdealGraphPrinter` during escape analysis, so that these properties can be dumped. After escape analysis, remaining interesting information that is left until macro elimination (and consequent elimination of non-escaping, replaceable allocations) is also dumped.

Additionally, two filters are provided: one for displaying the connection node type in the IGV node box, and another one for color-scaling nodes based on their escaping/scalar status.

**Testing:** passes tiers 1-3, manual testing in IGV

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

Commit messages:
 - Merge master
 - Remove unused include
 - Use print_method
 - Merge branch 'master' of github.com:openjdk/jdk into JDK-8356761
 - Merge
 - Add EA filters and better dumping experience
 - Fix ordering
 - More granularity
 - Reorder and rename
 - Sort includes
 - ... and 5 more: https://git.openjdk.org/jdk/compare/642ba4cf...872b1b48

Changes: https://git.openjdk.org/jdk/pull/28060/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28060&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8356761
  Stats: 170 lines in 8 files changed: 165 ins; 2 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/28060.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28060/head:pull/28060

PR: https://git.openjdk.org/jdk/pull/28060


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