RFR: 8370569: IGV: dump more graph properties at bytecode parsing [v3]

Roberto Castañeda Lozano rcastanedalo at openjdk.org
Tue Oct 28 12:38:07 UTC 2025


On Mon, 27 Oct 2025 15:54:35 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

>> This changeset makes it easier to trace C2's individual bytecode parsing steps to the input class files and the output of type flow analysis, by:
>> 
>> 1. dumping the `map` node (holding the JVM state), basic block (reverse post-order index), and method name as properties of the graph that C2 dumps after each parsed bytecode at IGV dump level 6;
>> 
>> 2. appending this information to the graph name (hence generalizing [JDK-8356779](https://bugs.openjdk.org/browse/JDK-8356779)); and
>> 
>> 3. making the graph name suffix configurable via `Options -> Graph Name Suffix`. By default, it appends `(map: [map], block #[block] at [method])` to the names of graphs containing these properties (bytecode parsing dumps), and nothing otherwise.
>> 
>> Here are the `Outline` and `Properties` windows for
>> 
>> $ java -Xbatch -XX:CompileOnly=java.lang.String::charAt -XX:PrintIdealGraphLevel=6
>> 
>> before (left) and after (right) the changeset:
>> 
>> <img width="2537" height="1032" alt="before-after" src="https://github.com/user-attachments/assets/cbd78f21-2501-4dcf-b757-86a556002d95" />
>> 
>> Please let me know if there are other bytecode parsing graph properties that could be useful to dump, and whether you think the default graph name suffix contains the right amount of information.
>> 
>> #### Testing
>>  - tier1.
>>  - Tested automatically that dumping thousands of graphs does not trigger any assertion failure on HotSpot or IGV.
>
> Roberto Castañeda Lozano has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove leftover from NetBeans code generation

Thanks for reviewing, Christian!

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PR Comment: https://git.openjdk.org/jdk/pull/27975#issuecomment-3456258436


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