RFR: 8350208: CTW: GraphKit::add_safepoint_edges asserts "not enough operands for reexecution"

[Quan Anh Mai]

On Thu, 11 Dec 2025 02:09:08 GMT, Dean Long <dlong at openjdk.org> wrote:

>> Hi,
>> 
>> This PR fixes the issue of the compiler crashing with "not enough operands for reexecution". The issue here is that during `Parse::catch_inline_exceptions`, the old stack is gone, and we cannot reexecute the current bytecode anymore. However, there are some places where we try to insert safepoints into the graph, such as if the handler is a backward jump, or if one of the exceptions in the handlers is not loaded. Since the `_reexecute` state of the current jvms is "undefined", it is inferred automatically that it should reexecute for some bytecodes such as `putfield`. The solution then is to explicitly set `_reexecute` to false.
>> 
>> I can manage to write a unit test for the case of a backward handler, for the other cases, since the exceptions that can be thrown for a bytecode that is inferred to reexecute are `NullPointerException`, `ArrayIndexOutOfBoundsException`, and `ArrayStoreException`. I find it hard to construct such a test in which one of them is not loaded.
>> 
>> Please kindly review, thanks a lot.
>
> @merykitty , I tried solution 1) and it seems to work, but I think I prefer solution 2) because it aligns better with my idea from JDK-8372846 of canonicalized exception states.  If you like, I can take over this bug.

@dean-long Thanks a lot, please take over this bug then.

> trim stack, throw exception (move to Thread) (reexecute=true)
This requires extra unconditional overhead even though safepoint rarely happens.

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PR Comment: https://git.openjdk.org/jdk/pull/28597#issuecomment-3639912845