RFR: 8295166: IGV: dump graph at more locations

[Christian Hagedorn]

On Fri, 13 Oct 2023 11:26:23 GMT, Daniel Lundén <duke at openjdk.org> wrote:

>> src/hotspot/share/opto/compile.cpp line 5115:
>> 
>>> 5113:   print_method(cpt, level, n, iter);
>>> 5114: #else
>>> 5115:   print_method(cpt, level, n);
>> 
>> This is dead code because all calls are guarded by `NOT_PRODUCT`, right?
>
> Not quite, there is one unguarded call for `PHASE_PHASEIDEALLOOP_ITERATIONS` at level 2. This is an existing phase that I converted from `print_method` to `print_method_iter` (as suggested by @chhagedorn in the issue corresponding to this PR).

The current rule seems to be that we always want to emit a JFR event when dumping a graph - regardless of whether we dump a graph or not. I think we should follow this convention and remove the `NOT_PRODUCT` from the calls to `print_method_iter()`.

On a separate note, I'm wondering how useful it is to always dump all events when calling `print_method()`. Should this be revisited again in general?

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PR Review Comment: https://git.openjdk.org/jdk/pull/16120#discussion_r1380459903