RFR: 8295166: IGV: dump graph at more locations [v2]

[Daniel Lundén]

On Thu, 7 Dec 2023 07:52:40 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> Daniel Lundén has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Address comments
>
> src/hotspot/share/opto/split_if.cpp line 595:
> 
>> 593: void PhaseIdealLoop::do_split_if(Node* iff, RegionNode** new_false_region, RegionNode** new_true_region) {
>> 594: 
>> 595:   C->print_method(PHASE_BEFORE_SPLIT_IF, 4, iff);
> 
> We call `do_split_if()` for the actual split if here:
> https://github.com/openjdk/jdk/blob/632a3c56e0626b4c4f79c8cb3d2ae312668d63fc/src/hotspot/share/opto/loopopts.cpp#L1448-L1450
> 
> but also to merge identical back to back ifs here:
> 
> https://github.com/openjdk/jdk/blob/632a3c56e0626b4c4f79c8cb3d2ae312668d63fc/src/hotspot/share/opto/loopopts.cpp#L1529-L1545
> 
> I think we should only track the "real" split ifs done in the former case. Should we move this and the `tty` printing to L1448? But could also be done separately.
> 
> On a separate note, I think we do not need the printing twice and can merge these two lines as well when doing this change:
> 
>   if (PrintOpto && VerifyLoopOptimizations) {
>     tty->print_cr("Split-if");
>   }
>   if (TraceLoopOpts) {
>     tty->print_cr("SplitIf");
>   }

Sounds good to me; I've made the changes now. @chhagedorn, please check so that I've not misunderstood anything.

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PR Review Comment: https://git.openjdk.org/jdk/pull/16120#discussion_r1418691898