RFR: 8320649: C2: Optimize scoped values [v13]

[Roland Westrelin]

On Thu, 4 Apr 2024 13:30:08 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   test fix
>
> src/hotspot/share/opto/loopnode.cpp line 5193:
> 
>> 5191:       }
>> 5192:       IfNode* iff = hits_in_cache->success_proj()->in(0)->as_If();
>> 5193:       for (uint j = 0; j < _scoped_value_get_nodes.size(); j++) {
> 
> Do you need the whole range? Now you have all i's and all j's. That is intended?

Yes, it's intended. We're looking for a node that dominates `n` and can replace it. So we have to go over all nodes looking for a dominating one and for each `n` we have to check every other node for one that dominates `n` (and can replace it).

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PR Review Comment: https://git.openjdk.org/jdk/pull/16966#discussion_r1553639483