RFR: 8355488: Add stress mode for C2 loop peeling [v3]

[Marc Chevalier]

On Thu, 15 May 2025 12:19:05 GMT, Tobias Hartmann <thartmann at openjdk.org> wrote:

>> Marc Chevalier has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Back to PRODUCT for consistency
>
> src/hotspot/share/opto/loopTransform.cpp line 522:
> 
>> 520:       loop_head->_peeling_opportunities_count++;
>> 521:       // In case of stress, let's just pick randomly...
>> 522:       return phase->C->random() % 2 == 0 ? estimate : 0;
> 
> Suggestion:
> 
>       return ((phase->C->random() % 2) == 0) ? estimate : 0;

Done. But does that really helps you? To me it's just more confusing. It looks like "I put parentheses because it will associate in a surprising way", and then the most normal things comes. I often wonder whether the parentheses are misplaced, or whether there is something subtle I don't get.
But anyway, parentheses are in!

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PR Review Comment: https://git.openjdk.org/jdk/pull/25140#discussion_r2092532652