RFR: 8342692: C2: long counted loop/long range checks: don't create loop-nest for short running loops [v16]

[Christian Hagedorn]

On Thu, 8 May 2025 10:58:42 GMT, Christian Hagedorn <chagedorn at openjdk.org> wrote:

>> Roland Westrelin has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 43 commits:
>> 
>>  - review
>>  - Merge branch 'master' into JDK-8342692
>>  - merge fix
>>  - Merge branch 'master' into JDK-8342692
>>  - merge fix
>>  - Merge branch 'master' into JDK-8342692
>>  - merge
>>  - Merge branch 'master' into JDK-8342692
>>  - Merge branch 'master' into JDK-8342692
>>  - whitespace
>>  - ... and 33 more: https://git.openjdk.org/jdk/compare/4458719a...ed774a56
>
> src/hotspot/share/opto/loopnode.cpp line 1219:
> 
>> 1217:   const Type* new_phi_t = TypeInt::INT;
>> 1218:   if (profile_short_running_loop) {
>> 1219:     // Add a short_limit predicate. It's the last predicate when coming from the loop because a cast that's control
> 
> I suggest to be consistent with the names to avoid confusion. We could name this "Short Running Long Loop (Parse) Predicate" to be aligned with `Deoptimization::Reason_short_running_long_loop` and the other suggestion in `predicates.hpp` about the predicate block name. What do you think?

I suggest to switch and say: It's the first predicate in the predicate chain before entering a loop [...]

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PR Review Comment: https://git.openjdk.org/jdk/pull/21630#discussion_r2079494161