RFR: 8307084: C2: Vectorized drain loop is not executed for some small trip counts [v4]

[Fei Gao]

On Wed, 21 Jan 2026 10:35:59 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Fei Gao has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 13 commits:
>> 
>>  - Fix build failure after rebasing and address review comments
>>  - Merge branch 'master' into optimize-atomic-post
>>  - Fixed new test failures after rebasing and refined parts of the code to address review comments
>>  - Merge branch 'master' into optimize-atomic-post
>>  - Merge branch 'master' into optimize-atomic-post
>>  - Clean up comments for consistency and add spacing for readability
>>  - Fix some corner case failures and refined part of code
>>  - Merge branch 'master' into optimize-atomic-post
>>  - Refine ascii art, rename some variables and resolve conflicts
>>  - Merge branch 'master' into optimize-atomic-post
>>  - ... and 3 more: https://git.openjdk.org/jdk/compare/a8552243...ab1de504
>
> test/micro/org/openjdk/bench/vm/compiler/VectorThroughputForIterationCount.java line 282:
> 
>> 280:             byteadd(aB, bB, rB, START_IDX, offsets[r]+ITERATION_COUNT);
>> 281:         }
>> 282:     }
> 
> Why do you name them `drain`? I feel the name is a bit too specific to "this patch". Do you have a better name?
> Maybe a name that separates them from `bench011B_aligned_memoryBound`?

As discussed in the refined comments above, I’ll rename them to `bench03xx_staticTripCount `and `bench03xx_dynamicTripCount`. What do you think?

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PR Review Comment: https://git.openjdk.org/jdk/pull/22629#discussion_r2717371113