RFR: 8367899: compiler/c2/gvn/TestBitCompressValueTransform.java intermittent timed out [v2]

[Christian Hagedorn]

On Tue, 30 Sep 2025 06:33:28 GMT, SendaoYan <syan at openjdk.org> wrote:

>> Hi all,
>> 
>> After JDK-8260555 change the timeout factor from 4 to 1, make test compiler/c2/gvn/TestBitCompressValueTransform.java intermittent timed out.
>> 
>> There are 20 10k/20k loop count of loops in this test, this cause test need many CPU cycles to finish. If I reduce the loop count from 10k/20k to 100/200, the test failures descripted in [JDK-8350896](https://bugs.openjdk.org/browse/JDK-8350896) also reproduced when the tested jdk is jdk25u. So it seems that there no need so many loop count for these tests.
>> 
>> Without the proposed change, the driver action finish about 65 sencods on linux-x64, with the proposed change the driver action finish about 1.5 seconds.
>
> SendaoYan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Remove the loop which do not use the loop variable i or do not use random number

Removing the loops looks good! As pointed out by @dafedafe, the IR framework will indeed take care of warming the tests up.

test/hotspot/jtreg/compiler/c2/gvn/TestBitCompressValueTransform.java line 78:

> 76: 
> 77:     @Run(test = "test1")
> 78:     public void run1(RunInfo info) {

While at it, you can also remove all the unused `RunInfo` parameters. But up to you if you want to squeeze that in here as well - it's only a clean-up that is not that important.

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Marked as reviewed by chagedorn (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27548#pullrequestreview-3303110818
PR Review Comment: https://git.openjdk.org/jdk/pull/27548#discussion_r2405139254