RFR: 8314191: C2 compilation fails with "bad AD file" [v3]

[Quan Anh Mai]

On Tue, 5 Sep 2023 00:44:18 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

>> Hi,
>> 
>> The root cause is that the comparison in the form `x + inc <=> bound` being transformed into `x u<=> bound - min_value` when `inc` is the min value of the loop type. The fix I propose is to avoid the transformation when either side is a counted loop increment.
>> 
>> Thanks a lot.
>
> Quan Anh Mai has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
> 
>  - Merge branch 'master' into ucountedloop
>  - TraceLoopOpt not needed
>  - fix tests
>  - add test
>  - should not transform into unsigned comparison if either side is a loop increment variable

The failures in CI are due to [JDK-8315696](https://bugs.openjdk.org/browse/JDK-8315696).

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PR Comment: https://git.openjdk.org/jdk/pull/15551#issuecomment-1706934998