RFR: 8334629: [BACKOUT] PhaseIdealLoop::conditional_move is too conservative [v2]

[Emanuel Peter]

On Mon, 24 Jun 2024 05:57:54 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

>> Ah yep, looking at the log the main IfNode has `P=0.891189`, so it doesn't succeed the new check `prob > 0.18 && prob < 0.82`. I think this is fundementally the same problem as https://github.com/openjdk/jdk/pull/18734, and increasing the number of predetermined elements ([here](https://github.com/openjdk/jdk/blob/master/test/hotspot/jtreg/compiler/c2/irTests/TestIfMinMax.java#L184-L194)) should fix this. If it's important to get this patch in quickly though feel free to problemlist the test or disable the IR verification, I can take a look at it soon.
>
> @jaskarth Thanks for your analysis, I added the test to the problem list and created a relevant issue for it.

@merykitty testing looks good (only failed for `compiler/c2/irTests/TestIfMinMax.java` but you now problem-listed it).

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PR Comment: https://git.openjdk.org/jdk/pull/19650#issuecomment-2188449333