Integrated: 8334629: [BACKOUT] PhaseIdealLoop::conditional_move is too conservative

[Quan Anh Mai]

On Tue, 11 Jun 2024 11:06:11 GMT, Quan Anh Mai <qamai at openjdk.org> wrote:

> Hi,
> 
> I cannot explain the regression, comparing the current mainline to JDK-21 reveals a decrease in performance, yet it is only for some combinations of OS-GC and perfasm shows that the hot regions (>99% of execution time) do not contain differences that can explain the results.
> 
> Consequently, with the advice of @TobiHartmann , I propose to effectively revert JDK-8319451 for the generation of `CMove`s inside loops. For those outside, the before-JDK-8319451 probability threshold is 0.001 and the current value is 0.01. I think the current value is more reasonable as evidenced by the benchmark added in JDK-8319451.
> 
> Please kindly review, thank you very much.
> Quan Anh

This pull request has now been integrated.

Changeset: 933eabab
Author:    Quan Anh Mai <qamai at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/933eababf2b79586a911082af36fdcc41763c7b9
Stats:     75 lines in 3 files changed: 10 ins; 61 del; 4 mod

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

Reviewed-by: epeter, thartmann, jkarthikeyan

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PR: https://git.openjdk.org/jdk/pull/19650