RFR: 8307513: C2: intrinsify Math.max(long,long) and Math.min(long,long) [v12]

[Galder Zamarreño]

On Thu, 27 Feb 2025 06:54:30 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> As for possible solutions. In all Regression 1-3 cases, it seems the issue is scalar cmove. So actually in all cases a possible solution is using branching code (i.e. `cmp+mov`). So to me, these are the follow-up RFE's:
> 
> * Detect "extreme" probability scalar cmove, and replace them with branching code. This should take care of all regressions here. This one has high priority, as it fixes the regression caused by this patch here. But it would also help to improve performance for the `Integer.min/max` cases, which have the same issue.

I've created [JDK-8351409](https://bugs.openjdk.org/browse/JDK-8351409) to address this.

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PR Comment: https://git.openjdk.org/jdk/pull/20098#issuecomment-2706324225