Integrated: 8348570: CTW: Expose the code hidden by uncommon traps

[Aleksey Shipilev]

On Fri, 24 Jan 2025 11:15:33 GMT, Aleksey Shipilev <shade at openjdk.org> wrote:

> We have been looking at some related compiler behaviors, and realized that in the absence of profiling data, C2 routinely uncommon-traps a lot of code that is presumed to be never executed. This apparently is a norm in CTW tests: CTW runners never execute code, and so only the most basic java.base classes are having any profile. This seems to limit the scope of CTW testing.
> 
> I think we need to run CTW in the mode that exposes more code to the compiler optimizations.
> 
> Case in point: [JDK-8348572](https://bugs.openjdk.org/browse/JDK-8348572), which reliably fails with more aggressive compilation mode. 
> 
> Additional testing:
>  - [x] Linux x86-64 server fastdebug, `applications/ctw/modules`
>  - [x] Linux AArch64 server fastdebug, `applications/ctw/modules`

This pull request has now been integrated.

Changeset: 10791477
Author:    Aleksey Shipilev <shade at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/10791477cf0a0a31d2703fc718a7a649d494d534
Stats:     22 lines in 2 files changed: 20 ins; 0 del; 2 mod

8348570: CTW: Expose the code hidden by uncommon traps

Reviewed-by: kvn, thartmann

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PR: https://git.openjdk.org/jdk/pull/23296