RFR: JDK-8287061: Support for rematerializing scalar replaced objects participating in allocation merges [v13]

Thu May 25 22:54:15 UTC 2023

On Mon, 22 May 2023 17:56:41 GMT, Cesar Soares Lucas <cslucas at openjdk.org> wrote:

>> Are you sure there's no way to end up with nested ObjectMergeValues in presence of iterative EA?
> I don't think so. 

Ok. Please, add asserts to catch such situation and a check which bails out compilation (triggering recompilation w/ ReduceAllocationMerges turned off) if it happens with product binaries.

> So, the way I test that deoptimization worked is basically just making sure the tests that "deoptimize" have the same output with RAM enabled and disabled.

Please, enhance `AllocationMergesTests` to cover deoptimization (e.g., using WhiteBox API or additional run w/ -XX:+DeoptimizeALot) and ensure that tests are sensitive enough to fail when wrong state is rematerialized.

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PR Comment: https://git.openjdk.org/jdk/pull/12897#issuecomment-1559847061
PR Comment: https://git.openjdk.org/jdk/pull/12897#issuecomment-1559852990