RFR: 8325520: Vector loads with offsets incorrectly compiled

[Emanuel Peter]

On Wed, 27 Mar 2024 09:14:57 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

> It seems that your code would now disallow such a case, because you always check that the Ideal node you get back is of the same type as the this node. Am I right about that? Is that intended?

If I am right that you would have made such a optimization impossible, that probably means that our tests don't have an IR test that cover this case. You would definitely need to add such IR tests, otherwise we don't know if we are getting regressions. You will probably also have to run this patch through performance testing eventually.

> I've tried to use the IR framework to check for folded/non folded nodes but couldn't make it reliable enough (in the end it didn't test more than the current test). So I decided to go back to the actual "regression" test which reproduces the original issue.

Do you know what is the issue with reliability for the IR rules? Why did it not always work?

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PR Comment: https://git.openjdk.org/jdk/pull/18347#issuecomment-2022281797