8258412: [lworld] TestArrays::test73 fails due to unexpected result

[TobiHartmann]

TestArrays::test73 spuriously failed (only) with a product build. I finally figured out that with a product build the -XX:-MonomorphicArrayCheck flag specified by the test is ignored which is required to trigger the problem. Instead of adding yet another scenario to our tests, I've added a PreferCommandLineFlags option to the framework to allow overwriting scenario flags by flags set via the command line. I'll use it for testing some more flag combinations in the CI.

The root cause of the issue is that for a flat array store the MonomorphicArrayCheck optimization updates the array type to the exact (flat) type but does not update the corresponding element type. As a result, elemtype->inline_klass()->is_empty() returns true in product leading to incorrect execution and hits an assert in debug because elemtype is general java.lang.Object.

I've also fixed another issue in Parse::array_store_check() and added some asserts to catch similar issues earlier in the future.

Thanks,
Tobias

---

Progress

• Change must not contain extraneous whitespace

Issue

• JDK-8258412: [lworld] TestArrays::test73 fails due to unexpected result

Download

$ git fetch https://git.openjdk.java.net/valhalla pull/303/head:pull/303
$ git checkout pull/303

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[openjdk]

@TobiHartmann This change now passes all automated pre-integration checks.

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8258412: [lworld] TestArrays::test73 fails due to unexpected result

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[mlbridge]

Webrevs

• 00: Full (ebb6320)

[TobiHartmann]

/integrate

[openjdk]

@TobiHartmann Pushed as commit 56ddef2.

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