RFR: 8309109: AArch64: [TESTBUG] compiler/intrinsics/sha/cli/TestUseSHA3IntrinsicsOptionOnSupportedCPU.java fails on Neoverse N2 and V1

[Andrew Haley]

On Tue, 20 Jun 2023 06:35:15 GMT, Hao Sun <haosun at openjdk.org> wrote:

> `UseSHA3Intrinsics` was introduced in JDK-8252204, but it was not auto-enabled due to the lack of real hardware. In JDK-8297092, the intrinsic was evaluated on existing hardware with the support of SHA3 feature (including Neoverse N2/V1 and Apple silicon), and it was auto-enabled by default on Apple silicon only. See the code [1].
> 
> As a result, test case `TestUseSHA3IntrinsicsOptionOnSupportedCPU.java` fails on Neoverse N2 and V1 with the following error message:
> 
> 
> JavaTest Message: Test threw exception: java.lang.AssertionError: Option 'UseSHA3Intrinsics' is expected to have 'true' value
> Option 'UseSHA3Intrinsics' should be enabled by default
> 
> 
> The group of test cases `TestUseXXXIntrinsicsOptionOnSupportedCPU.java` are designed to verify that, option `UseXXXIntrinsics` should be enabled by default if the underlying hardware supports the corresponding CPU feature.
> 
> Apparently this check condition doesn't work for `UseSHA3Intrinsics`. The other expcetion case is `UseSHA512Intrinsics`. See JDK-8257796.
> 
> Fix: One `@requires` condition is added in this patch to limit that this test case is only run on macOS on Apple silicon. Note that SHA3 feature is currently supported by AArch64 only.
> 
> Test: this test case passed on Linux/Neoverse N2, Linux/Neoverse V1 and macOS on Apple silicon.
> 
> [1] https://github.com/openjdk/jdk/pull/11382/files#diff-a87e260510f34ca7d9b0feb089ad982be8268c5c8aa5a71221f6738b051ea488R338-R345

test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA3IntrinsicsOptionOnSupportedCPU.java line 31:

> 29:  * @library /test/lib /
> 30:  * @requires vm.flagless
> 31:  * @requires os.arch == "aarch64" & os.family == "mac"

I think this requires a comment. Something to the effect that we don't always enable the use of SHA3 instructions because they don't always help.

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PR Review Comment: https://git.openjdk.org/jdk/pull/14551#discussion_r1234931737