RFR: 8293484: AArch64: TestUseSHA512IntrinsicsOptionOnSupportedCPU.java fails on CPU with SHA512 feature support

[Andrew Haley]

On Thu, 30 Oct 2025 07:09:38 GMT, Ramkumar Sunderbabu <rsunderbabu at openjdk.org> wrote:

> We have a host of tests under test/hotspot/jtreg/compiler/intrinsics/sha which checks if the SHA intrinsics flags' enable/disable setting is in sync with CPU support in the underlying platform. There might be situations where the intrinsics might not be enabled despite the hardware supporting the relevant instructions. For example, there might be reliability issues or performance issues. In such situations, the tests will fail.
> 
> Till now, the approach has been to exclude the platforms where the support is yet to be provided and remove the exclusion after. This necessitates additional work on the test front.
> 
> A more compact design would be make predicate probes to rely on intrinsics availability in the platform as opposed to hardware support availability. The migration to intrinsics availability would especially help update releases where feature backport might not be complete.
> 
> PS: This fix can/should be propagated to other such tests as well. Once this PR gets approval, I will work on similar tests.

> Hi, I suppose the failure may occur if we run this test case on CPU **with** SHA512 feature, but **disabling** SHA512Intrinsics.
> 
> As **@requires vm.flagless** is set in this jtreg case, if we specify `-XX:-UseSHA512Intrinsics`, this test case is not tested actually. Here shows the log in my machine.
> 
> ```shell
> $ make test TEST=test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA512IntrinsicsOptionOnSupportedCPU.java JTREG="VM_OPTIONS=-XX:-UseSHA512Intrinsics"
> Building target 'test' in configuration '/tmp/local-build-fastdebug'
> Running tests using JTREG control variable 'VM_OPTIONS=-XX:-UseSHA512Intrinsics'
> Test selection 'test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA512IntrinsicsOptionOnSupportedCPU.java', will run:
> * jtreg:test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA512IntrinsicsOptionOnSupportedCPU.java
> Clean up dirs for jtreg_test_hotspot_jtreg_compiler_intrinsics_sha_cli_TestUseSHA512IntrinsicsOptionOnSupportedCPU_java
> 
> Running test 'jtreg:test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA512IntrinsicsOptionOnSupportedCPU.java'
> Test results: no tests selected
> Report written to /tmp/local-build-fastdebug/test-results/jtreg_test_hotspot_jtreg_compiler_intrinsics_sha_cli_TestUseSHA512IntrinsicsOptionOnSupportedCPU_java/html/report.html
> Results written to /tmp/local-build-fastdebug/test-support/jtreg_test_hotspot_jtreg_compiler_intrinsics_sha_cli_TestUseSHA512IntrinsicsOptionOnSupportedCPU_java
> Finished running test 'jtreg:test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA512IntrinsicsOptionOnSupportedCPU.java'
> Test report is stored in /tmp/local-build-fastdebug/test-results/jtreg_test_hotspot_jtreg_compiler_intrinsics_sha_cli_TestUseSHA512IntrinsicsOptionOnSupportedCPU_java
> 
> ==============================
> Test summary
> ==============================
>    TEST                                              TOTAL  PASS  FAIL ERROR  SKIP   
>    jtreg:test/hotspot/jtreg/compiler/intrinsics/sha/cli/TestUseSHA512IntrinsicsOptionOnSupportedCPU.java
>                                                          0     0     0     0     0   
> ==============================
> TEST SUCCESS
> ```
> 
> If so, I don't think it's a bug. Is there anything I misunderstood?

That is correct.


  // Determine if the compiler corresponding to the compilation level 'compLevel'
  // and to the compilation context 'compilation_context' provides an intrinsic
  // for the method 'method'. An intrinsic is available for method 'method' if:
  //  - the intrinsic is enabled (by using the appropriate command-line flag) and
  //  - the platform on which the VM is running provides the instructions necessary
  //    for the compiler to generate the intrinsic code.
  //
  // The compilation context is related to using the DisableIntrinsic flag on a
  // per-method level, see hotspot/src/share/vm/compiler/abstractCompiler.hpp
  // for more details.
  public boolean isIntrinsicAvailable(Executable method,
                                      Executable compilationContext,
                                      int compLevel) {

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PR Comment: https://git.openjdk.org/jdk/pull/28053#issuecomment-3490197209