RFR: 8361582: AArch64: Some ConH values cannot be replicated with SVE [v7]

[Bhavana Kilambi]

On Wed, 20 Aug 2025 13:12:45 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> test/hotspot/jtreg/compiler/c2/aarch64/TestFloat16Replicate.java line 30:
>> 
>>> 28: * @modules jdk.incubator.vector
>>> 29: * @library /test/lib /
>>> 30: * @run main/othervm compiler.c2.aarch64.TestFloat16Replicate
>> 
>> I would prefer if this test was also run on other platforms, and not just aarch64. There are other platforms that have Float16 backend instructions.
>
> It's fine if the IR rule is only for SVE, but other platforms could at least encounter the code shape and be tested for correctness.

This type of pattern/code shape where one of the inputs is a constant is already being tested in https://github.com/openjdk/jdk/blob/e912977a6687917ed45520c4d8558ebe630e3f52/test/hotspot/jtreg/compiler/vectorization/TestFloat16VectorOperations.java#L335

I have created this one specifically for aarch64 to ensure both the backend mach nodes are correctly being generated.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26589#discussion_r2288224592