RFR: 8329077: C2 SuperWord: Add MoveD2L, MoveL2D, MoveF2I, MoveI2F [v3]

[Galder Zamarreño]

On Sun, 10 Aug 2025 05:23:23 GMT, Emanuel Peter <epeter at openjdk.org> wrote:

>> Galder Zamarreño has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   Check at the very least that auto vectorization is supported
>
> src/hotspot/share/opto/superword.cpp line 1635:
> 
>> 1633:     } else if (VectorNode::is_convert_opcode(opc)) {
>> 1634:       retValue = VectorCastNode::implemented(opc, size, velt_basic_type(p0->in(1)), velt_basic_type(p0));
>> 1635:     } else if (VectorNode::is_reinterpret_opcode(opc)) {
> 
> How does this affect `Op_ReinterpretHF2S` that is also in `VectorNode::is_reinterpret_opcode`?
> I'm afraid that we need to test this with hardware or Intel's SDE, to make sure we have it running on a VM that actually supports Float16. Otherwise these instructions may not be used, and hence not tested right.
> 
> @galderz Can you run the relevant tests?

Would you run specific tiers in those platforms? Just hotspot compiler? Or individual tests such as `ConvF2HFIdealizationTests` and `TestFloat16ScalarOperations`?

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PR Review Comment: https://git.openjdk.org/jdk/pull/26457#discussion_r2266889792