On Fri, 19 Dec 2025 06:26:47 GMT, Jatin Bhateja <[email protected]> wrote:
>>> > The basic type codes are declared and shared across Java and HotSpot -
>>> > it's used in `LaneType`. Can we pass a single argument that is the basic
>>> > type instead of two arguments. HotSpot should know from the basic type
>>> > what the carrier class and also what the operation type without it being
>>> > explicitly told, since presumably it knew the inverse - the basic type
>>> > from the element class.
>>>
>>> Hi @PaulSandoz, T_HALFFLOAT used in LaneType is mainly used for
>>> differentiation of various cache keys used by conversion operation lookups.
>>> In principle, we can extend VM to acknowledge this new custom basic type on
>>> the lines of T_METADATA / T_ADDRESS; its scope for now will be restricted
>>> to VectorSupport. We can gradually expose this to C2 type, such that
>>> TypeVect for all Float16 VectorIR uses T_HALFFLOAT as its basic type;
>>> currently, we use T_SHORT as the lane type. Let me know if this looks
>>> reasonable
>>
>> I am proposing something simpler, really as a temporary step until `Float16`
>> becomes part of the `java.base` module. IIUC from the basic type we can
>> reliably determine what the two arguments we currently passing are e.g.,
>> T_HALFFLOAT = { short.class, VECTOR_TYPE_FP16 }. So we don't need to pass
>> two arguments, we can just pass one, the intrinsic can lookup the class and
>> operation type kind.
>
> Hi @PaulSandoz , your comments have been addressed. Please let us know if
> there are other comments.
> Hi @eme64 , Kindly share your comments.
@jatin-bhateja Thanks for the ping! I'll put this on the list for review early
in 2026 :)
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PR Comment: https://git.openjdk.org/jdk/pull/28002#issuecomment-3673842243
