[lworld+vector] RFR: Merge lworld

[Jatin Bhateja]

On Sun, 25 Jun 2023 06:20:22 GMT, Xiaohong Gong <xgong at openjdk.org> wrote:

> For the scalarization changes on multifields https://github.com/jatin-bhateja/valhalla/blob/84b3b1e11cdef2c870d1f430c7db2ae60f752d5f/src/hotspot/share/opto/inlinetypenode.cpp#L327, you'v assumed that multifields are used for `vector_payload` or `vector_payload_mf` classes. Although it is true currently, it will be more reasonable if we scalarize the `InlineTypeNode` without such assumptions. What about if multifields are used elsewhere?

Yes, I plan to address this after this merge, currently there is a discrepancy b/w field count returned by _ciInstanceKlass::nof_nonstatic_fields()_  vs  InlineTypeNode::field_count(),  this is because ci* data model directly works over oops data model which is populated by classFileParser, thus a multifield is a regular field  @multifield annotation, its only during c2 parsing we scalarize it. 

We will need to add a new interface to query supported vector size in ciInstance which is implemented by both the compilers, this will be used to return correct field count which matches with IR.

-------------

PR Comment: https://git.openjdk.org/valhalla/pull/866#issuecomment-1606151091