[llvm-branch-commits] [OpenMP][MLIR] Add new arguments to map_info to help support record type maps (PR #82851)

[via llvm-branch-commits]

agozillon wrote:

So, incremental increase of support if possible and get feedback as early as possible on direction is the aim :-)

The idea for the member index, at least currently will be to move it to a multi-dimensional index (via DenseIntElementsAttr) as an example:

```
type :: nested
    real(4) :: x1
    real(4) :: y2
    real(4) :: z3
end type nested

type :: array
  real(4) :: x
  real(4) :: y
  real(4) :: z
  type(nested) :: nest 
end type array

```

In the above case array%nest would be index: (3) and array%nest%z3 would be index: (3, 2), if we replaced z3 with another layer through a derived type and mapped a member of it, it would be an index of (3, 2, ...) and so on.

I am hoping that will be reasonable enough to support the case of map(tofrom: x%y%z, x%y) and from a little IR testing it seems it should be, however, I am still working on the initial implementation for this use-case, so I could be wrong. The main thing I am worried about and a little unsure on currently is if the layout of the derived type will always be segmentable like this. But there could be other things wrong with modeling the placement of members like this that I am missing (or a better method of doing so)! So if there is I would love for some feedback.   

https://github.com/llvm/llvm-project/pull/82851