As there is now certain areas where we now have the possibility of
having either a ModuleOp or GPUModuleOp and both of these modules can
have DataLayout's and we may require utilising the DataLayout utilities
in these areas I've taken the liberty of trying to extend them for use
with both.
Those with more knowledge of how they wish the GPUModuleOp's to interact
with their parent ModuleOp's DataLayout may have further alterations
they wish to make in the future, but for the moment, it'll simply
utilise the basic data layout construction which I believe combines
parent and child datalayouts from the ModuleOp and GPUModuleOp. If there
is no GPUModuleOp DataLayout it should default to the parent ModuleOp.
It's worth noting there is some weirdness if you have two module
operations defining builtin dialect DataLayout Entries, it appears the
combinatorial functionality for DataLayouts doesn't support the merging
of these.
This behaviour is useful for areas like:
https://github.com/llvm/llvm-project/pull/119585/files#diff-19fc4bcb38829d085e25d601d344bbd85bf7ef749ca359e348f4a7c750eae89dR1412
where we have a crossroads between the two different module operations.
Introduce cuf.sync_descriptor to be used to sync device global
descriptor after pointer association.
Also move CUFCommon so it can be used in FIRBuilder lib as well.
1. In `CufOpConversion` `isDeviceGlobal` was renamed
`isRegisteredGlobal` and moved to the common file. `isRegisteredGlobal`
excludes constant `fir.global` operation from registration. This is to
avoid calls to `_FortranACUFGetDeviceAddress` on globals which do not
have any symbols in the runtime. This was done for
`_FortranACUFRegisterVariable` in #118582, but also needs to be done
here after #118591
2. `CufDeviceGlobal` no longer adds the `#cuf.cuda<constant>` attribute
to the constant global. As discussed in #118582 a module variable with
the #cuf.cuda<constant> attribute is not a compile time constant. Yet,
the compile time constant also needs to be copied into the GPU module.
The candidates for copy to the GPU modules are
- the globals needing regsitrations regardless of their uses in device
code (they can be referred to in host code as well)
- the compile time constant when used in device code
3. The registration of "constant" module device variables (
#cuf.cuda<constant>) can be restored in `CufAddConstructor`
Global constants have no symbols in library files. They are replaced
with literal constants during lowering before kernels are moved into a
GPU module. Do not register them because they will result in unresolved
symbols.
