Move non-common files from FortranCommon to FortranSupport (analogous to
LLVMSupport) such that
* declarations and definitions that are only used by the Flang compiler,
but not by the runtime, are moved to FortranSupport
* declarations and definitions that are used by both ("common"), the
compiler and the runtime, remain in FortranCommon
* generic STL-like/ADT/utility classes and algorithms remain in
FortranCommon
This allows a for cleaner separation between compiler and runtime
components, which are compiled differently. For instance, runtime
sources must not use STL's `<optional>` which causes problems with CUDA
support. Instead, the surrogate header `flang/Common/optional.h` must be
used. This PR fixes this for `fast-int-sel.h`.
Declarations in include/Runtime are also used by both, but are
header-only. `ISO_Fortran_binding_wrapper.h`, a header used by compiler
and runtime, is also moved into FortranCommon.
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.
In order to get the pointer to a structure member, `getelementptr`
typically requires two indices: one to indicate the structure itself,
and another to specify the member's position. We are missing the former
in `GPULaunchKernelConversion`, so generated code may cause stack
corruption. This PR corrects the indices of a structure used as a kernel
launch temp.
For the call to _FortranACUFLaunchKernel, we store the pointer to a
member of a temporary structure in a parameter array. However, when we
obtain an element pointer from the parameter array, its address is
calculated based on the type of the structure. This PR properly treats
the parameter array as an array of pointers.
Example:
```mlir
%30 = llvm.load %29 : !llvm.ptr -> i32
%31 = llvm.mlir.constant(1 : i32) : i32
%32 = llvm.alloca %31 x !llvm.struct<(i64, i64, i32, ptr)> : (i32) -> !llvm.ptr
%33 = llvm.mlir.constant(4 : i32) : i32
%34 = llvm.alloca %33 x !llvm.ptr : (i32) -> !llvm.ptr
%35 = llvm.mlir.constant(0 : i32) : i32
%36 = llvm.getelementptr %32[%35] : (!llvm.ptr, i32) -> !llvm.ptr, !llvm.struct<(i64, i64, i32, ptr)>
llvm.store %8, %36 : i64, !llvm.ptr
%37 = llvm.getelementptr %34[%35] : (!llvm.ptr, i32) -> !llvm.ptr, !llvm.struct<(i64, i64, i32, ptr)>
llvm.store %36, %37 : !llvm.ptr, !llvm.ptr
...
llvm.call @_FortranACUFLaunchKernel(%47, %8, %8, %8, %2, %8, %8, %7, %34, %48) : (!llvm.ptr, i64, i64, i64, i64, i64, i64, i32, !llvm.ptr, !llvm.ptr) -> ()
```
In this example, `%37 = llvm.getelementptr %34[%35] : (!llvm.ptr, i32)
-> !llvm.ptr, !llvm.struct<(i64, i64, i32, ptr)>` will be `%37 =
llvm.getelementptr %34[%35] : (!llvm.ptr, i32) -> !llvm.ptr, !llvm.ptr`.
Kernel launch in CUF are converted to `gpu.launch_func`. When the kernel
has `cluster_dims` specified these get carried over to the
`gpu.launch_func` operation. This patch updates the special conversion
of `gpu.launch_func` when cluster dims are present to the newly added
entry point.
