[flang][cuda] Lower shared global to the correct NVVM address space (#131368)

Global with the CUDA shared data attribute needs to be lowered to llvm
globals with the correct address space (3). Address space is set from
the `mlir::NVVM::NVVMMemorySpace::kSharedMemorySpace` enum from
`mlir/Dialect/LLVMIR/NVVMDialect.h`

Author: clementval

flang/lib/Optimizer/CodeGen/CodeGen.cpp

@@ -47,6 +47,7 @@
 #include "mlir/Dialect/GPU/IR/GPUDialect.h"
 #include "mlir/Dialect/LLVMIR/LLVMAttrs.h"
 #include "mlir/Dialect/LLVMIR/LLVMDialect.h"
+#include "mlir/Dialect/LLVMIR/NVVMDialect.h"
 #include "mlir/Dialect/LLVMIR/Transforms/AddComdats.h"
 #include "mlir/Dialect/OpenACC/OpenACC.h"
 #include "mlir/Dialect/OpenMP/OpenMPDialect.h"
@@ -3145,6 +3146,11 @@ struct GlobalOpConversion : public fir::FIROpConversion<fir::GlobalOp> {
         }
       }
     }
+
+    if (global.getDataAttr() &&
+        *global.getDataAttr() == cuf::DataAttribute::Shared)
+      g.setAddrSpace(mlir::NVVM::NVVMMemorySpace::kSharedMemorySpace);
+
     rewriter.eraseOp(global);
     return mlir::success();
   }

flang/test/Fir/CUDA/cuda-code-gen.mlir

@@ -198,3 +198,9 @@ func.func @_QMm1Psub1(%arg0: !fir.box<!fir.array<?xi32>> {cuf.data_attr = #cuf.c
 
 // CHECK-LABEL: llvm.func @_QMm1Psub1
 // CHECK-COUNT-2: _FortranACUFAllocDescriptor
+
+// -----
+
+fir.global common @_QPshared_static__shared_mem(dense<0> : vector<28xi8>) {alignment = 8 : i64, data_attr = #cuf.cuda<shared>} : !fir.array<28xi8>
+
+// CHECK: llvm.mlir.global common @_QPshared_static__shared_mem(dense<0> : vector<28xi8>) {addr_space = 3 : i32, alignment = 8 : i64} : !llvm.array<28 x i8>