[flang-commits] [openmp] [mlir] [flang] [Flang][OpenMP] Initial mapping of Fortran pointers and allocatables for target devices (PR #71766)

[via flang-commits]

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@@ -1710,30 +1710,82 @@ bool ClauseProcessor::processLink(
 
 static mlir::omp::MapInfoOp
 createMapInfoOp(fir::FirOpBuilder &builder, mlir::Location loc,
-                mlir::Value baseAddr, std::stringstream &name,
-                mlir::SmallVector<mlir::Value> bounds, uint64_t mapType,
-                mlir::omp::VariableCaptureKind mapCaptureType,
-                mlir::Type retTy) {
-  mlir::Value varPtr, varPtrPtr;
-  mlir::TypeAttr varType;
-
+                mlir::Value baseAddr, mlir::Value varPtrPtr, std::string name,
+                mlir::SmallVector<mlir::Value> bounds,
+                mlir::SmallVector<mlir::Value> members, uint64_t mapType,
+                mlir::omp::VariableCaptureKind mapCaptureType, mlir::Type retTy,
+                bool isVal = false) {
   if (auto boxTy = baseAddr.getType().dyn_cast<fir::BaseBoxType>()) {
     baseAddr = builder.create<fir::BoxAddrOp>(loc, baseAddr);
     retTy = baseAddr.getType();
   }
 
-  varPtr = baseAddr;
-  varType = mlir::TypeAttr::get(
+  mlir::TypeAttr varType = mlir::TypeAttr::get(
       llvm::cast<mlir::omp::PointerLikeType>(retTy).getElementType());
 
   mlir::omp::MapInfoOp op = builder.create<mlir::omp::MapInfoOp>(
-      loc, retTy, varPtr, varType, varPtrPtr, bounds,
+      loc, retTy, baseAddr, varType, varPtrPtr, members, bounds,
       builder.getIntegerAttr(builder.getIntegerType(64, false), mapType),
       builder.getAttr<mlir::omp::VariableCaptureKindAttr>(mapCaptureType),
-      builder.getStringAttr(name.str()));
+      builder.getStringAttr(name));
+
   return op;
 }
 
+static mlir::omp::MapInfoOp processDescriptorTypeMappings(
+    Fortran::semantics::SemanticsContext &semanticsContext,
+    Fortran::lower::StatementContext &stmtCtx,
+    Fortran::lower::AbstractConverter &converter, mlir::Location loc,
+    mlir::Value descriptorAddr, mlir::Value descDataBaseAddr,
+    mlir::SmallVector<mlir::Value> &bounds, std::string asFortran,
+    llvm::omp::OpenMPOffloadMappingFlags mapCaptureType) {
+  llvm::SmallVector<mlir::Value> descriptorBaseAddrMembers;
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+
+  mlir::Value descriptor = descriptorAddr;
+  if (fir::isAssumedShape(fir::unwrapRefType(descriptorAddr.getType()))) {
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agozillon wrote:

It's necessary as these are not `fir.ref<fir.box<.,.>>` types like the allocatables and pointers, they're just `fir.box`'s. Which poses a little bit of a problem as the `fir::BoxOffsetOp` is actually only intended to work with `fir.ref<fir.box<.,.>>`'s. I asked @jeanPerier if it was possible to lower this restriction, but it is unfortunately not as there's some very problematic SSA IR you can generate if we allow non-ref boxes (a little beyond my current understanding). So, the way to use the `fir::BoxOffsetOp` to retrieve the base address in these cases appears to be to generate an intermediate alloca, store to it and then use this to access the required data. This is the method to convert to a `fir.ref<fir.box<.,.>>` that Jean mentioned, but perhaps there's another method to do so.  

I'll add a comment to describe this inline.

https://github.com/llvm/llvm-project/pull/71766