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

[via flang-commits]

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@@ -1710,30 +1710,76 @@ 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::ValueRange bounds, std::string asFortran,
+    llvm::omp::OpenMPOffloadMappingFlags mapCaptureType) {
+  llvm::SmallVector<mlir::Value> descriptorBaseAddrMembers;
+  fir::FirOpBuilder &firOpBuilder = converter.getFirOpBuilder();
+
+  mlir::Value descriptor = descriptorAddr;
+
+  // The fir::BoxOffsetOp only works with !fir.ref<!fir.box<...>> types, as
+  // allowing it to access non-reference box operations can cause some
+  // problematic SSA IR. However, in the case of assumed shape's the type
+  // is not a !fir.ref, in these cases to retrieve the appropriate
+  // !fir.ref<!fir.box<...>> to access the data we need to map we must
+  // perform an alloca and then store to it and retrieve the data from the new
+  // alloca.
+  if (fir::isAssumedShape(fir::unwrapRefType(descriptorAddr.getType()))) {
+    mlir::OpBuilder::InsertPoint insPt = firOpBuilder.saveInsertionPoint();
+    firOpBuilder.setInsertionPointToStart(firOpBuilder.getAllocaBlock());
+    descriptor =
+        firOpBuilder.create<fir::AllocaOp>(loc, descriptorAddr.getType());
+    firOpBuilder.restoreInsertionPoint(insPt);
+    firOpBuilder.create<fir::StoreOp>(loc, descriptorAddr, descriptor);
----------------
agozillon wrote:

However, what is currently being done with the assumed shape arrays is creating an allocation, that we can effectively store the passed in box data to and then utilise the box offset op on to retrieve the underlying data pointer, there may be a better way of doing this however, or an extremely obvious way of doing it that I am missing :) 

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