[llvm-branch-commits] [flang] [Flang][OpenMP] Derived type explicit allocatable member mapping (PR #96266)

[Sergio Afonso via llvm-branch-commits]

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@@ -51,21 +55,66 @@ class OMPMapInfoFinalizationPass
     : public fir::impl::OMPMapInfoFinalizationPassBase<
           OMPMapInfoFinalizationPass> {
 
-  void genDescriptorMemberMaps(mlir::omp::MapInfoOp op,
-                               fir::FirOpBuilder &builder,
-                               mlir::Operation *target) {
-    mlir::Location loc = op.getLoc();
-    mlir::Value descriptor = op.getVarPtr();
+  /// Small helper class tracking a members parent and its
+  /// placement in the parents member list
+  struct ParentAndPlacement {
+    mlir::omp::MapInfoOp parent;
+    size_t index;
+  };
 
-    // If we enter this function, but the mapped type itself is not the
-    // descriptor, then it's likely the address of the descriptor so we
-    // must retrieve the descriptor SSA.
-    if (!fir::isTypeWithDescriptor(op.getVarType())) {
-      if (auto addrOp = mlir::dyn_cast_if_present<fir::BoxAddrOp>(
-              op.getVarPtr().getDefiningOp())) {
-        descriptor = addrOp.getVal();
+  /// getMemberUserList gathers all users of a particular MapInfoOp that are
+  /// other MapInfoOp's and places them into the mapMemberUsers list, which
+  /// records the map that the current argument MapInfoOp "op" is part of
+  /// alongside the placement of "op" in the recorded users members list. The
+  /// intent of the generated list is to find all MapInfoOp's that may be
+  /// considered parents of the passed in "op" and in which it shows up in the
+  /// member list, alongside collecting the placement information of "op" in its
+  /// parents member list.
+  void
+  getMemberUserList(mlir::omp::MapInfoOp op,
+                    llvm::SmallVectorImpl<ParentAndPlacement> &mapMemberUsers) {
+    for (auto *users : op->getUsers())
+      if (auto map = mlir::dyn_cast_if_present<mlir::omp::MapInfoOp>(users))
+        for (size_t i = 0; i < map.getMembers().size(); ++i)
+          if (map.getMembers()[i].getDefiningOp() == op)
+            mapMemberUsers.push_back({map, i});
+  }
+
+  /// This function will expand a MapInfoOp's member indices back into a vector
+  /// so that they can be trivially modified as unfortunately the attribute type
+  /// that's used does not have modifiable fields at the moment (generally
+  /// awkward to work with)
+  void getMemberIndicesAsVectors(
+      mlir::omp::MapInfoOp mapInfo,
+      llvm::SmallVector<llvm::SmallVector<int32_t>> &indices) {
+    size_t row = 0;
+    size_t shapeX = mapInfo.getMembersIndexAttr().getShapedType().getShape()[0];
+    size_t shapeJ = mapInfo.getMembersIndexAttr().getShapedType().getShape()[1];
+
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skatrak wrote:

Nit: `indices.reserve(indices.size() + shapeX);`

https://github.com/llvm/llvm-project/pull/96266