[flang-commits] [flang] [llvm] [mlir] [mlir][OpenMP] - MLIR to LLVMIR translation support for delayed privatization of allocatables in `omp.target` ops (PR #116576)

[Sergio Afonso via flang-commits]

================
@@ -3840,6 +3885,58 @@ convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
   bool isOffloadEntry =
       isTargetDevice || !ompBuilder->Config.TargetTriples.empty();
 
+  // For some private variables, the MapsForPrivatizedVariablesPass
+  // creates MapInfoOp instances. Go through the private variables and
+  // the mapped variables so that during codegeneration we are able
+  // to quickly look up the corresponding map variable, if any for each
+  // private variable.
+  if (!targetOp.getPrivateVars().empty() && !targetOp.getMapVars().empty()) {
+    auto argIface = llvm::cast<omp::BlockArgOpenMPOpInterface>(*targetOp);
+    OperandRange privateVars = targetOp.getPrivateVars();
+    std::optional<ArrayAttr> privateSyms = targetOp.getPrivateSyms();
+    std::optional<DenseI64ArrayAttr> privateMapIndices =
+        targetOp.getPrivateMapsAttr();
+
+    for (auto [privVarIdx, privVarSymPair] :
+         llvm::enumerate(llvm::zip_equal(privateVars, *privateSyms))) {
+      auto privVar = std::get<0>(privVarSymPair);
+      auto privSym = std::get<1>(privVarSymPair);
+
+      SymbolRefAttr privatizerName = llvm::cast<SymbolRefAttr>(privSym);
+      omp::PrivateClauseOp privatizer =
+          findPrivatizer(targetOp, privatizerName);
+
+      if (!privatizer.needsMap())
+        continue;
+
+      mlir::Value mappedValue =
+          targetOp.getMappedValueForPrivateVar(privVarIdx);
+      assert(mappedValue && "Expected to find mapped value for a privatized "
+                            "variable that needs mapping");
+
+      // The MapInfoOp defining the map var isn't really needed later.
+      // So, we don't store it in any datastructure. Instead, we just
+      // do some sanity checks on it right now.
+      auto mapInfoOp = mappedValue.getDefiningOp<omp::MapInfoOp>();
+      Type varType = mapInfoOp.getVarType();
+
+      // Check #1: Check that the type of the private variable matches
+      // the type of the variable being mapped.
+      if (!isa<LLVM::LLVMPointerType>(privVar.getType()))
+        assert(
+            varType == privVar.getType() &&
+            "Type of private var doesn't match the type of the mapped value");
+
+      // Ok, only 1 sanity check for now.
+      // Record the index of the block argument corresponding to this
+      // mapvar.
----------------
skatrak wrote:

```suggestion
      // Record the block argument corresponding to this mapvar.
```

https://github.com/llvm/llvm-project/pull/116576