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

[Christian Ulmann via flang-commits]

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@@ -3842,6 +3901,49 @@ 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);
+    unsigned lastMapBlockArgsIdx =
+        argIface.getMapBlockArgsStart() + argIface.numMapBlockArgs() - 1;
+    OperandRange privateVars = targetOp.getPrivateVars();
+    std::optional<ArrayAttr> privateSyms = targetOp.getPrivateSyms();
+    auto reverseIt = mapVars.rbegin();
+    for (auto [privVar, privSym] :
+         llvm::reverse(llvm::zip_equal(privateVars, *privateSyms))) {
+      SymbolRefAttr privatizerName = llvm::cast<SymbolRefAttr>(privSym);
+      omp::PrivateClauseOp privatizer =
+          findPrivatizer(targetOp, privatizerName);
+      if (!privatizer.needsMap())
+        continue;
+
+      // 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.
+      omp::MapInfoOp mapInfoOp =
+          llvm::cast<omp::MapInfoOp>((*reverseIt).getDefiningOp());
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Dinistro wrote:

`llvm::` should not be necessary, these are re-exported in the `mlir::` namespace.

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