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

[Christian Ulmann]

================
@@ -3819,7 +3815,57 @@ createDeviceArgumentAccessor(MapInfoData &mapData, llvm::Argument &arg,
 
   return builder.saveIP();
 }
+/// privatizer is a PrivateClauseOp that privatizes an MLIR value.
+/// privatizerNeedsMap returns true if the value being privatized in an
+/// omp.target p should additionally be mapped to the target region
+/// using a MapInfoOp. This is most common when an allocatable is privatized.
+/// In such cases, the descriptor is use in privatization and needs to be
+/// mapped on to the device.
+// static bool privatizerNeedsMap(omp::PrivateClauseOp &privatizer) {
+//   Region &allocRegion = privatizer.getAllocRegion();
+//   Value blockArg0 = allocRegion.getArgument(0);
+//   return !blockArg0.use_empty();
+// }
+
+/// Return the llvm::Value * corresponding to the privateVar that
+/// is being privatized. It isn't always as simple as looking up
+/// moduleTranslation with privateVar. For instance, in case of
+/// an allocatable, the descriptor for the allocatable is privatized.
+/// This descriptor is mapped using an MapInfoOp. So, this function
+/// will return a pointer to the llvm::Value corresponding to the
+/// block argument for the mapped descriptor.
+static llvm::Value *
+findHostAssociatedValue(Value privateVar, omp::TargetOp targetOp,
+                        llvm::DenseMap<Value, int> &mappedPrivateVars,
+                        llvm::IRBuilderBase &builder,
+                        LLVM::ModuleTranslation &moduleTranslation) {
+  if (mappedPrivateVars.contains(privateVar)) {
+    int blockArgIndex = mappedPrivateVars[privateVar];
+    Value blockArg = targetOp.getRegion().getArgument(blockArgIndex);
+    mlir::Type privVarType = privateVar.getType();
+    mlir::Type blockArgType = blockArg.getType();
+    assert(isa<LLVM::LLVMPointerType>(blockArgType) &&
+           "A block argument corresponding to a mapped var should have "
+           "!llvm.ptr type");
+
+    if (privVarType == blockArg.getType()) {
+      llvm::Value *v = moduleTranslation.lookupValue(blockArg);
+      return v;
+    }
----------------
Dinistro wrote:

```suggestion
    if (privVarType == blockArg.getType())
      return moduleTranslation.lookupValue(blockArg);
```

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