[Mlir-commits] [llvm] [mlir] [mlir][OpenMP] - Implement lowering from MLIR to LLVMIR for `private` clause on `target` constructs (PR #105471)

[Tom Eccles]

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@@ -3241,12 +3242,140 @@ convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
   DataLayout dl = DataLayout(opInst.getParentOfType<ModuleOp>());
   SmallVector<Value> mapVars = targetOp.getMapVars();
   llvm::Function *llvmOutlinedFn = nullptr;
-
   // TODO: It can also be false if a compile-time constant `false` IF clause is
   // specified.
   bool isOffloadEntry =
       isTargetDevice || !ompBuilder->Config.TargetTriples.empty();
 
+  if (!targetOp.getPrivateVars().empty()) {
+    OperandRange privateVars = targetOp.getPrivateVars();
+    std::optional<mlir::ArrayAttr> privateSyms = targetOp.getPrivateSyms();
+    auto &targetRegion = opInst.getRegion(0);
+    auto &firstTargetBlock = targetRegion.front();
+    auto *regionArgsStart = firstTargetBlock.getArguments().begin();
+    auto *privArgsStart = regionArgsStart + targetOp.getMapVars().size();
+    auto *privArgsEnd = privArgsStart + targetOp.getPrivateVars().size();
+    BitVector blockArgsBV(firstTargetBlock.getNumArguments(), false);
+    omp::PrivateClauseOps newPrivateClauses;
+    MutableArrayRef argSubRangePrivates(privArgsStart, privArgsEnd);
+    for (auto [privVar, privatizerNameAttr, blockArg] :
+         llvm::zip_equal(privateVars, *privateSyms, argSubRangePrivates)) {
+
+      SymbolRefAttr privSym = llvm::cast<SymbolRefAttr>(privatizerNameAttr);
+
+      // 1. Look up the privatizer in the symbol table
+      MLIRContext &context = moduleTranslation.getContext();
+      mlir::IRRewriter rewriter(&context);
+      omp::PrivateClauseOp privatizer =
+          SymbolTable::lookupNearestSymbolFrom<omp::PrivateClauseOp>(&opInst,
+                                                                     privSym);
+      // Handle only private for now. Also, not handling allocatables yet.
+      if (privatizer.getDataSharingType() !=
+              omp::DataSharingClauseType::Private ||
+          !privatizer.getDeallocRegion().empty()) {
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tblah wrote:

Otherwise could you return to indicate failure?

https://github.com/llvm/llvm-project/pull/105471