[llvm-branch-commits] [flang] [mlir] [flang][OpenMP] Lower target in_reduction for host fallback (PR #199967)

[Sairudra More via llvm-branch-commits]

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@@ -8334,6 +8393,36 @@ convertOmpTarget(Operation &opInst, llvm::IRBuilderBase &builder,
             targetOp.getPrivateNeedsBarrier(), &mappedPrivateVars)))
       return llvm::make_error<PreviouslyReportedError>();
 
+    // Map in_reduction block arguments to the per-task private storage
+    // returned by __kmpc_task_reduction_get_th_data. The lookup must run
+    // inside the target task body so the gtid corresponds to the executing
+    // thread. The descriptor argument is NULL: the runtime walks enclosing
+    // taskgroups to locate the matching task_reduction registration for
+    // `origPtr`. Mirrors the in_reduction handling on omp.taskloop.context.
+    ArrayRef<BlockArgument> inRedBlockArgs = argIface.getInReductionBlockArgs();
+    if (!inRedBlockArgs.empty()) {
+      llvm::OpenMPIRBuilder &ompB = *moduleTranslation.getOpenMPBuilder();
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Saieiei wrote:

Done!
latest code uses the existing `ompBuilder`.

https://github.com/llvm/llvm-project/pull/199967