[Mlir-commits] [llvm] [mlir] [OMPIRBuilder] - Make offloading input data persist for deferred target tasks (PR #133499)

[Sergio Afonso]

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@@ -7051,9 +7051,25 @@ static Expected<Function *> createOutlinedFunction(
 /// void @.omp_target_task_proxy_func(i32 %thread.id, ptr %task)
 /// This function is called from emitTargetTask once the
 /// code to launch the target kernel has been outlined already.
-static Function *emitTargetTaskProxyFunction(OpenMPIRBuilder &OMPBuilder,
-                                             IRBuilderBase &Builder,
-                                             CallInst *StaleCI) {
+static Function *emitTargetTaskProxyFunction(
+    OpenMPIRBuilder &OMPBuilder, IRBuilderBase &Builder, CallInst *StaleCI,
+    StructType *PrivatesTy, StructType *TaskWithPrivatesTy,
+    const size_t NumOffloadingArrays, const int SharedArgsOperandNo) {
+
+  // NumOffloadingArrays is the number of offloading arrays that we need to copy
+  // into the task structure so that the deferred target task can access this
+  // data even after the stack frame of the generating task has been rolled
+  // back. Offloading arrays contain base pointers, pointers, sizes etc
+  // of the data that the target kernel will access. In other words, the
+  // arrays of pointers held by OpenMPIRBuilder::TargetDataRTArgs
+  // The number of arrays and the size of each array depends on the specifics of
+  // the target call. These arrays are copied into a struct whose type is
+  // PrivatesTy. So, if NumOffloadingArrays is non-zero, PrivatesTy better
+  // not be nullptr
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skatrak wrote:

Nit: It seems like a big chunk of this comment can be moved above to the function documentation for these arguments.

https://github.com/llvm/llvm-project/pull/133499