[llvm] [StatepointLowering] Handle struct return through stack (PR #157251)

[Matt Arsenault via llvm-commits]

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@@ -337,13 +337,17 @@ static std::pair<SDValue, SDNode *> lowerCallFromStatepointLoweringInfo(
   //
   // get_return_value can either be a sequence of CopyFromReg instructions
   // to grab the return value from the return register(s), or it can be a LOAD
-  // to load a value returned by reference via a stack slot.
+  // to load a value returned by reference via a stack slot, or it can be a
+  // struct returned by value through stack.
 
   if (CallEnd->getOpcode() == ISD::EH_LABEL)
     CallEnd = CallEnd->getOperand(0).getNode();
 
-  bool HasDef = !SI.CLI.RetTy->isVoidTy();
+  bool HasDef = !SI.CLI.RetTy->isVoidTy() || !SI.CLI.OutVals.empty();
   if (HasDef) {
+    if (CallEnd->getOpcode() == ISD::TokenFactor)
+      CallEnd = CallEnd->getOperand(0).getNode();
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arsenm wrote:

This is making an assumption about the ordering of the TokenFactor inputs, don't do that? You should have an explicit reference to the call end direct from lowerInvokable?

https://github.com/llvm/llvm-project/pull/157251