Generate debug info for by-value struct args even if they are not used.

radar://problem/13865940

llvm-svn: 182062

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 2ded723ca0f..7072def6285 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -6753,9 +6753,15 @@ void SelectionDAGISel::LowerArguments(const Function &F) {
 
     // If this argument is unused then remember its value. It is used to generate
     // debugging information.
-    if (I->use_empty() && NumValues)
+    if (I->use_empty() && NumValues) {
       SDB->setUnusedArgValue(I, InVals[i]);
 
+      // Also remember any frame index for use in FastISel.
+      if (FrameIndexSDNode *FI =
+          dyn_cast<FrameIndexSDNode>(InVals[i].getNode()))
+        FuncInfo->setArgumentFrameIndex(I, FI->getIndex());
+    }
+
     for (unsigned Val = 0; Val != NumValues; ++Val) {
       EVT VT = ValueVTs[Val];
       MVT PartVT = TLI.getRegisterType(*CurDAG->getContext(), VT);