Remember byval argument's frame index during argument lowering and use this info to emit debug info.

Fixes Radar 8367011.

llvm-svn: 112623

1 files changed, 16 insertions, 1 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index b70bfeaba5a..0a330213a16 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -3917,7 +3917,8 @@ bool
 SelectionDAGBuilder::EmitFuncArgumentDbgValue(const Value *V, MDNode *Variable,
                                               int64_t Offset, 
                                               const SDValue &N) {
-  if (!isa<Argument>(V))
+  const Argument *Arg = dyn_cast<Argument>(V);
+  if (!Arg)
     return false;
 
   MachineFunction &MF = DAG.getMachineFunction();
@@ -3931,6 +3932,14 @@ SelectionDAGBuilder::EmitFuncArgumentDbgValue(const Value *V, MDNode *Variable,
     return false;
 
   unsigned Reg = 0;
+  if (Arg->hasByValAttr()) {
+    // Byval arguments' frame index is recorded during argument lowering.
+    // Use this info directly.
+    const TargetRegisterInfo *TRI = DAG.getTarget().getRegisterInfo();
+    Reg = TRI->getFrameRegister(MF);
+    Offset = FuncInfo.getByValArgumentFrameIndex(Arg);
+  }
+
   if (N.getNode() && N.getOpcode() == ISD::CopyFromReg) {
     Reg = cast<RegisterSDNode>(N.getOperand(1))->getReg();
     if (Reg && TargetRegisterInfo::isVirtualRegister(Reg)) {
@@ -6131,6 +6140,12 @@ void SelectionDAGISel::LowerArguments(const BasicBlock *LLVMBB) {
       i += NumParts;
     }
 
+    // Note down frame index for byval arguments.
+    if (I->hasByValAttr() && !ArgValues.empty())
+      if (FrameIndexSDNode *FI = 
+          dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode()))
+        FuncInfo->setByValArgumentFrameIndex(I, FI->getIndex());
+
     if (!I->use_empty()) {
       SDValue Res;
       if (!ArgValues.empty())