Directly point debug info to the stack slot of the arugment, instead of trying to keep track of vreg in which it the arugment is copied. The LiveDebugVariable can keep track of variable's ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139330 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 17 insertions, 15 deletions

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 1337754ee6..9ba1fbb7ab 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4394,17 +4394,12 @@ 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.
-    Reg = TRI->getFrameRegister(MF);
-    Offset = FuncInfo.getByValArgumentFrameIndex(Arg);
-    // If byval argument ofset is not recorded then ignore this.
-    if (!Offset)
-      Reg = 0;
-  }
+  // Some arguments' frame index is recorded during argument lowering.
+  Offset = FuncInfo.getArgumentFrameIndex(Arg);
+  if (Offset)
+      Reg = TRI->getFrameRegister(MF);
 
-  if (N.getNode()) {
+  if (!Reg && N.getNode()) {
     if (N.getOpcode() == ISD::CopyFromReg)
       Reg = cast<RegisterSDNode>(N.getOperand(1))->getReg();
     else
@@ -6733,15 +6728,22 @@ void SelectionDAGISel::LowerArguments(const BasicBlock *LLVMBB) {
     if (ArgValues.empty())
       continue;
 
-    // Note down frame index for byval arguments.
-    if (I->hasByValAttr())
-      if (FrameIndexSDNode *FI =
-          dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode()))
-        FuncInfo->setByValArgumentFrameIndex(I, FI->getIndex());
+    // Note down frame index.
+    if (FrameIndexSDNode *FI =
+	dyn_cast<FrameIndexSDNode>(ArgValues[0].getNode()))
+      FuncInfo->setArgumentFrameIndex(I, FI->getIndex());
 
     SDValue Res = DAG.getMergeValues(&ArgValues[0], NumValues,
                                      SDB->getCurDebugLoc());
+
     SDB->setValue(I, Res);
+    if (!EnableFastISel && Res.getOpcode() == ISD::BUILD_PAIR) {
+      if (LoadSDNode *LNode = 
+          dyn_cast<LoadSDNode>(Res.getOperand(0).getNode()))
+        if (FrameIndexSDNode *FI =
+            dyn_cast<FrameIndexSDNode>(LNode->getBasePtr().getNode()))
+        FuncInfo->setArgumentFrameIndex(I, FI->getIndex());
+    }
 
     // If this argument is live outside of the entry block, insert a copy from
     // wherever we got it to the vreg that other BB's will reference it as.