diff --git a/include/llvm/CodeGen/FunctionLoweringInfo.h b/include/llvm/CodeGen/FunctionLoweringInfo.h
index 26214a6..09dac85 100644
--- a/include/llvm/CodeGen/FunctionLoweringInfo.h
+++ b/include/llvm/CodeGen/FunctionLoweringInfo.h
@@ -199,12 +199,12 @@
     LiveOutRegInfo[Reg].IsValid = false;
   }
 
-  /// setByValArgumentFrameIndex - Record frame index for the byval
+  /// setArgumentFrameIndex - Record frame index for the byval
   /// argument.
-  void setByValArgumentFrameIndex(const Argument *A, int FI);
+  void setArgumentFrameIndex(const Argument *A, int FI);
   
-  /// getByValArgumentFrameIndex - Get frame index for the byval argument.
-  int getByValArgumentFrameIndex(const Argument *A);
+  /// getArgumentFrameIndex - Get frame index for the byval argument.
+  int getArgumentFrameIndex(const Argument *A);
 
 private:
   /// LiveOutRegInfo - Information about live out vregs.
diff --git a/lib/CodeGen/SelectionDAG/FastISel.cpp b/lib/CodeGen/SelectionDAG/FastISel.cpp
index 226edc6..fbd0c62 100644
--- a/lib/CodeGen/SelectionDAG/FastISel.cpp
+++ b/lib/CodeGen/SelectionDAG/FastISel.cpp
@@ -531,13 +531,10 @@
     unsigned Reg = 0;
     unsigned Offset = 0;
     if (const Argument *Arg = dyn_cast<Argument>(Address)) {
-      if (Arg->hasByValAttr()) {
-        // Byval arguments' frame index is recorded during argument lowering.
-        // Use this info directly.
-        Offset = FuncInfo.getByValArgumentFrameIndex(Arg);
-        if (Offset)
-          Reg = TRI.getFrameRegister(*FuncInfo.MF);
-      }
+      // Some arguments' frame index is recorded during argument lowering.
+      Offset = FuncInfo.getArgumentFrameIndex(Arg);
+      if (Offset)
+	Reg = TRI.getFrameRegister(*FuncInfo.MF);
     }
     if (!Reg)
       Reg = getRegForValue(Address);
diff --git a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
index 10b251d..b052740 100644
--- a/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
+++ b/lib/CodeGen/SelectionDAG/FunctionLoweringInfo.cpp
@@ -351,20 +351,18 @@
   }
 }
 
-/// setByValArgumentFrameIndex - Record frame index for the byval
+/// setArgumentFrameIndex - Record frame index for the byval
 /// argument. This overrides previous frame index entry for this argument,
 /// if any.
-void FunctionLoweringInfo::setByValArgumentFrameIndex(const Argument *A,
+void FunctionLoweringInfo::setArgumentFrameIndex(const Argument *A,
                                                       int FI) {
-  assert (A->hasByValAttr() && "Argument does not have byval attribute!");
   ByValArgFrameIndexMap[A] = FI;
 }
 
-/// getByValArgumentFrameIndex - Get frame index for the byval argument.
+/// getArgumentFrameIndex - Get frame index for the byval argument.
 /// If the argument does not have any assigned frame index then 0 is
 /// returned.
-int FunctionLoweringInfo::getByValArgumentFrameIndex(const Argument *A) {
-  assert (A->hasByValAttr() && "Argument does not have byval attribute!");
+int FunctionLoweringInfo::getArgumentFrameIndex(const Argument *A) {
   DenseMap<const Argument *, int>::iterator I =
     ByValArgFrameIndexMap.find(A);
   if (I != ByValArgFrameIndexMap.end())
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 1337754..9ba1fbb 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4394,17 +4394,12 @@
     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 @@
     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.
diff --git a/test/CodeGen/ARM/debug-info-arg.ll b/test/CodeGen/ARM/debug-info-arg.ll
new file mode 100644
index 0000000..b0270f9
--- /dev/null
+++ b/test/CodeGen/ARM/debug-info-arg.ll
@@ -0,0 +1,65 @@
+; RUN: llc < %s | FileCheck %s
+; Test to check argument y's debug info uses FI
+; Radar 10048772
+target datalayout = "e-p:32:32:32-i1:8:32-i8:8:32-i16:16:32-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:32:64-v128:32:128-a0:0:32-n32"
+target triple = "thumbv7-apple-macosx10.7.0"
+
+%struct.tag_s = type { i32, i32, i32 }
+
+define void @foo(%struct.tag_s* nocapture %this, %struct.tag_s* %c, i64 %x, i64 %y, %struct.tag_s* nocapture %ptr1, %struct.tag_s* nocapture %ptr2) nounwind ssp {
+  tail call void @llvm.dbg.value(metadata !{%struct.tag_s* %this}, i64 0, metadata !5), !dbg !20
+  tail call void @llvm.dbg.value(metadata !{%struct.tag_s* %c}, i64 0, metadata !13), !dbg !21
+  tail call void @llvm.dbg.value(metadata !{i64 %x}, i64 0, metadata !14), !dbg !22
+  tail call void @llvm.dbg.value(metadata !{i64 %y}, i64 0, metadata !17), !dbg !23
+;CHECK:	@DEBUG_VALUE: foo:y <- R7+4294967295
+  tail call void @llvm.dbg.value(metadata !{%struct.tag_s* %ptr1}, i64 0, metadata !18), !dbg !24
+  tail call void @llvm.dbg.value(metadata !{%struct.tag_s* %ptr2}, i64 0, metadata !19), !dbg !25
+  %1 = icmp eq %struct.tag_s* %c, null, !dbg !26
+  br i1 %1, label %3, label %2, !dbg !26
+
+; <label>:2                                       ; preds = %0
+  tail call void @foobar(i64 %x, i64 %y) nounwind, !dbg !28
+  br label %3, !dbg !28
+
+; <label>:3                                       ; preds = %0, %2
+  ret void, !dbg !29
+}
+
+declare void @foobar(i64, i64)
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+
+!llvm.dbg.cu = !{!0}
+!llvm.dbg.sp = !{!1}
+!llvm.dbg.lv.foo = !{!5, !13, !14, !17, !18, !19}
+
+!0 = metadata !{i32 589841, i32 0, i32 12, metadata !"one.c", metadata !"/Volumes/Athwagate/R10048772", metadata !"Apple clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM 3.0svn)", i1 true, i1 true, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!1 = metadata !{i32 589870, i32 0, metadata !2, metadata !"foo", metadata !"foo", metadata !"", metadata !2, i32 11, metadata !3, i1 false, i1 true, i32 0, i32 0, i32 0, i32 256, i1 true, void (%struct.tag_s*, %struct.tag_s*, i64, i64, %struct.tag_s*, %struct.tag_s*)* @foo, null, null} ; [ DW_TAG_subprogram ]
+!2 = metadata !{i32 589865, metadata !"one.c", metadata !"/Volumes/Athwagate/R10048772", metadata !0} ; [ DW_TAG_file_type ]
+!3 = metadata !{i32 589845, metadata !2, metadata !"", metadata !2, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !4, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!4 = metadata !{null}
+!5 = metadata !{i32 590081, metadata !1, metadata !"this", metadata !2, i32 16777227, metadata !6, i32 0} ; [ DW_TAG_arg_variable ]
+!6 = metadata !{i32 589839, metadata !0, metadata !"", null, i32 0, i64 32, i64 32, i64 0, i32 0, metadata !7} ; [ DW_TAG_pointer_type ]
+!7 = metadata !{i32 589843, metadata !0, metadata !"tag_s", metadata !2, i32 5, i64 96, i64 32, i32 0, i32 0, i32 0, metadata !8, i32 0, i32 0} ; [ DW_TAG_structure_type ]
+!8 = metadata !{metadata !9, metadata !11, metadata !12}
+!9 = metadata !{i32 589837, metadata !7, metadata !"x", metadata !2, i32 6, i64 32, i64 32, i64 0, i32 0, metadata !10} ; [ DW_TAG_member ]
+!10 = metadata !{i32 589860, metadata !0, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!11 = metadata !{i32 589837, metadata !7, metadata !"y", metadata !2, i32 7, i64 32, i64 32, i64 32, i32 0, metadata !10} ; [ DW_TAG_member ]
+!12 = metadata !{i32 589837, metadata !7, metadata !"z", metadata !2, i32 8, i64 32, i64 32, i64 64, i32 0, metadata !10} ; [ DW_TAG_member ]
+!13 = metadata !{i32 590081, metadata !1, metadata !"c", metadata !2, i32 33554443, metadata !6, i32 0} ; [ DW_TAG_arg_variable ]
+!14 = metadata !{i32 590081, metadata !1, metadata !"x", metadata !2, i32 50331659, metadata !15, i32 0} ; [ DW_TAG_arg_variable ]
+!15 = metadata !{i32 589846, metadata !0, metadata !"UInt64", metadata !2, i32 1, i64 0, i64 0, i64 0, i32 0, metadata !16} ; [ DW_TAG_typedef ]
+!16 = metadata !{i32 589860, metadata !0, metadata !"long long unsigned int", null, i32 0, i64 64, i64 32, i64 0, i32 0, i32 7} ; [ DW_TAG_base_type ]
+!17 = metadata !{i32 590081, metadata !1, metadata !"y", metadata !2, i32 67108875, metadata !15, i32 0} ; [ DW_TAG_arg_variable ]
+!18 = metadata !{i32 590081, metadata !1, metadata !"ptr1", metadata !2, i32 83886091, metadata !6, i32 0} ; [ DW_TAG_arg_variable ]
+!19 = metadata !{i32 590081, metadata !1, metadata !"ptr2", metadata !2, i32 100663307, metadata !6, i32 0} ; [ DW_TAG_arg_variable ]
+!20 = metadata !{i32 11, i32 24, metadata !1, null}
+!21 = metadata !{i32 11, i32 44, metadata !1, null}
+!22 = metadata !{i32 11, i32 54, metadata !1, null}
+!23 = metadata !{i32 11, i32 64, metadata !1, null}
+!24 = metadata !{i32 11, i32 81, metadata !1, null}
+!25 = metadata !{i32 11, i32 101, metadata !1, null}
+!26 = metadata !{i32 12, i32 3, metadata !27, null}
+!27 = metadata !{i32 589835, metadata !1, i32 11, i32 107, metadata !2, i32 0} ; [ DW_TAG_lexical_block ]
+!28 = metadata !{i32 13, i32 5, metadata !27, null}
+!29 = metadata !{i32 14, i32 1, metadata !27, null}