diff --git a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
index 0ebd94a0126..db03ed954ec 100644
--- a/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
+++ b/lib/CodeGen/AsmPrinter/DwarfDebug.cpp
@@ -2257,15 +2257,6 @@ DwarfDebug::collectVariableInfoFromMMITable(const MachineFunction * MF,
   }
 }
 
-/// isDbgValueInUndefinedReg - Return true if debug value, encoded by
-/// DBG_VALUE instruction, is in undefined reg.
-static bool isDbgValueInUndefinedReg(const MachineInstr *MI) {
-  assert (MI->isDebugValue() && "Invalid DBG_VALUE machine instruction!");
-  if (MI->getOperand(0).isReg() && !MI->getOperand(0).getReg())
-    return true;
-  return false;
-}
-
 /// isDbgValueInDefinedReg - Return true if debug value, encoded by
 /// DBG_VALUE instruction, is in a defined reg.
 static bool isDbgValueInDefinedReg(const MachineInstr *MI) {
@@ -2290,7 +2281,7 @@ DwarfDebug::collectVariableInfo(const MachineFunction *MF,
     for (MachineBasicBlock::const_iterator II = I->begin(), IE = I->end();
          II != IE; ++II) {
       const MachineInstr *MInsn = II;
-      if (!MInsn->isDebugValue() || isDbgValueInUndefinedReg(MInsn))
+      if (!MInsn->isDebugValue())
         continue;
       DbgValues.push_back(MInsn);
     }
@@ -2312,19 +2303,18 @@ DwarfDebug::collectVariableInfo(const MachineFunction *MF,
            ME = DbgValues.end(); MI != ME; ++MI) {
       const MDNode *Var =
         (*MI)->getOperand((*MI)->getNumOperands()-1).getMetadata();
-      if (Var == DV && isDbgValueInDefinedReg(*MI) &&
+      if (Var == DV && 
           !PrevMI->isIdenticalTo(*MI))
         MultipleValues.push_back(*MI);
       PrevMI = *MI;
     }
 
-    DbgScope *Scope = findDbgScope(MInsn);
-    bool CurFnArg = false;
+    DbgScope *Scope = NULL;
     if (DV.getTag() == dwarf::DW_TAG_arg_variable &&
         DISubprogram(DV.getContext()).describes(MF->getFunction()))
-      CurFnArg = true;
-    if (!Scope && CurFnArg)
       Scope = CurrentFnDbgScope;
+    else
+      Scope = findDbgScope(MInsn);
     // If variable scope is not found then skip this variable.
     if (!Scope)
       continue;
diff --git a/lib/CodeGen/LiveDebugVariables.cpp b/lib/CodeGen/LiveDebugVariables.cpp
index baedfc3efb5..2b6a54eab5a 100644
--- a/lib/CodeGen/LiveDebugVariables.cpp
+++ b/lib/CodeGen/LiveDebugVariables.cpp
@@ -39,10 +39,6 @@
 
 using namespace llvm;
 
-static cl::opt<bool>
-EnableLDV("live-debug-variables",
-          cl::desc("Enable the live debug variables pass"), cl::Hidden);
-
 char LiveDebugVariables::ID = 0;
 
 INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
@@ -622,8 +618,6 @@ bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
 }
 
 bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
-  if (!EnableLDV)
-    return false;
   if (!pImpl)
     pImpl = new LDVImpl(this);
   return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
diff --git a/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll b/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll
index 13f72a99d2b..60171eb6297 100644
--- a/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll
+++ b/test/CodeGen/X86/2010-05-26-DotDebugLoc.ll
@@ -61,6 +61,6 @@ declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
 ; CHECK-NEXT: .short  1
 ; CHECK-NEXT: .byte   85
 ; CHECK-NEXT: .quad   Ltmp3
-; CHECK-NEXT: .quad   Lfunc_end
+; CHECK-NEXT: .quad   Ltmp6
 ; CHECK-NEXT: .short  1
 ; CHECK-NEXT: .byte   83
diff --git a/test/CodeGen/X86/2010-05-28-Crash.ll b/test/CodeGen/X86/2010-05-28-Crash.ll
index 80643d0792a..b504badc2e1 100644
--- a/test/CodeGen/X86/2010-05-28-Crash.ll
+++ b/test/CodeGen/X86/2010-05-28-Crash.ll
@@ -39,6 +39,5 @@ entry:
 !13 = metadata !{i32 7, i32 0, metadata !14, null}
 !14 = metadata !{i32 524299, metadata !8, i32 6, i32 0} ; [ DW_TAG_lexical_block ]
 
-;CHECK:	        DEBUG_VALUE: bar:x <- EBX+0
-;CHECK-NEXT:Ltmp
+;CHECK:Ltmp8
 ;CHECK-NEXT:	DEBUG_VALUE: foo:y <- 1+0
diff --git a/test/CodeGen/X86/dbg-value-range.ll b/test/CodeGen/X86/dbg-value-range.ll
new file mode 100644
index 00000000000..4d615d7c82d
--- /dev/null
+++ b/test/CodeGen/X86/dbg-value-range.ll
@@ -0,0 +1,56 @@
+; RUN: llc -mtriple=x86_64-apple-darwin < %s | FileCheck %s
+
+%struct.a = type { i32 }
+
+define i32 @bar(%struct.a* nocapture %b) nounwind ssp {
+entry:
+  tail call void @llvm.dbg.value(metadata !{%struct.a* %b}, i64 0, metadata !6), !dbg !13
+  %tmp1 = getelementptr inbounds %struct.a* %b, i64 0, i32 0, !dbg !14
+  %tmp2 = load i32* %tmp1, align 4, !dbg !14, !tbaa !15
+  tail call void @llvm.dbg.value(metadata !{i32 %tmp2}, i64 0, metadata !11), !dbg !14
+  %call = tail call i32 (...)* @foo(i32 %tmp2) nounwind , !dbg !18
+  %add = add nsw i32 %tmp2, 1, !dbg !19
+  ret i32 %add, !dbg !19
+}
+
+declare i32 @foo(...) 
+
+declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+
+!llvm.dbg.sp = !{!0}
+!llvm.dbg.lv.bar = !{!6, !11}
+
+!0 = metadata !{i32 589870, i32 0, metadata !1, metadata !"bar", metadata !"bar", metadata !"", metadata !1, i32 5, metadata !3, i1 false, i1 true, i32 0, i32 0, i32 0, i32 256, i1 true, i32 (%struct.a*)* @bar} ; [ DW_TAG_subprogram ]
+!1 = metadata !{i32 589865, metadata !"bar.c", metadata !"/private/tmp", metadata !2} ; [ DW_TAG_file_type ]
+!2 = metadata !{i32 589841, i32 0, i32 12, metadata !"bar.c", metadata !"/private/tmp", metadata !"clang version 2.9 (trunk 122997)", i1 true, i1 true, metadata !"", i32 0} ; [ DW_TAG_compile_unit ]
+!3 = metadata !{i32 589845, metadata !1, metadata !"", metadata !1, i32 0, i64 0, i64 0, i32 0, i32 0, i32 0, metadata !4, i32 0, i32 0} ; [ DW_TAG_subroutine_type ]
+!4 = metadata !{metadata !5}
+!5 = metadata !{i32 589860, metadata !2, metadata !"int", null, i32 0, i64 32, i64 32, i64 0, i32 0, i32 5} ; [ DW_TAG_base_type ]
+!6 = metadata !{i32 590081, metadata !0, metadata !"b", metadata !1, i32 5, metadata !7, i32 0} ; [ DW_TAG_arg_variable ]
+!7 = metadata !{i32 589839, metadata !2, metadata !"", null, i32 0, i64 64, i64 64, i64 0, i32 0, metadata !8} ; [ DW_TAG_pointer_type ]
+!8 = metadata !{i32 589843, metadata !2, metadata !"a", metadata !1, i32 1, i64 32, i64 32, i32 0, i32 0, i32 0, metadata !9, i32 0, i32 0} ; [ DW_TAG_structure_type ]
+!9 = metadata !{metadata !10}
+!10 = metadata !{i32 589837, metadata !1, metadata !"c", metadata !1, i32 2, i64 32, i64 32, i64 0, i32 0, metadata !5} ; [ DW_TAG_member ]
+!11 = metadata !{i32 590080, metadata !12, metadata !"x", metadata !1, i32 6, metadata !5, i32 0} ; [ DW_TAG_auto_variable ]
+!12 = metadata !{i32 589835, metadata !0, i32 5, i32 22, metadata !1, i32 0} ; [ DW_TAG_lexical_block ]
+!13 = metadata !{i32 5, i32 19, metadata !0, null}
+!14 = metadata !{i32 6, i32 14, metadata !12, null}
+!15 = metadata !{metadata !"int", metadata !16}
+!16 = metadata !{metadata !"omnipotent char", metadata !17}
+!17 = metadata !{metadata !"Simple C/C++ TBAA", null}
+!18 = metadata !{i32 7, i32 2, metadata !12, null}
+!19 = metadata !{i32 8, i32 2, metadata !12, null}
+
+; check that variable bar:b value range is appropriately trucated in debug info. Here Ltmp5 is end of
+; location range.
+
+;CHECK:Ltmp5
+;CHECK-NEXT: DEBUG_VALUE: bar:b <- undef
+
+;CHECK:Ldebug_loc0:
+;CHECK-NEXT:	.quad	Ltmp
+;CHECK-NEXT:	.quad	Ltmp5
+;CHECK-NEXT:	.short	1
+;CHECK-NEXT:	.byte	85
+;CHECK-NEXT:	.quad	0
+;CHECK-NEXT:	.quad	0