diff --git a/include/llvm/Analysis/DIBuilder.h b/include/llvm/Analysis/DIBuilder.h
index 417dbc4e802..32a17e4f096 100644
--- a/include/llvm/Analysis/DIBuilder.h
+++ b/include/llvm/Analysis/DIBuilder.h
@@ -326,11 +326,14 @@ namespace llvm {
     /// @param AlwaysPreserve Boolean. Set to true if debug info for this
     ///                       variable should be preserved in optimized build.
     /// @param Flags          Flags, e.g. artificial variable.
+    /// @param ArgNo       If this variable is an arugment then this argument's
+    ///                    number. 1 indicates 1st argument.
     DIVariable createLocalVariable(unsigned Tag, DIDescriptor Scope,
                                    StringRef Name,
                                    DIFile File, unsigned LineNo,
                                    DIType Ty, bool AlwaysPreserve = false,
-                                   unsigned Flags = 0);
+                                   unsigned Flags = 0,
+                                   unsigned ArgNo = 0);
 
 
     /// createComplexVariable - Create a new descriptor for the specified
@@ -344,10 +347,12 @@ namespace llvm {
     /// @param Ty          Variable Type
     /// @param Addr        A pointer to a vector of complex address operations.
     /// @param NumAddr     Num of address operations in the vector.
+    /// @param ArgNo       If this variable is an arugment then this argument's
+    ///                    number. 1 indicates 1st argument.
     DIVariable createComplexVariable(unsigned Tag, DIDescriptor Scope,
                                      StringRef Name, DIFile F, unsigned LineNo,
                                      DIType Ty, Value *const *Addr,
-                                     unsigned NumAddr);
+                                     unsigned NumAddr, unsigned ArgNo = 0);
 
     /// createFunction - Create a new descriptor for the specified subprogram.
     /// See comments in DISubprogram for descriptions of these fields.
diff --git a/include/llvm/Analysis/DebugInfo.h b/include/llvm/Analysis/DebugInfo.h
index aa69088b425..e75b74ffed3 100644
--- a/include/llvm/Analysis/DebugInfo.h
+++ b/include/llvm/Analysis/DebugInfo.h
@@ -564,7 +564,13 @@ namespace llvm {
       DIFile F = getFieldAs<DIFile>(3); 
       return F.getCompileUnit();
     }
-    unsigned getLineNumber() const      { return getUnsignedField(4); }
+    unsigned getLineNumber() const      { 
+      return (getUnsignedField(4) << 8) >> 8; 
+    }
+    unsigned getArgNumber() const       {
+      unsigned L = getUnsignedField(4); 
+      return L >> 24;
+    }
     DIType getType() const              { return getFieldAs<DIType>(5); }
     
     /// isArtificial - Return true if this variable is marked as "artificial".
diff --git a/lib/Analysis/DIBuilder.cpp b/lib/Analysis/DIBuilder.cpp
index 590a9c17a8f..766624f87ce 100644
--- a/lib/Analysis/DIBuilder.cpp
+++ b/lib/Analysis/DIBuilder.cpp
@@ -586,13 +586,14 @@ createStaticVariable(DIDescriptor Context, StringRef Name,
 DIVariable DIBuilder::createLocalVariable(unsigned Tag, DIDescriptor Scope,
                                           StringRef Name, DIFile File,
                                           unsigned LineNo, DIType Ty, 
-                                          bool AlwaysPreserve, unsigned Flags) {
+                                          bool AlwaysPreserve, unsigned Flags,
+                                          unsigned ArgNo) {
   Value *Elts[] = {
     GetTagConstant(VMContext, Tag),
     Scope,
     MDString::get(VMContext, Name),
     File,
-    ConstantInt::get(Type::getInt32Ty(VMContext), LineNo),
+    ConstantInt::get(Type::getInt32Ty(VMContext), (LineNo | (ArgNo << 24))),
     Ty,
     ConstantInt::get(Type::getInt32Ty(VMContext), Flags)
   };
@@ -620,13 +621,13 @@ DIVariable DIBuilder::createComplexVariable(unsigned Tag, DIDescriptor Scope,
                                             StringRef Name, DIFile F,
                                             unsigned LineNo,
                                             DIType Ty, Value *const *Addr,
-                                            unsigned NumAddr) {
+                                            unsigned NumAddr, unsigned ArgNo) {
   SmallVector<Value *, 15> Elts;
   Elts.push_back(GetTagConstant(VMContext, Tag));
   Elts.push_back(Scope);
   Elts.push_back(MDString::get(VMContext, Name));
   Elts.push_back(F);
-  Elts.push_back(ConstantInt::get(Type::getInt32Ty(VMContext), LineNo));
+  Elts.push_back(ConstantInt::get(Type::getInt32Ty(VMContext), (LineNo | (ArgNo << 24))));
   Elts.push_back(Ty);
   Elts.append(Addr, Addr+NumAddr);
 
@@ -642,7 +643,6 @@ DISubprogram DIBuilder::createFunction(DIDescriptor Context,
                                        bool isLocalToUnit, bool isDefinition,
                                        unsigned Flags, bool isOptimized,
                                        Function *Fn) {
-
   Value *Elts[] = {
     GetTagConstant(VMContext, dwarf::DW_TAG_subprogram),
     llvm::Constant::getNullValue(Type::getInt32Ty(VMContext)),