diff --git a/lib/CodeGen/CGExpr.cpp b/lib/CodeGen/CGExpr.cpp
index 309f38e..332d47c 100644
--- a/lib/CodeGen/CGExpr.cpp
+++ b/lib/CodeGen/CGExpr.cpp
@@ -490,8 +490,17 @@
     // load of a __strong object.
     llvm::Value *LvalueDst = Dst.getAddress();
     llvm::Value *src = Src.getScalarVal();
-    if (Dst.isObjCIvar())
-      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, LvalueDst);
+    if (Dst.isObjCIvar()) {
+      assert(Dst.getBaseIvarExp() && "BaseIvarExp is NULL");
+      const llvm::Type *ResultType = ConvertType(getContext().LongTy);
+      llvm::Value *RHS = EmitScalarExpr(Dst.getBaseIvarExp());
+      RHS = Builder.CreatePtrToInt(RHS, ResultType, "sub.ptr.rhs.cast");
+      llvm::Value *LHS = 
+        Builder.CreatePtrToInt(LvalueDst, ResultType, "sub.ptr.lhs.cast");
+      llvm::Value *BytesBetween = Builder.CreateSub(LHS, RHS, "ivar.offset");
+      CGM.getObjCRuntime().EmitObjCIvarAssign(*this, src, LvalueDst,
+                                              BytesBetween);
+    }
     else if (Dst.isGlobalObjCRef())
       CGM.getObjCRuntime().EmitObjCGlobalAssign(*this, src, LvalueDst);
     else
@@ -694,6 +703,8 @@
   
   if (isa<ObjCIvarRefExpr>(E)) {
     LV.SetObjCIvar(LV, true);
+    ObjCIvarRefExpr *Exp = cast<ObjCIvarRefExpr>(const_cast<Expr*>(E));
+    LV.setBaseIvarExp(Exp->getBase());
     LV.SetObjCArray(LV, E->getType()->isArrayType());
     return;
   }
diff --git a/lib/CodeGen/CGObjCGNU.cpp b/lib/CodeGen/CGObjCGNU.cpp
index e19debc..a08ec47 100644
--- a/lib/CodeGen/CGObjCGNU.cpp
+++ b/lib/CodeGen/CGObjCGNU.cpp
@@ -170,7 +170,8 @@
   virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
                                     llvm::Value *src, llvm::Value *dest);
   virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
-                                    llvm::Value *src, llvm::Value *dest);
+                                    llvm::Value *src, llvm::Value *dest,
+                                    llvm::Value *ivarOffset);
   virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
                                         llvm::Value *src, llvm::Value *dest);
   virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
@@ -1873,7 +1874,8 @@
 }
 
 void CGObjCGNU::EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
-                                   llvm::Value *src, llvm::Value *dst) {
+                                   llvm::Value *src, llvm::Value *dst,
+                                   llvm::Value *ivarOffset) {
   return;
 }
 
diff --git a/lib/CodeGen/CGObjCMac.cpp b/lib/CodeGen/CGObjCMac.cpp
index b9f4f34..bc4e7f9 100644
--- a/lib/CodeGen/CGObjCMac.cpp
+++ b/lib/CodeGen/CGObjCMac.cpp
@@ -369,9 +369,10 @@
 
   /// GcAssignIvarFn -- LLVM objc_assign_ivar function.
   llvm::Constant *getGcAssignIvarFn() {
-    // id objc_assign_ivar(id, id *)
+    // id objc_assign_ivar(id, id *, ptrdiff_t)
     std::vector<const llvm::Type*> Args(1, ObjectPtrTy);
     Args.push_back(ObjectPtrTy->getPointerTo());
+    Args.push_back(LongTy);
     llvm::FunctionType *FTy =
       llvm::FunctionType::get(ObjectPtrTy, Args, false);
     return CGM.CreateRuntimeFunction(FTy, "objc_assign_ivar");
@@ -1130,7 +1131,8 @@
   virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
                                     llvm::Value *src, llvm::Value *dest);
   virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
-                                  llvm::Value *src, llvm::Value *dest);
+                                  llvm::Value *src, llvm::Value *dest,
+                                  llvm::Value *ivarOffset);
   virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
                                         llvm::Value *src, llvm::Value *dest);
   virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
@@ -1360,7 +1362,8 @@
   virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
                                     llvm::Value *src, llvm::Value *dest);
   virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
-                                  llvm::Value *src, llvm::Value *dest);
+                                  llvm::Value *src, llvm::Value *dest,
+                                  llvm::Value *ivarOffset);
   virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
                                         llvm::Value *src, llvm::Value *dest);
   virtual void EmitGCMemmoveCollectable(CodeGen::CodeGenFunction &CGF,
@@ -2745,10 +2748,12 @@
 }
 
 /// EmitObjCIvarAssign - Code gen for assigning to a __strong object.
-/// objc_assign_ivar (id src, id *dst)
+/// objc_assign_ivar (id src, id *dst, ptrdiff_t ivaroffset)
 ///
 void CGObjCMac::EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
-                                   llvm::Value *src, llvm::Value *dst) {
+                                   llvm::Value *src, llvm::Value *dst,
+                                   llvm::Value *ivarOffset) {
+  assert(ivarOffset && "EmitObjCIvarAssign - ivarOffset is NULL");
   const llvm::Type * SrcTy = src->getType();
   if (!isa<llvm::PointerType>(SrcTy)) {
     unsigned Size = CGM.getTargetData().getTypeAllocSize(SrcTy);
@@ -2759,8 +2764,8 @@
   }
   src = CGF.Builder.CreateBitCast(src, ObjCTypes.ObjectPtrTy);
   dst = CGF.Builder.CreateBitCast(dst, ObjCTypes.PtrObjectPtrTy);
-  CGF.Builder.CreateCall2(ObjCTypes.getGcAssignIvarFn(),
-                          src, dst, "assignivar");
+  CGF.Builder.CreateCall3(ObjCTypes.getGcAssignIvarFn(),
+                          src, dst, ivarOffset);
   return;
 }
 
@@ -5268,11 +5273,12 @@
   return Builder.CreateLoad(Entry, false, "tmp");
 }
 /// EmitObjCIvarAssign - Code gen for assigning to a __strong object.
-/// objc_assign_ivar (id src, id *dst)
+/// objc_assign_ivar (id src, id *dst, ptrdiff_t)
 ///
 void CGObjCNonFragileABIMac::EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
                                                 llvm::Value *src,
-                                                llvm::Value *dst) {
+                                                llvm::Value *dst,
+                                                llvm::Value *ivarOffset) {
   const llvm::Type * SrcTy = src->getType();
   if (!isa<llvm::PointerType>(SrcTy)) {
     unsigned Size = CGM.getTargetData().getTypeAllocSize(SrcTy);
@@ -5283,8 +5289,8 @@
   }
   src = CGF.Builder.CreateBitCast(src, ObjCTypes.ObjectPtrTy);
   dst = CGF.Builder.CreateBitCast(dst, ObjCTypes.PtrObjectPtrTy);
-  CGF.Builder.CreateCall2(ObjCTypes.getGcAssignIvarFn(),
-                          src, dst, "assignivar");
+  CGF.Builder.CreateCall3(ObjCTypes.getGcAssignIvarFn(),
+                          src, dst, ivarOffset);
   return;
 }
 
diff --git a/lib/CodeGen/CGObjCRuntime.h b/lib/CodeGen/CGObjCRuntime.h
index a903ac3..6b45562 100644
--- a/lib/CodeGen/CGObjCRuntime.h
+++ b/lib/CodeGen/CGObjCRuntime.h
@@ -189,7 +189,8 @@
   virtual void EmitObjCGlobalAssign(CodeGen::CodeGenFunction &CGF,
                                     llvm::Value *src, llvm::Value *dest) = 0;
   virtual void EmitObjCIvarAssign(CodeGen::CodeGenFunction &CGF,
-                                  llvm::Value *src, llvm::Value *dest) = 0;
+                                  llvm::Value *src, llvm::Value *dest,
+                                  llvm::Value *ivarOffset) = 0;
   virtual void EmitObjCStrongCastAssign(CodeGen::CodeGenFunction &CGF,
                                         llvm::Value *src, llvm::Value *dest) = 0;
 
diff --git a/lib/CodeGen/CGValue.h b/lib/CodeGen/CGValue.h
index ee9dc52..2a06f51 100644
--- a/lib/CodeGen/CGValue.h
+++ b/lib/CodeGen/CGValue.h
@@ -156,6 +156,7 @@
   // Lvalue is a global reference of an objective-c object
   bool GlobalObjCRef : 1;
 
+  Expr *BaseIvarExp;
 private:
   void SetQualifiers(Qualifiers Quals) {
     this->Quals = Quals;
@@ -163,6 +164,7 @@
     // FIXME: Convenient place to set objc flags to 0. This should really be
     // done in a user-defined constructor instead.
     this->Ivar = this->ObjIsArray = this->NonGC = this->GlobalObjCRef = false;
+    this->BaseIvarExp = 0;
   }
 
 public:
@@ -185,6 +187,9 @@
   bool isGlobalObjCRef() const { return GlobalObjCRef; }
   bool isObjCWeak() const { return Quals.getObjCGCAttr() == Qualifiers::Weak; }
   bool isObjCStrong() const { return Quals.getObjCGCAttr() == Qualifiers::Strong; }
+  
+  Expr *getBaseIvarExp() const { return BaseIvarExp; }
+  void setBaseIvarExp(Expr *V) { BaseIvarExp = V; }
 
   unsigned getAddressSpace() const { return Quals.getAddressSpace(); }